The sympathetic and parasympathetic nature of neuropeptide Y-immunoreactive nerve fibres in the major salivary glands of the rat

Summary The distribution and origin of neuropeptide Y in the major salivary glands of the rat was studied by indirect immunofluorescence technique. Numerous nerve fibres immunoreactive for the peptide were seen in the parotid and sublingual glands. Most of the fibres were located around blood vessels and salivary acini. In the submandibular gland the number of immunoreactive nerve fibres around the acini was lower in comparison with that in the parotid and sublingual glands. Some immunoreactive nerve fibres were also found around or along intra- and interlobular ducts in all major salivary glands.A large number of the neuropeptide-containing neuronal cell bodies and nerve fibres were detected in the sympathetic superior cervical ganglion. Sympathetic postganglionic nerve trunks of this ganglion contained numerous immunoreactive nerve fibres as well. A subpopulation of the neuronal cell bodies in the submandibular ganglion were immunoreactive to neuropeptide Y.Both uni- and bilateral superior cervical ganglionectomies caused a significant decrease in the number of immunoreactive nerve fibres around the blood vessels in all the major salivary glands. However, these denervations did not affect the density of nerve fibres around the acini and ducts. On the contrary, unilateral parasympathetic denervation by sectioning the auriculotemporal nerve reduced the fibres around the secretory acini in the parotid gland remarkably, while only a minor reduction in the density of immunoreactive fibres associated with the blood vessels of the gland was detected. Unilateral electrocoagulation of the trigeminal nerve branches caused no detectable change in the density of immunoreactive nerve fibres in any of the major salivary glands.On the basis of the present findings it is concluded that neuropeptide Y-reactive nerve fibres present in all major salivary glands around the blood vessels seem to be mainly sympathetic, whereas those around the acini and ducts seems to be of parasympathetic origin.     

Gamma-aminobutyric acid (GABA) immunoreactivity in the mouse adrenal gland

Gamma-aminobutyric acid (GABA) immunoreactivity was revealed by immunocytochemistry in the mouse adrenal gland at the light and electron microscopic levels. Groups of weakly or faintly GABA immunoreactive chromaffin cells were often seen in the adrenal medulla. By means of immunohistochemistry combined with fluorescent microscopy, these GABA immunoreactive chromaffin cells showed noradrenaline fluorescence. The immunoreaction product was seen mainly in the granular cores of these noradrenaline cells. These results suggest the co-existence of GABA and noradrenaline within the chromaffin granules. Sometimes thick or thin bundles of GABA immunoreactive nerve fibers with or without varicosities were found running through the cortex directly into the medulla. In the medulla, GABA immunoreactive varicose nerve fibers were numerous and were often in close contact with small adrenaline cells and large ganglion cells; a few, however, surrounded clusters of the noradrenaline cells, where membrane specializations were formed. Single GABA immunoreactive nerve fibers, and thin or thick bundles of the immunoreactive varicose nerve fibers ran along the blood vessels in the medulla. The immunoreaction deposits were observed diffusely in the axoplasm and in small agranular vesicles of the GABA immunoreactive nerve fibers. Since no ganglion cells with GABA immunoreactivity were found in the adrenal gland, the GABA immunoreactive nerve fibers are regarded as extrinsic in origin.     

The origin and possible significance of substance P immunoreactive networks in the prevertebral ganglia and related structures in the guinea-pig

