Localization of bombesin-, neuropeptide Y-, enkephalin-and tyrosine hydroxylase-like immunoreactivities in rat coeliac-superior mesenteric ganglion

Summary The localization of bombesin- (BOMB) and enkephalin-(ENK) immunoreactive (IR) nerves was studied in rat coeliac-superior mesenteric ganglion complex in relation to neuropeptide Y (NPY)- and tyrosine hydroxylase (TH)-immunoreactive neurons with an immunofluorescence double-staining method. Very dense networks of BOMB-IR nerve terminals surrounded the majority of the principal ganglion cells, wheter or not they were TH-IR. BOMB-IR nerves were specifically related to the non-NPY-IR neurons. Moderately dense networks of ENK-IR fibers were unevenly distributed among the ganglion cells. Majority of these neurons exhibited TH-IR and some of them also contained NPY-IR. In sections double stained with antibodies to ENK and BOMB some nerve fibers contained both peptides. The findings suggest that BOMB-IR nerves, which have been previously demonstrated to originate from gut, control the function of non-NPY-IR ganglion cells. ENK-IR nerves apparently control the adrenergic neurons which project to gut and also some NPY-IR vasomotoric neurons. The finding that ENK- and BOMB-IR coexist in some nerves suggests that some ENK-IR nerves may originate from gut, although the major part probably represents preganglionic fibers originating from spinal cord.     

Localization of bombesin-, neuropeptide Y-, enkephalin- and tyrosine hydroxylase-like immunoreactivities in rat coeliac-superior mesenteric ganglion

The localization of bombesin- (BOMB) and enkephalin- (ENK) immunoreactive (IR) nerves was studied in rat coeliac-superior mesenteric ganglion complex in relation to neuropeptide Y (NPY)- and tyrosine hydroxylase (TH)-immunoreactive neurons with an immunofluorescence double-staining method. Very dense networks of BOMB-IR nerve terminals surrounded the majority of the principal ganglion cells, whether or not they were TH-IR. BOMB-IR nerves were specifically related to the non-NPY-IR neurons. Moderately dense networks of ENK-IR fibers were unevenly distributed among the ganglion cells. Majority of these neurons exhibited TH-IR and some of them also contained NPY-IR. In sections double stained with antibodies to ENK and BOMB some nerve fibers contained both peptides. The findings suggest that BOMB-IR nerves, which have been previously demonstrated to originate from gut, control the function of non-NPY-IR ganglion cells. ENK-IR nerves apparently control the adrenergic neurons which project to gut and also some NPY-IR vasomotoric neurons. The finding that ENK- and BOMB-IR coexist in some nerves suggests that some ENK-IR nerves may originate from gut, although the major part probably represents preganglionic fibers originating from spinal cord.     

Tyrosine hydroxylase- and neuropeptide Y-immunoreactive nerve fibers in the pineal complex of untreated rats and rats following removal of the superior cervical ganglia

Summary The distribution of tyrosine hydroxylase (TH)- and neuropeptide Y (NPY)-immunoreactive(IR) nerve fibers in the pineal complex was investigated in untreated rats and rats following bilateral removal of the superior cervical ganglia. In normal animals, a large number of TH- and NPY-IR nerve fibers were present in the pineal capsule, the perivascular spaces, and intraparenchymally between the pinealocytes throughout the superficial pineal and deep pineal gland. A small number of TH-IR and NPY-IR nerve fibers were found in the posterior and habenular commissures, a few fibers penetrating from the commissures into the deep pineal gland. To elucidate the origin of these fibers, the superior cervical ganglion was removed bilaterally in 10 animals, and the pineal complex was examined immunohistochemically. Two weeks after the ganglionectomy, the TH-IR and NPY-IR nerve fibers in the superficial pineal gland had almost completely disappeared. On the other hand, in the deep pineal and the pineal stalk, the TH-IR and NPY-IR fibers were still present after ganglionectomy. These data show that the deep pineal gland and the pineal stalk possess an extrasympathetic innervation by TH-IR and NPY-IR fibers. It is suggested that the extrasympathetic TH-IR and NPY-IR nerve fibers innervating the deep pineal and the pineal stalk originate from the brain.     