The distribution and origin of substance P immunoreactive nerve elements have been studied in the guinea-pig prevertebral ganglia by the indirect immunohistochemical technique, using a monoclonal antibody to substance P. Non-varicose substance P immunoreactive nerve fibres enter or leave the ganglia in all nerves associated with them, traversing the ganglia in larger or smaller bundles. Networks, mainly single-stranded, of varicose substance P immunoreactive nerve fibres also permeate the ganglia, forming a loose meshwork among the neurons. Similar networks are present in the lumbar paravertebral ganglia. In all these ganglia, neuronal somata do not in general show substance P immunoreactivity. The various nerves connected with the inferior mesenteric ganglion have been cut, in single categories and in various combinations, and the ganglion examined, after intervals of up to six days. Cutting the colonic or hypogastric nerves, which connect the ganglion with the hindgut and pelvic organs, leads to accumulation of substance P immunoreactive material in their ganglionic stumps, extending retrogradely to intraganglionic non-varicose fibres traceable through into the intermesenteric and lumbar splanchnic nerves. There is some local depletion of intraganglionic varicose networks. Cutting the intermesenteric nerve, which connects the coeliac-superior mesenteric ganglion complex with the ganglion, leads to accumulation of substance P immunoreactive material in its cranial stump and depletion of its distal stump; a minimal depletion is detectable in the inferior mesenteric ganglion itself. Cutting the lumbar splanchnic nerves, which connect the ganglion with the upper lumbar spinal cord and dorsal root ganglia, leads to accumulation of substance P immunoreactive material in their proximal stumps and total depletion of their distal, ganglionic stumps; in the ganglion there is subtotal loss of non-varicose substance P immunoreactive fibres and of varicose nerve networks, and the few surviving non-varicose fibres are traceable across the ganglion from the intermesenteric nerve to the colonic and hypogastric nerves. Cutting the intermesenteric and lumbar splanchnic nerves virtually abolishes substance P immunoreactive elements from the ganglion within three days postoperatively. It is concluded that these arise centrally to the ganglion.(ABSTRACT TRUNCATED AT 400 WORDS)     

Localization of monoamine nerve fibres by formaldehyde fluorescence histochemistry in the posterior salivary duct and gland of Octopus vulgaris.

A bright yellow-green specific fluorescence is induced by formaldehyde histochemistry for monoamines in the secretory nerve trunks of the Octopus vulgaris posterior salivary duct, and in their ramification in the gland tubules. In contrast, the motor nerve trunks of the duct contain few fluorescent elements. The muscular and connective coat of the duct is provided with fluorescent globular and varicose structures, of various sizes and colours, which become numerous in the duct branches. At least some of these peripheral structures belong to varicose monoamine nerve fibres. In the gland, on the contrary, the muscle cells surrounding the tubules are not supplied with fluorescent nerve fibres.     

Histochemical phenotypes of von Ebner's gland of ferret and their functional implications

Von Ebner's gland of ferret was examined by means of light microscopy, protein, mucosubstance and enzyme histochemistry, and neurohistology. Acinar cells were replete with granules containing neutral mucosubstances and disulphides, and showed strong diffuse acid phosphatase activity and weak granular staining for peroxidase. Staining for cytochrome oxidase, succinate dehydrogenase, and NADH and NAD(P)H dehydrogenases was also seen. Basolateral plasmalemma of acinar cells showed weak, ouabain-sensitive Na⁺,K⁺-ATPase activity. Ductal cells were of a simple appearance, contained thiols and showed variable staining for acid phosphatase, dehydrogenases and cytochrome oxidase. Variable amounts of -glucuronidase reaction product were localized in the glandular parenchyma, being marked in atrophic areas. Prominent stellate myoepithelial cells embracing acini and also basal ductal cells were demonstrated by alkaline phosphatase. Thiamine pyrophosphatase reaction product was concentrated in blood vessels around parenchyma, with little Golgi-like staining in acinar cells. Acetylcholinesterase activity was associated with an extensive network of nerve fibres embracing parenchyma, whereas catecholamine fluorescence was not seen. The results suggest that the acini of von Ebner's gland of ferret synthesise neutral secretory glycoproteins and peroxidase. Water mobilization is inconspicuous. Lysosomal activities feature in the parenchyma, possibly a consequence of processing secretory products in acini, absorption in ducts and/or adaptation atrophy. The gland receives a rich cholinergic-type innervation, and has extensive myoepithelial and microvascularbreak networks.     

The origin and distribution of adrenergic nerve fibres in the guinea-pig colon

Summary A detailed study of the origin and distribution of sympathetic fibres in the distal colon of the guinea-pig has been made using the fluorescent histochemical method for localizing catecholamines. The extrinsic adrenergic fibres of the colonie sympathetic nerves follow the inferior mesenteric artery and its branches to the colon. Some of the extrinsic adrenergic fibres are associated with the parasympathetic fibres of the pelvic nerves near the colon. Complete adrenergic denervation follows the removal of the inferior mesenteric ganglion or the destruction of the nerves running with the inferior mesenteric artery.No fluorescent fibres, other than those associated with blood vessels, were observed in air-dried stretch preparations of the isolated longitudinal muscle. However, a substantial number of varicose, terminal fibres, not associated with blood vessels, were observed in the circular muscle. Some varicose fibres, apart from those associated with ganglion cells, were observed in the myenteric plexus. These fibres were seen in the bundles of nerves running between the nodes of the plexus and also as single fibres which branched from the plexus to end in areas free of ganglion cells.Three plexuses of adrenergic nerve fibres have been distinguished in the submucosa: a dense plexus of terminal fibres innervating both the veins and arteries; a plexus consisting of innervated nodes of ganglion cells, connected by bundles of fluorescent and non-fluorescent nerves; and a plexus of varicose and non-varicose fibres, which is not associated with ganglion cells. Some groups of ganglion cells in the submucosa were without adrenergic innervation.A plexus of varicose fibres forms a meshwork in the lamina propria of the mucosa. The muscularis mucosae is sparsely innervated. Most of the blood vessels in the mucosa are not associated with adrenergic fibres.     

Substance P-immunoreactive nerve fibres in the anterior segment of the rabbit eye

Summary Substance P-immunoreactive nerve terminals were found in several locations in the anterior segment of the rabbit eye. In the iris they occurred in the sphincter muscle and were randomly distributed in the iris stroma with some fibres running close to the dilator muscle. In the ciliary body these immunoreactive elements were few and occurred within bundles of nerve fibres, while in the ciliary processes they were more numerous with a predominantly subepithelial location. Blood vessels in the anterior uvea were often surrounded by substance P-immunoreactive fibres. No substance P-fibres were found in the cornea, while the sclera contained very few such elements.Using conventional in vitro techniques it was found that the sphincter pupillae muscle of the iris responded to electrical stimulation with a contraction that was resistant to cholinergic and adrenergic blockade, but was inhibited by the neuronal blocker tetrodotoxin. This indicates the existence of a non-cholinergic, non-adrenergic neuronal mediator of the contractile response. Exogenously applied substance P produced a long-lasting contraction of the spincter muscle, an observation compatible with the view that substance P is the noncholinergic, non-adrenergic neurotransmitter involved.     

Peptidergic regulation of secretory activity in amphibian olfactory mucosa: Immunohistochemistry,neural stimulation,and pharmacology

Summary The role of substance P in the regulation of secretion from sustentacular cells, Bowman's glands and deep glands in the amphibian olfactory mucosa was investigated using immunohistochemical, electrophysiological, and pharmacological methods. Substance P-like immunoreactive varicose fibers extended through the olfactory epithelium, terminating at or near the surface. In addition, immunoreactive varicose fibers innervated Bowman's glands, deep glands, and blood vessels in the lamina propria. Innervation of Bowman's gland was sparse, with fibers terminating on basal acinar cell membranes; deep gland innervation was abundant, with fibers often extending between acinar cells almost to the lumen. Stimulation of the ophthalmic branch of the trigeminal nerve resulted in slow potentials recorded at the surface of the olfactory epithelium. When the olfactory mucosae from trigeminal-stimulated animals were examined histologically, morphological signs of secretory activity were observed, suggesting that substance P was released from the trigeminal nerve terminals. Topical application of 10^-5 to 10^-3 mol substance P resulted in morphological signs of secretion that were very similar to those seen as a result of trigeminal stimulation. Thus, substance P released from trigeminal fibers may modulate secretory activity within the olfactory mucosa.     

Plasticity in expression of calcitonin gene-related peptide and substance P immunoreactivity in ganglia and fibres following guanethidine and/or capsaicin denervation

Summary This study was designed to investigate the effects of multiple denervation procedures on calcitonin gene-related peptide- and substance P-immunoreactive neurons in sympathetic and sensory cranial ganglia and in selected targets. Sympathectomy by long-term guanethidine treatment induced a pronounced increase in calcitonin gene-related peptide-immunoreactive and substance P-immunoreactive nerve fibres in all the tissues investigated, in contrast to a significant reduction of immunoreactive cell bodies. Neonatal capasaicin treatment abolished substance P immunoreactivity in many targets and caused a dramatic reduction of substance P-immunoreactive sensory nerve cell bodies; calcitonin gene-related peptide-immunoreactive nerve density was decreased, but the number of immunoreactive nerve cell bodies was unchanged. Guanethidine treatment of capsaicin-injected rats reversed the loss of calcitonin gene-related peptide-immunoreactive nerves, but not that of substance P-immunoreactive neurons. In the iris, capsaicin treatment had little effect on calcitonin gene-related peptide- and substance P-immunoreactive nerves, suggesting that in rats the majority of these fibres originate from capsaicin-insensitive neurons. The results suggest that the denervation procedures used in this study alter the synthesis and transport of neuropeptides in sensory neurons in conjunction with changes in the number of nerve fibres.     