Neuropeptide Y: presence in sympathetic and parasympathetic innervation of the nasal mucosa

Summary The occurrence of neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI) in the sympathetic and parasympathetic innervation of the nasal mucosa was studied in various species including man. A dense network of NPY-immunoreactive (IR) fibres was present around arteries and arterioles in the nasal mucosa of all species studied. NPY was also located in nerves around seromucous glands in pig and guinea-pig, but not in rat, cat and man. The NPY-IR glandular innervation corresponded to about 20% of the NPY content of the nasal mucosa as revealed by remaining NPY content determined by radioimmunoassay after sympathectomy. These periglandular NPY-positive fibres had a distribution similar to the VIP-IR and PHI-IR nerves but not to the noradrenergic markers tyrosine hydroxylase (TH) or dopamine--hydroxylase (DBH). The NPY nerves around glands and some perivascular fibres were not influenced by sympathectomy and probably originated in the sphenopalatine ganglion where NPY-IR and VIP-IR ganglion cells were present. The venous sinusoids were innervated by NPY-positive fibres in all species except the cat. Dense NPY and DBH-positive innervation was seen around thick-walled vessels in the pig nasal mucosa; the latter may represent arterio-venous shunts. Double-labelling experiments using TH and DBH, and surgical sympathectomy revealed that the majority of NPY-IR fibres around blood vessels were probably noradrenergic. The NPY-positive perivascular nerves that remained after sympathectomy in the pig nasal mucosa also contained VIP/PHI-IR. The major nasal blood vessels, i.e. sphenopalatine artery and vein, were also densely innervated by NPY-IR fibres of sympathetic origin. Perivascular VIP-IR fibres were present around small arteries, arterioles, venous sinusoids and arterio-venous shunt vessels of the nasal mucosa whereas major nasal vessels received only single VIP-positive nerves. The trigeminal ganglion of the species studied contained only single TH-IR or VIP-IR but no NPY-positive ganglion cells. It is concluded that NPY in the nasal mucosa is mainly present in perivascular nerves of sympathetic origin. In some species, such as pig, glandular and perivascular parasympathetic nerves, probably of VIP/PHI nature, also contain NPY.     

Distribution and origin of substance P and neuropeptide Y-immunoreactive nerves in the guinea-pig heart

Summary The localization and origin of substance P (SP)-, neuropeptide Y (NPY)-, and noradrenaline/tyrosine hydroxylase (NA/TH)-immunoreactive (IR) nerves in the guinea-pig heart were investigated by means of immunohistochemistry; quantitative analysis was performed by radioimmunoassay (NPY) and high performance liquid chromatography (NA). Both untreated animals and animals subjected to stellatectomy, combined stellatectomy and local capsaicin pretreatment of the vagal nerves or systemic application of capsaicin were studied. A dense network of SP-IR nerves was observed in the right atrium in different locations: (1) around local cardiac ganglion cells, (2) close to blood vessels, (3) within the myocardium, and (4) close to and within peri and endocardium.A moderately dense SP-innervation, mainly related to blood vessels, was found in the ventricles. Very dense networks of NPY and TH-IR nerve fibers with an overlapping distributional pattern around blood vessels and in the myocardium were seen in both the atria and the ventricles. In addition, some cell bodies in local cardiac ganglia were NPY-IR. Bilateral stellatectomy resulted in a reduction of SP-IR in the right atrium (55% of control), which was more pronounced after additional capsaicin pretreatment of the vagal nerves (44% of control).In the left ventricle no significant depletion of SP-IR was seen by either stellatectomy or combined stellatectomy and capsaicin treatment of the vagal nerves. It was not possible to establish any defined target areas within the heart for vagal or spinal SP-IR afferents by use of immunohistochemical methods. Systemic capsaicin treatment caused a total loss of SP-IR nerves in the heart. After bilateral stellatectomy the levels of NPY-IR and NA were reduced to about 10% of control in both the right atrium and left ventricle. In accordance, NPY and TH-IR nerves were also almost totally absent in the heart after bilateral stellatectomy.     