An immuno-electron-microscopic study of the localization of VIP-like immunoreactivity in the adrenal gland of the rat

Summary VIP-like immunoreactivity was revealed in a few chromaffin cells, medullary ganglion cells and a plexus of varicose nerve fibers in the superficial cortex and single varicose fibers in the juxtamedullary cortex and the medulla of the rat adrenal gland. VIP-like immunoreactive chromaffin cells were polygonal in shape without any distinct cytoplasmic processes and they appeared solitarily. Their cytoplasm contained abundant granular vesicles having a round core and the immunoreactive material was localized to the granular core. VIP-immunoreactive ganglion cells were multipolar and had large intracytoplasmic vacuoles. The immunoreactive material was localized not only in a few granular vesicles but also diffusely throughout the axoplasm. VIP-immunoreactive varicose nerve fibers in the superficial cortex were characterized by abundant small clear vesicles and some large granular vesicles, while those in the juxtamedullary cortex and medulla and the ganglionic processes were characterized by abundant large clear vesicles, as well as the same vesicular elements as contained in the nerves in the superficial cortex. The immunoreactive material was localized on the granular cores and diffusely in the axoplasm in both nerves. Based on the similarity and difference in the composition of the vesicles contained in individual nerves, it is likely that the VIP-immunoreactive nerve fibers in the medulla and the juxtamedullary cortex are derived from the medullary VIP-ganglion cells, while those in the superficial cortex are of extrinsic origin. The immunoreactive nerve fibers in both the cortex and the medulla were often in direct contact with cortical cells and chromaffin cells, where no membrane specializations were formed. The immunoreactive nerve fibers were sometimes associated with the smooth muscle cells and pericytes of small blood vessels in the superficial cortex. In addition they were often seen in close apposition to the fenestrated endothelial cells in the cortex and the medulla, only a common basal lamina intervening. Several possible mechanisms by which VIP may exert its effect in the adrenal gland are discussed.     

Pituitary adenylate cyclase activating polypeptide (PACAP) in the rat mammary gland

Pituitary adenylate cyclase activating polypeptide (PACAP), a member of the vasoactive intestinal polypeptide (VIP) family of peptides, is present in the brain and in neuronal elements of a number of peripheral organs. Since no information on PACAP in the mammary gland exists, we have investigated, by radioimmunoassay and immunohistochemistry, the occurrence and distribution of PACAP immunoreactivity in the mammary gland of lactating and non-lactating rats. A specific monoclonal mouse anti-PACAP antibody'has been used to show that the peptide is located in nerve fibres associated with bundles of circular and longitudinal smooth muscle surrounding the lactiferous duct of the nipple. PACAP-immunoreactive nerve fibres and nerve bundles are present in the subepidermal connective tissue of the nipple and in the mammary parenchyma, some of the fibres being in close contact with blood vessels. Occasionally, a few delicate varicose fibres are associated with secretory alveoli and lactiferous ducts. The majority of PACAP-positive nerve fibres are, however, located in the glabrous skin of the nipple and the hairy skin adjacent to the nipple forming a subepithelial plexus from which delicate varicose nerve fibres enter the overlying epithelium. Double immunostaining for PACAP and a marker for sensory neurons, calcitonin gene-related peptide, has disclosed that the two peptides are almost completely co-localized. A minor population of the PACAP-immunoreactive nerve fibres shows co-existence with VIP. Although no obvious changes at the immunohistochemical level could be observed during pregnancy or lactation, elevated concentrations of immunoreactive PACAP-38 in mammary extracts have been found during lactation. Our data suggest that PACAP is involved in the nervous control of mammary gland function, probably in the transmission of suckling stimuli.     

Adrenergic Nerves in the Avian Eye and Ciliary Ganglion

Summary The distribution of adrenergic fibres to the eye and to the ciliary ganglion was studied in pigeons, chicken and ducks with the aid of the sensitive and highly specific fluorescence method of Falck and Hillarp. In some animals the intensity of the fluorescence was increased by treating the animals with Nialamide and 1-DOPA. The cornea contained no adrenergic fibres except at the limbus, where a plexus of adrenergic varicose fibres was seen, partly associated with vessels. In the chamber angle, adrenergic varicose fibres were common in the loose connective tissue covering the canal of Schlemm. The canal of Schlemm was supplied by only few adrenergic fibres, but such fibres appeared along the intrascleral aqueous drainage vessels. In the iris, adrenergic varicose fibres appeared immediately in front of the posterior layer of pigment cells, strongly indicating the presence of a dilator homologous with that seen in mammals. The frontal third of the stroma contained several adrenergic varicose fibres, many of which seemed to lack association with any vessel. Varicose adrenergic fibres were also sparsely seen in the striated muscle of the iris. The ciliary processes contained many adrenergic varicose fibres, at least part of which seemed to be associated with the ciliary epithelium. The striated muscles of the ciliary body contained adrenergic varicose fibres along the vessels only. The retina contained adrenergic varicose fibres in three layers in the inner plexiform layer. Adrenergic ganglion cells of two sizes were detected in the inner nuclear layer. The retinal vessels had no adrenergic nerve fibres. The pecten was also devoid of adrenergic nerve fibres, except along the vessels close to the papilla. The optic nerve contained adrenergic varicose nerve fibres along vessels only. In the ciliary ganglion, varicose adrenergic fibres appeared at the small ganglion cells, often forming baskets of synaptic character.Acknowledgements. The work has been supported by the United States Public Health Service (grant NB 06701-01), by the Swedish Medical Research Council (project B 67-12 X-712-02 A) and by the Faculty of Medicine, University of Lund, Sweden.     

Ganglion cells immunoreactive for catecholamine-synthesizing enzymes,neuropeptide Y and vasoactive intestinal polypeptide in the rat adrenal gland

Immunohistochemistry has been used to demonstrate tyrosine hydroxylase (TH), dopamine--hydroxylase (DBH), phenylethanolamine N-methyltransferase (PNMT), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) immunoreactivities, and acetylcholinesterase (AChE) activity was demonstrated in rat adrenal glands. The TH, DBH, NPY and VIP immunoreactivities and AChE activity were observed in both the large ganglion cells and the small chromaffin cells whereas PNMT immunoreactivity was found only in chromaffin cells, and not in ganglion cells. Most intraadrenal ganglion cells showed NPY immunoreactivity and a few were VIP immunoreactive. Numerous NPY-immunoreactive ganglion cells were also immunoreactive for TH and DBH; these cells were localized as single cells or groups of several cells in the adrenal cortex and medulla. Use of serial sections, or double and triple staining techniques, showed that all TH- and DBH-immunoreactive ganglion cells also showed NPY immunoreactivity, whereas some NPY-immunoreactive ganglion cells were TH and DBH immunonegative. NPY-immunoreactive ganglion cells showed no VIP immunoreactivity. AChE activity was seen in VIP-immunopositive and VIP-immunonegative ganglion cells. These results suggest that ganglion cells containing noradrenaline and NPY, or NPY only, or VIP and acetylcholine occur in the rat adrenal gland; they may project within the adrenal gland or to other target organs. TH, DBH, NPY, and VIP were colocalized in numerous immunoreactive nerve fibres, which were distributed in the superficial adrenal cortex, while TH-, DBH- and NPY-immunoreactive ganglion cells and nerve fibres were different from VIP-immunoreactive ganglion cells and nerve fibres in the medulla. This suggests that the immunoreactive nerve fibres in the superficial cortex may be mainly extrinsic in origin and may be different from those in the medulla.     

CGRP-immunoreactive sensory nerve fibers in the submandibular gland of the rat

Summary Indirect immunofluorescence technique was used to study the occurrence and distribution of CGRP immunoreactivity in the submandibular gland of normal rats and after unilateral sensory and sympathetic denervations. In normal rats, CGRP-immunoreactive nerve fibers and nerve trunks were seen around or in close contact with interlobular salivary ducts as well as around small blood vessels of the gland. Occasionally, CGRP-immunoreactive nerve fibers were also detected between or around the acini of the gland.The submandibular ganglia contained CGRP-immunoreactive nerve fibers, but the ganglion cells were not immunoreactive for CGRP. The trigeminal ganglion contained a population of CGRP-immunoreactive, mainly small sized ganglion cells and nerve fibers distributed throughout the ganglion. Unilateral electrocoagulation of the trigeminal nerve caused a significant reduction in the number of immunoreactive nerve fibers in the gland, although some fibers still were present in the ipsilateral glandular tissue. Unilateral superior cervical ganglionectomy caused no detectable effect on the number of CGRP-immunoreactive nerve fibers in the gland.The present results suggest that the rat submandibular gland contains CGRP-immunoreactive nerve fibers both around blood vessels and in glandular secretory elements. Denervation experiments support the view that the majority, but perhaps not all of them originate from the trigeminal ganglion.     