Postnatal development of autonomic and sensory innervation of thoracic hairy skin in the rat

Summary Histochemical, immunocytochemical, and radioenzymatic techniques were used to examine the neurotransmitter-related properties of the innervation of thoracic hairy skin in rats during adulthood and postnatal development. In the adult, catecholamine-containing fibers were associated with blood vessels and piloerector muscles, and ran in nerve bundles throughout the dermis. The distribution of tyrosine hydroxylase (TH)-immunoreactive (IR) fibers was identical. Neuronal fibers displaying neuropeptide Y (NPY) immunoreactivity were seen in association with blood vessels. Double-labeling studies suggested that most, if not all, NPY-IR fibers were also TH-IR and likewise most, if not all, vessel-associated TH-IR fibers were also NPY-IR. Calcitonin gene-related peptide (CGRP)-IR fibers were observed near and penetrating into the epidermis, in close association with hair follicles and blood vessels, and in nerve bundles. A similar distribution of substance P (SP)-IR fibers was evident. In adult animals treated as neonates with the sympathetic neurotoxin 6-hydroxydopamine, a virtual absence of TH-IR and NPY-IR fibers was observed, whereas the distribution of CGRP-IR and SP-IR fibers appeared unaltered. During postnatal development, a generalized increase in the number, fluorescence intensity, and varicose morphology of neuronal fibers displaying catecholamine fluorescence, NPY-IR, CGRP-IR, and SP-IR was observed. By postnatal day 21, the distribution of the above fibers had reached essentially adult levels, although the density of epidermal-associated CGRP-IR and SP-IR fibers was significantly greater than in the adult. The following were not evident in thoracic hairy skin at any timepoint examined: choline acetyltransferase activity, acetylcholinesterase histochemical staining or immunoreactivity, fibers displaying immunoreactivity to vasoactive intestinal peptide, cholecystokinin, or leucine-enkephalin. The present study demonstrates that the thoracic hairy skin in developing and adult rats receives an abundant sympathetic catecholaminergic and sensory innervation, but not a cholinergic innervation.     

Galanin is more common than NPY in vascular sympathetic neurons of the brush-tailed possum.

The distribution of galanin (Gal) in sympathetic vascular neurons of adult and juvenile brush-tailed possums (Trichosurus vulpecula), was examined using double-labelling immunohistochemistry. This was compared with the distribution of neuropeptide Y (NPY) in the same tissues. Immunoreactivity (IR) to galanin was present in the majority (64-99%) of nerve cell bodies in paravertebral sympathetic ganglia, where it mostly co-existed with IR to the catecholamine-synthesizing enzyme, tyrosine hydroxylase (TH). Gal-IR also was present in most, if not all, TH-IR perivascular axons supplying systemic arteries and veins. NPY-IR was less common than Gal-IR in all sympathetic ganglia and perivascular axons examined. Some sympathetic, TH-IR axons supplying the abdominal aorta and renal artery contained both Gal-IR and NPY-IR, while TH-IR axons supplying cephalic and thoracic vessels contained Gal-IR but not NPY-IR. Limited observations on sympathetic neurons in two species of wallabies indicated that Gal-IR also was more common than NPY-IR in other marsupial species, but the incidence of NPY-IR was higher in these wallabies than in the brush-tailed possum. Together with previous studies, this work suggests that the coexistence of galanin and NPY may be the primitive condition for sympathetic neurons in tetrapods. The differential expression of these peptides in specific populations of sympathetic neurons may have important functional consequences in the autonomic control of the circulation.     

Neuropeptide Y-immunoreactive neuronal system and colocalization with FMRFamide in the optic lobe and peduncle complex of the octopus (Octopus vulgaris)

The distribution of neuropeptide Y (NPY)-like immunoreactivity and its colocalization with FMRFamide were investigated in the optic lobe and peduncle complex of the octopus ( Octopus vulgaris) by using immunohistochemical techniques. In the optic lobe cortex, NPY-immunoreactive (NPY-IR) fibers were observed in the plexiform layer, although no NPY-IR somata were observed in the outer or inner granular cell layers. In the optic lobe medulla, NPY-IR somata were seen in the cell islands, and abundant NPY-IR varicose fibers were observed in the neuropil. Most of the NPY-IR structures in the medulla showed FMRFamide-like immunoreactivity. In the peduncle lobe, abundant NPY-IR and FMRFamide-IR (NPY/FMRF-IR) varicose fibers were seen in the basal zone neuropil of the peduncle lobe. In the olfactory lobe, NPY/FMRF-IR varicose fibers were also abundant in the neuropil of the three lobules. NPY/FMRF-IR somata, with processes running to various neuropils, were scattered in the median and posterior lobules. In the optic gland, many NPY/FMRF-IR varicose fibers formed a honeycomb pattern. These observations suggest that NPY/FMRF-IR neurons in the optic lobes participate in the modulation of visual information and that those in the optic gland are involved in the regulation of endocrine function.     