Immunohistochemical study on the distribution of vasoactive intestinal polypeptide (VIP) containing nerve fibers in the chicken pancreas

The distribution of vasoactive intestinal polypeptide (VIP) containing nervous elements in the chicken pancreas was immunohistochemically investigated by light microscopy. Strongly VIP immunoreactive ganglia existed in the interlobular connective tissue. Ganglion containing both VIP immunoreactive and non-immunoreactive nerve cells was occasionally observed in the connective tissue. Almost all the ganglion cells also showed acetylcholinesterase (AChE) activity. No extrapancreatic nerve bundles containing VIP immunoreactive nerve fibres were detected. VIP immunoreactive nerve fibres formed plexuses in the subepithelial layer of secretory ducts and the muscle layer of small arteries. The distribution pattern of VIP immunoreactive nerve fibers was similar to that of AChE-positive nerve fibers on adjacent sections. The exocrine pancreas received a rich supply of varicose nerve fibers showing VIP immunoreactivity. B-islets also were richly innervated by VIP immunoreactive varicose nerve fibers, whereas A-islets, only poorly. These observations suggest that VIP containing nerves in the chicken pancreas have an intrinsic origin, are probably derived from VIP immunoreactive, intrapancreatic ganglion cells and innervate secretory ducts, arteries, acinar cells and B-islets, and that VIP must coexist with acetylcholine in the nervous elements.     

Colocalization of neuropeptides and NADPH-diaphorase in the intra-adrenal neuronal cell bodies and fibres of the rat

Colocalization of vasoactive intestinal peptide, neuropeptide Y, calcitonin gene-related peptide, substance P, and tyrosine hydroxylase, respectively, with NADPH-diaphorase staining in rat adrenal gland was investigated using the double labelling technique. All vasoactive intestinal peptide- and some neuropeptide Y-immunoreactive intrinsic neuronal cell bodies seen in the gland were double stained with NADPH-diaphorase. Double labelling also occurred in some nerve fibres immunoreactive to vasoactive intestinal peptide and neuropeptide Y in the medulla and cortex. No colocalization of calcitonin gene-related peptide, substance P or tyrosine hydroxylase immunoreactivity with NADPH-diaphorase staining was observed. However, nerve fibres with varicosities immunoreactive for all the neuropeptides examined were closely associated with some of the NADPH-diaphorase-stained neuronal cell bodies. Thus, in rat adrenal gland, nitric oxide is synthesized in all ganglion cells containing vasoactive intestinal peptide and in some containing neuropeptide Y, but not in those containing calcitonin gene-related peptide, substance P or tyrosine hydroxylase.     

CGRP-immunoreactive sensory nerve fibers in the submandibular gland of the rat

Indirect immunofluorescence technique was used to study the occurrence and distribution of CGRP immunoreactivity in the submandibular gland of normal rats and after unilateral sensory and sympathetic denervations. In normal rats, CGRP-immunoreactive nerve fibers and nerve trunks were seen around or in close contact with interlobular salivary ducts as well as around small blood vessels of the gland. Occasionally, CGRP-immunoreactive nerve fibers were also detected between or around the acini of the gland. The submandibular ganglia contained CGRP-immunoreactive nerve fibers, but the ganglion cells were not immunoreactive for CGRP. The trigeminal ganglion contained a population of CGRP-immunoreactive, mainly small sized ganglion cells and nerve fibers distributed throughout the ganglion. Unilateral electrocoagulation of the trigeminal nerve caused a significant reduction in the number of immunoreactive nerve fibers in the gland, although some fibers still were present in the ipsilateral glandular tissue. Unilateral superior cervical ganglionectomy caused no detectable effect on the number of CGRP-immunoreactive nerve fibers in the gland. The present results suggest that the rat submandibular gland contains CGRP-immunoreactive nerve fibers both around blood vessels and in glandular secretory elements. Denervation experiments support the view that the majority, but perhaps not all of them originate from the trigeminal ganglion.     

Noradrenergic and peptidergic innervation of the mammary gland in the immature pig

The presence and pattern of coexistence of some biologically active substances in nerve fibres supplying the mammary gland in the immature pig were studied using immunohistochemical methods. The substances studied included: protein gene product 9.5 (PGP), tyrosine hydroxylase (TH), somatostatin (SOM), neuropeptide Y (NPY), galanin (GAL), calcitonin gene-related peptide (CGRP) and substance P (SP). The mammary gland was found to be richly supplied by PGP-immunoreactive (PGP-IR) nerve fibres that surrounded blood vessels, bundles of smooth muscle cells and lactiferous ducts. The vast majority of these nerves also displayed immunoreactivity to TH. Immunoreactivity to SOM was observed in a moderate number of nerve fibres which were associated with smooth muscles of the nipple and blood vessels. Immunoreactivity to NPY occurred in many nerve fibres associated with blood vessels and in single nerves supplying smooth muscle cells. Solitary GAL-IR axons supplied mostly blood vessels. Many CGRP-IR nerve fibres were associated with both blood vessels and smooth muscles. SP-IR nerve fibres richly supplied blood vessels only. The colocalization study revealed that SOM, NPY and GAL partly colocalized with TH in nerve fibres supplying the porcine mammary gland.     

Effect of subcutaneous pancreatic tissue transplants on streptozotocin-induced diabetes in rats. III. Distribution of neuropeptides in normal and diabetic (host) pancreas.

This study examines whether there is a change in the pattern of distribution of cholecystokinin-octapeptide (CCK-8), calcitonin-gene-related peptide (CGRP), neuropeptide-Y (NPY), substance P (SP) and vasoactive intestinal polypeptide (VIP) in the pancreas of streptozotocin (STZ)-diabetic (host) rats after subcutaneous pancreatic transplantation. Varicose CCK-8-immunopositive nerve fibres were observed in the wall of blood vessels of both normal and diabetic host pancreata. The density of CCK-8-immunoreactive varicose nerve fibres appeared to have increased in host rat pancreas. CGRP was demonstrated in many nerve fibres located in the wall of blood vessels of both normal and host pancreas. CGRP, however, seemed to be better expressed in the nerves of host pancreas when compared to normal. The pancreata of both normal and diabetic (host) rats contained numerous NPY-immunopositive varicose nerve fibres located in the wall of blood vessels. SP was demonstrated in neurons located in the interlobular areas of normal tissue and in fine varicose nerve fibres of the interacinar region of the pancreas of STZ-induced diabetic rats with SPTG. In normal pancreatic tissue, VIP-immunopositive nerve fibres were observed in all areas of the pancreas. VIP-positive nerve fibres were still discernible especially in the interacinar regions of the pancreas of host rats. In conclusion, the pattern of distribution and density of NPY, SP and VIP in the pancreas of STZ-induced diabetic rats with SPTG is similar to that observed in normal pancreas, but the expression of CGRP and CCK-8 seemed to have increased as a result of transplantation and or diabetes.     

Immunohistochemical and ultrastructural localisation of peptide-containing nerves and myocardial cells in the human atrial appendage

Summary The innervation and myocardial cells of the human atrial appendage were investigated by means of immunocytochemical and ultrastructural techniques using both tissue sections and whole mount preparations. A dense innervation of the myocardium, blood vessels and endocardium was revealed with antisera to general neuronal (protein gene product 9.5 and synaptophysin) and Schwann cell markers (S-100). The majority of nerve fibres possessed neuropeptide Y immunoreactivity and were found associated with myocardial cells, around small arteries and arterioles at the adventitial-medial border and forming a plexus in the endocardium. Subpopulations of nerve fibres displayed immunoreactivity for vasoactive intestinal polypeptide, somatostatin, substance P and calcitonin gene-related peptide. In whole-mount preparations of endocardium, substance P and calcitonin gene-related peptide immunoreactivities were found to coexist in the same varicose nerve terminals. Ultrastructural studies revealed the presence of numerous varicose terminals associated with myocardial, vascular smooth muscle and endothelial cells. Neuropeptide Y immunoreactivity was localised to large electron-dense secretory vesicles in nerve terminals which also contained numerous small vesicles. Atrial natriuretic peptide immunoreactivity occurred exclusively in myocardial cells where it was localised to large secretory vesicles. The human atrial appendage comprises a neuroendocrine complex of peptidecontaining nerves and myocardial cells producing ANP.