Distribution of neuropeptide Y Y1 and Y2 receptors in the postmortem human heart

In the present study, we present for the first time the presence and distribution of neuropeptide Y (NPY) receptors Y1 and Y2 in the human postmortem heart using specific antibodies raised against extracellular parts of the receptors. A more intensive staining against the Y2 than against the Y1 receptors was detected on both atrial and ventricular cardiomyocytes. Immunoreactivity against both receptors was identified on both conducting fibers and cardiac nerves. More vessels stained positively for the Y2 than for the Y1 receptor, but the Y1 receptors were more abundant in subendocardial than subepicardial vessels of the left ventricular wall.     

Myosin types and fiber types in cardiac muscle. II. Atrial myocardium

Antibodies were produced against myosins isolated from the left atrial myocardium (anti-bAm) and the left ventricular myocardium (anti-bVm) of the bovine heart. Cross-reactive antibodies were removed by cross-absorption. Absorbed anti-bAm and anti-bVm were specific for the myosin heavy chains when tested by enzyme immunoassay combined with SDS gel electrophoresis. Indirect immunofluorescence was used to determine the reactivity of atrial muscle fibers to the two antibodies. Three populations of atrial muscle fibers were distinguished in the bovine heart: (a) fibers reactive with anti-bAm and unreactive with anti-bVm, like most fibers in the left atrium; (b) fibers reactive with both antibodies, especially numerous in the right atrium; (c) fibers reactive with anti-bVm and unreactive with anti-bAm, present only in the interatrial septum and in specific regions of the right atrium, such as the crista terminalis. These findings can be accounted for by postulating the existence of two distinct types of atrial myosin heavy chains, one of which is antigenically related to ventricular myosin. The tendency for fibers labeled by anti-bVm to occur frequently in bundles and their preferential distribution in the crista terminalis, namely along one of the main conduction pathways between the sinus node and the atrioventricular node, and in the interatrial septum, where different internodal tracts are known to converge, suggests that these fibers may be specialized for faster conduction.     

Specific distribution pattern of nerve fibers containing catecholamine-synthesizing enzymes, neuropeptide Y (NPY) and C-terminal flanking peptide of NPY (CPON) in the pineal gland of the chinchilla (Chinchilla laniger)--an immunohistochemical study

The sympathetic nerve fibers originating from the superior cervical ganglia and supplying the pineal gland play the most important role in the control of the pineal activity in mammals. NPY and CPON are also present in the majority of the pinealopetal sympathetic neurons. In this study, immunohistochemical techniques were used to demonstrate the existence and coexistence of tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH) as well as NPY and CPON in the nerve fibers supplying the chinchilla pineal gland. Ten two-year-old female chinchillas housed in natural light conditions were used in the study. The pineals were fixed by perfusion. ABC immunohistochemical technique and immunofluorescence labelling method were employed. TH-immunoreactive (TH-IR) varicose nerve fibers were observed in the pineal gland as well as in the posterior commissural area. Within the chinchilla pineal gland, TH-IR nerve fibers were located in the capsule and connective tissue septa. Numerous varicose TH-IR branches penetrated into the parenchyma and formed a network showing the highest density in the proximal region of the gland. In the central and distal parts of the pineal parenchyma, a subtle network, composed of thin varicose nerve branches, was observed. Double immunostaining revealed that the majority of TH-IR nerve fibers was positive for DbetaH or NPY. TH- and DbetaH-positive neuron-like cells were observed in the proximal region of the gland. The pattern of pineal innervation immunoreactive to CPON was similar to the innervation containing NPY, TH and DbetaH. The chinchilla intrapineal innervation containing TH, DbetaH, NPY and CPON is characterized by the higher density in the proximal part of the gland than in the middle and distal ones. The specific feature of the chinchilla pineal is also the presence of single TH/DbetaH-immunoreactive neuron-like cells in the proximal part of the gland.     

Complete sciatic nerve transection induces increase of neuropeptide Y-like immunoreactivity in primary sensory neurons and spinal cord of frogs

Neuropeptide Y (NPY) was immunohistochemically investigated in the frog spinal cord and dorsal root ganglia after axotomy. In normal ganglia, moderate NPY-like immunoreactivity (NPY-IR) prevailed in large and medium cells. In the spinal cord, the NPY-IR was densest in the dorsal part of the lateral funiculus. Other fibers and neurons NPY-IR were observed in the dorsal and ventral terminal fields and mediolateral band. NPY-IR fibers were also found in the ventral horn and in the ventral and lateral funiculi. The sciatic nerve transection increased the NPY-IR in large and medium neurons of the ipsilateral and contralateral dorsal root ganglia at 3 and 7 days, but no clear change was found at 15 days. In the spinal cord, there was a bilateral increase in the NPY-IR of the dorsal part of the lateral funiculus. In the ipsilateral side, the NPY-IR was increased at 3 and 7 days but was decreased at 15 days. In the contralateral side, a significant reduction at 15 days occurred. These findings seem to favor the role of NPY in the modulation of pain-related information in frogs, suggesting that this role of NPY may have appeared early in vertebrate evolution.     

Localization of cholinergic innervation and neurturin receptors in adult mouse heart and expression of the neurturin gene

Neurturin (NRTN) is a neurotrophic factor required during development for normal cholinergic innervation of the heart, but whether NRTN continues to function in the adult heart is unknown. We have therefore evaluated NRTN expression in adult mouse heart and the association of NRTN receptors with intracardiac cholinergic neurons and nerve fibers. Mapping the regional distribution and density of cholinergic nerves in mouse heart was an integral part of this goal. Analysis of RNA from adult C57BL/6 mouse hearts demonstrated NRTN expression in atrial and ventricular tissue. Virtually all neurons in the cardiac parasympathetic ganglia exhibited the cholinergic phenotype, and over 90% of these cells contained both components of the NRTN receptor, Ret tyrosine kinase and GDNF family receptor α2 (GFRα2). Cholinergic nerve fibers, identified by labeling for the high affinity choline transporter, were abundant in the sinus and atrioventricular nodes, ventricular conducting system, interatrial septum, and much of the right atrium, but less abundant in the left atrium. The right ventricular myocardium contained a low density of cholinergic nerves, which were sparse in other regions of the working ventricular myocardium. Some cholinergic nerves were also associated with coronary vessels. GFRα2 was present in most cholinergic nerve fibers and in Schwann cells and their processes throughout the heart. Some cholinergic nerve fibers, such as those in the sinus node, also exhibited Ret immunoreactivity. These findings provide the first detailed mapping of cholinergic nerves in mouse heart and suggest that the neurotrophic influence of NRTN on cardiac cholinergic innervation continues in mature animals.This study was supported by the National Heart, Lung, and Blood Institute (grant HL-54633).     

神经肽Y免疫反应神经和细胞在大鼠颌下腺的分布

本研究应用免疫组织化学ＡＢＣ技术,观察了含神经肽Ｙ神经和细胞在大鼠颌下腺内的分布特点。结果显示：含神经肽Ｙ神经纤维主要走行于腺泡、导管及血管周围。颌下腺内神经节细胞和颗粒曲管细胞亦呈神经肽Ｙ免疫反应阳性。提示：大鼠颌下腺的腺体分泌和血液供应可能受神经肽Ｙ能神经调控。     

Neuropeptide Y: presence in perivascular noradrenergic neurons and vasoconstrictor effects on skeletal muscle blood vessels in experimental animals and man

The presence of neuropeptide Y (NPY)-like immunoreactivity (-LI) in sympathetic perivascular nerves and the functional effects of NPY and noradrenaline (NA) on vascular tone were studied in skeletal muscle of various species. A dense network of NPY-LI was found around arteries and arterioles but not venules in the gluteus maximus muscle of man, gracilis muscle of dog, tenuissimus muscle of rabbit and quadriceps muscle of cat, rat, guinea pig and pig. The distribution of NPY-immunoreactive (-IR) nerves was closely correlated to the presence of tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH)-positive fibers, two markers for noradrenergic neurons. Double-staining experiments revealed that NPY- and TH-IR as well as NPY- and DBH-IR nerve fibers around arteries and arterioles were identical. The veins and venules, however, lacked or had a very sparse innervation of NPY-, TH- and DBH-positive fibers. The NPY- and TH-IR nerves in quadriceps muscle of the guinea pig were absent after treatment with 6-hydroxydopamine. Lumbosacral sympathetic ganglia from the same species contained many NPY-positive cells which were also TH- and DBH-IR. NPY-LI was also detected by radioimmunoassay in extracts of skeletal muscle from guinea pig, rabbit, dog, pig and man as well as of lumbosacral sympathetic ganglia. The content of NPY-LI in skeletal muscle was relatively low (0.1-0.4 pmol/g), whereas lumbosacral sympathetic ganglia had a much higher content (48-88 pmol/g). NPY (10(-7) M) contracted arterioles in the tenuissimus muscle of the rabbit to a similar extent (by 65%) as NA (10(-6) M), as studied by intravital microscopy in vivo. NPY had no effect on the corresponding venules while NA caused a slight contraction of these vessels. In vitro studies of small human skeletal muscle arteries and veins revealed that NPY was more potent than NA in contracting the arteries, and the highest concentration of NPY (5 x 10(-7) M) caused a contraction of a similar magnitude as NA 10(-5) M. NA contracted veins from human skeletal muscle, while NPY had only small effects. It is suggested that NPY, together with NA, could be of importance for sympathetic control of skeletal muscle blood flow.     

Neuropeptide Y-, substance P- and VIP-immunoreactive nerves in cat spleen in relation to autonomic vascular and volume control

Summary Neuropeptide Y (NPY)-immunoreactive (IR) nerve fibres were found around both arteries and veins and in smooth muscle trabeculae of the cat spleen with the highest density on the arterial side. Considerably more tyrosine hydroxylase (TH)- and dopamine--hydroxylase (DBH)-positive than NPY-IR nerves were seen in the trabeculae and splenic capsule. The NPY-IR nerves in the spleen most likely originated in the coeliac ganglion, since (1) splanchnic nerve sectioning did not change the splenic NPY-IR nerves, (2) most neurones in the coeliac ganglion were NPY-IR, as well as DBH- and TH-positive, and (3) NPY-IR was transported axonally from the coeliac ganglion towards the spleen via the splenic nerve. Local NPY infusion in the isolated, blood-perfused cat spleen caused a marked increase in splenic vascular resistance and a small volume reduction. NA caused a comparatively larger reduction in splenic volume than NPY in addition to vasoconstriction. VIP-IR cell bodies in the coeliac ganglion were NPY- and TH-negative. VIP-IR nerves were seen both around the splenic artery and vein as well as around arterioles and within venous trabeculae of the spleen. VIP infusion caused reduction of splenic perfusion pressure (i.e. vasodilation) as well as an increase in splenic volume. Substance P-IR nerves, most likely of splanchnic afferent origin, were present in the coeliac ganglion around the splenic artery and arterioles of the spleen. Infusion of substance P induced marked reduction in perfusion pressure and a reduction in splenic volume. Enkephalin-immunoreactive nerves of splanchnic origin surrounded some TH- and NPY-positive, coeliac ganglion cells.It is concluded that several vasoactive peptides are located in splenic nerves. NPY is present in noradrenergic neurones and causes mainly increased vascular resistance. VIP occurs in non-adrenergic neurones of sympathetic origin and induces vasodilation and relaxation of the capsule. Finally, substance P is present in peripheral branches of spinal afferent nerves and causes vasodilation and capsule contraction. Stimulation of the splenic nerves may thus release several vasoactive substances in addition to noradrenaline, exerting a variety of actions.     

Cholinergic stimulation of neuropeptide Y secretion from the isolated perfused rat stomach.

Neuropeptide Y (NPY) is present in both extrinsic sympathetic adrenergic nerve terminals and intrinsic nerves of the gastrointestinal (GI) tract. Based on this localization a number of functions have been attributed to GI NPY including regulation of blood flow, intestinal fluid and electrolyte transport, and motility. There is nothing currently known, however, about the regulation of its secretion from GI nerves. The effect of cholinergic agonists and antagonists on secretion of NPY immunoreactivity (NPY-IR) from the isolated perfused rat stomach was investigated in the present study. Perfusate samples were extracted and concentrated on SepPak cartridges. Basal levels of NPY-IR varied between 98 and 147 fmol/min. Release was stimulated by high potassium concentrations (50 mM) and acetylcholine (ACh; 1 microM). ACh-induced secretion was unaffected by atropine, but inhibited by hexamethonium. Further evidence for a nicotinic component in the regulation of NPY-IR secretion was obtained by the finding of hexamethonium-induced reduction in basal secretion and stimulation of secretion by 1,1-dimethyl-4-phenyl-piperazinium (DMPP). In conclusion, cholinergic agonists and antagonists can modulate gastric NPY-IR secretion, and the cholinergic stimulatory effects are probably mediated via nicotinic receptor stimulation at the level of the intrinsic ganglia.     

Increases in NPY in non-sympathetic nerve fibres supplying rat mesenteric vessels after immunosympathectomy.

The effect of nerve growth factor (NGF) deprivation on developing peripheral peptide-containing nerves has been examined in Wistar rats. Animals were treated from birth for 7 days with antibodies to NGF (10 microliters/g body weight) and killed at 4 or 8 weeks of age. The nerves of the mesenteric and femoral blood vessels, vas deferns and bladder were viewed with histochemical and immunohistochemical techniques. The effectiveness of anti-NGF treatment was monitored by viewing catecholamine (CA)-containing nerves, which were virtually absent from the blood vessels, but were little affected in the vas deferens and bladder in both age groups. Immunoreactivity for substance P and calcitonin gene-related peptide was slightly reduced in the blood vessels. Immunoreactivity for neuropeptide Y (NPY) was reduced in the femoral blood vessels by 88% at both ages, but reductions in NPY immunoreactivity (NPY-IR) in the mesenteric vessels varied with age. In the mesenteric artery at 4 weeks, NPY-IR was reduced by 96% from control values, but at 8 weeks it was reduced by only 37%. Acute sympathectomy with 6-OHDA treatment reduced NPY-IR in the mesenteric artery by 98% at 4 weeks and 93% at 8 weeks. It is proposed that the increase in NPY-IR but not CA-containing nerves in the mesenteric artery between 4 and 8 weeks after immunosympathectomy is due to compensatory innervation from a non-sympathetic source (probably enteric neurons) that is available to mesenteric, but not to femoral blood vessels.     

Existence and coexistence of peptides in nerves of the mammalian ovary and oviduct demonstrated by immunocytochemistry

The immunocytochemical distribution of substance P (SP), gastrin releasing peptide (GRP), vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine (PHI), and neuropeptide Y (NPY) was studied in the ovary and the Fallopian tube (oviduct) of rats, guinea-pigs, cows, pigs and humans. Generally, the nerve supply was better developed in the oviduct than in the ovary. GRP fibers were most scarce in all tissues. Nerves containing SP were particularly numerous in the oviduct of rat and guinea-pig, supplying the muscular wall and blood vessels. VIP and PHI coexisted in dense plexuses of nerves, not only around blood vessels but also in the follicular wall and the interstitial gland of the ovary, as well as within the smooth muscle layers and subepithelially in the oviduct. The general distribution of NPY was similar, but these immunoreactive nerves were even more numerous. Sequential staining for dopamine-beta-hydroxylase and NPY together with results of chemical sympathectomy with 6-hydroxydopamine suggested that NPY was stored in the noradrenergic sympathetic nerves.     

Immunohistochemical identification of pancreatic hormones,neuropeptides and cytoskeletal proteins in pancreas of the camel (Camelus dromedarius)

The patterns of distribution of insulin (INS), glucagon (GLU), atrial natriuretic peptide (ANP), neuropeptide-Y (NPY), cholecystokinin-octapeptide (CCK-8), neurofilament-200 protein (NF), S-100 protein (S-100), and vimentin (VIM) in the pancreas of the one-humped camel (Camelus dromedarius) were investigated using immunohistochemical techniques. INS-immunoreactive cells were observed in the central and peripheral parts of the islets of Langerhans, but some solitary INS-positive cells were found outside the islets. INS-positive cells constituted 44.26–90.91% [mean ± standard deviation (std): 67.34 ± 14.20] of the total number of islet cells. GLU-immunopositive cells were located mainly in the peripheral region of the islets, and they constituted 11.43–44.44% [mean ± std: 23.54 ± 8.27] of the total number of islet cells. ANP and CCK-8 immunoreactivity was observed in neurons and perivascular nerves fibers. NPY was identified in pancreatic neurons and in some peripheral and central cells of the islets of Langerhans. VIM immunoreactivity was observed in the endothelial cells of blood vessels and the nerves located in the perivascular, interlobular and periacinar regions. VIM was also detected immunohistochemically in the periductal nerves of the pancreas. NF occurred only in nerves. S-100 was discerned mainly in the nerves of the interlobular connective tissue and in nerves lying close to blood vessels and acinar tissue. It is concluded that INS, GLU, ANP, NPY, CCK-8, NF, S-100, and VIM are well distributed in the pancreas of the camel. J. Morphol. 231:185–193, 1997. © 1997 Wiley-Liss, Inc.