Light, fluorescence and electron microscopic studies of rabbit subclavian glomera.

The subclavian glomera (aortic bodies) of young New Zealand white rabbits were studied with the light, fluorescence, and electron microscopes. Two cell types were identified: type I, granule-containing (chief) cells, and type II, agranular (sustentacular) cells. The type I cells possessed large nuclei, the normal complement of cytoplasmic organelles and numerous electron-opaque cytoplasmic granules. The type II cells were agranular with attenuated cytoplasmic processes which partially or completely ensheathed the type I cells. The glomera were well vascularized. Capillary endothelial cells contained numerous pinocytotic vesicles, but few fenestrae. Two profiles of nerve terminals were observed. One, apposing the type I cells, contained numerous electron-lucent vesicles, several dense-cored vesicles, mitochondria and possessed membrane specializations resembling those usually observed in synaptic zones. The other profile contained abundant mitochondria and a few electron-lucent and dense-cored vesicles. Structural specializations were not observed on the apposed membranes of these terminals or adjacent to type II cells. Fluorescence histochemistry revealed an intense yellow-green fluorescence in the glomera, which indicated the presence of biogenic amines, possibly primary catecholamines or an indolamine. The electron-opaque granules observed in the type I cells were believed to be the storage sites for these amines. The subclavian glomera were found to be morphologically similar to the carotid body which is a known chemoreceptor.     

A possible balance of calcium accumulations among bone, cartilage, artery, and vein in single human individuals

To elucidate the relationships between the decrease of mineral contents in human bones and the accumulation of minerals in the other human tissues, the relative contents (RCs) of calcium were analyzed by inductively coupled plasma atomic emission spectrometry among human bones, arteries, veins, and cartilages in 27 subjects (17 men and 10 women). These were resected from subjects who died in the age range from 40 to 98 yr old. Calcanei were chosen for analysis of mineral contents in contrast with femoral, popliteal and common carotid arteries, internal jugular veins, and pubic symphysis. It was found that the RCs of calcium in calcanei were agreeable to association with those in both the pubic symphysis and the femoral artery, but they were not agreeable to association with those in the popliteal and common carotid arteries, and the internal jugular veins. This suggests that calcium released from bones is accompanied by accumulations of calcium in the artery and cartilage.     

Effect of various types of sports on the anatomy of the common carotid artery and the internal jugular vein

By means of ultrasonography the common carotid artery and the internal jugular vein at certain sports have been investigated. In swimmers the internal jugular vein is essentially dilated as compared to the common carotid artery. In high jumpers there is not any noticeable differences between the width of the artery and the vein. These data should be taken into account at training sportsmen. They are also important for development of investigations in the ultrasound anatomy.     

Distribution and origin of vasoactive intestinal polypeptide (VIP)-immunoreactive,acetylcholinesterase-positive and adrenergic nerves of the cerebral arteries in the bent-winged bat (Mammalia: Chiroptera)

Summary The overall distribution and origins of vasoactive intestinal polypeptide (VIP)-immunoreactive (IR), acetylcholinesterase (AChE)-positive and adrenergic nerves in the walls of the cerebral arteries were investigated in the bent-winged bat. VIP-IR and AChE-positive nerves innervating the bat cerebral vasculature appear to arise mainly from VIP-IR and AChE-positive cell bodies within microganglia found in the nerve bundle accompanying the sympathetic nerve bundle within the tympanic cavity. These microganglia, as well as the nerve bundle containing them, do not emit catecholamine fluorescence, suggesting that they are of the cranial parasympathetic outflow, probably the facial or glossopharyngeal one. The axons from VIP-IR and AChE-positive microganglia run intermingled with sympathetic adrenergic nerves in the same thick fiber bundles, and reach the cranial cavity through the carotid canal. In addition, some of the VIP-IR fibers innervating the vertebro-basilar system, at least the basilar artery, originate from VIP-IR nerve cells located in the wall of this artery.The supply of VIP-IR fibers to the bat major cerebral arteries is the richest among mammals that have been studied, and differs from other mammals in that it is much greater in the vertebro-basilar system than in the internal carotid system: plexuses of VIP-IR nerves are particularly dense along the walls from the posterior ramus to posterior cerebral and basilar arteries. Small pial and intracerebral arteries of the vertebro-basilar system, especially those of the posterior cerebral artery which supply most parts of the diencephalon and cerebrum, are also richly innervated by peripheral VIP-IR fibers. This pattern corresponds well with the innervation pattern of adrenergic and AChE-positive nerves.     

A possible balance of phosphorus accumulations among bone, cartilage, artery, and vein in single human individuals

To elucidate relationships between the decrease of mineral contents in human bones and the accumulation of minerals in the other human tissues, the contents of phosphorus in human bones, arteries, veins, and cartilages in 27 subjects (17 men and 10 women) were analyzed by inductively coupled plasma-atomic emission spectrometry. These were resected from subjects who died in the age range 40–98 yr. Calcanei were chosen for analysis of mineral contents in contrast to arteries such as the femoral, popliteal, and common carotid arteries, veins such as superior and inferior venae cavae, internal jugular, and femoral veins, and pubic symphyses. It was found that the content of phosphorus in calcanei was in agreement with that in both the pubic symphysis and the arteries such as femoral, popliteal, and common carotid arteries, but it was not in agreement with that in the veins such as superior and inferior venae cavae, internal jugular, and femoral veins. This suggests that phosphorus released from bones is accompanied by accumulations of phosphorus in the artery and cartilage.     

Lamellar bodies at the cell periphery of human muscle fibers

The cytochemical and ultrastructural features of lamellar bodies in human skeletal muscle fibers were studied using tannic acid-glutaraldehyde, ruthenium red-glutaraldehyde fixation methods, conventional electron microscopy and the freeze fracture technique. The lamellar bodies consisted of concentric lamellae with a regular spacing of 6.5 +/- 0.2 nm. These structures were found preferentially at the cell periphery closely associated with the plasma membrane, near the nuclear poles and in the space between muscle fiber and satellite cell. The cytochemical and ultrastructural features of the lamellar bodies suggest they are largely composed of phospholipid. It is possible that these structures are involved in muscle membrane maintenance.     

Nitric oxide synthase-containing neurons in rat parasympathetic, sympathetic and sensory ganglia: a comparative study

Summary In rats, the distribution of nerve structures staining for NADPH-diaphorase, and showing immunoreactivities for nitric oxide synthase (NOS), tyrosine hydroxylase and various neuropeptides was studied in sensory ganglia (dorsal root, nodose and trigeminal ganglia), in sympathetic ganglia (superior cervical, stellate, coeliac-superior and inferior mesenteric ganglia), parasympathetic ganglia (sphenopalatine, submandibular, sublingual and otic ganglia), and in the mixed parasympathetic/ sympathetic ganglia (major pelvic ganglia). The coincidence of neuronal cell bodies with strong NOS-immunoreactivity and strong NADPH diaphorase reactivity was almost total. The relative proportions of NOS-immunoreactive nerve cell bodies were largest in parasympathetic ganglia and major pelvic ganglia followed by sensory ganglia. In sympathetic ganglia no NOS-immunoreactive neuronal cell bodies could be detected. In parasympathetic and major pelvic ganglia, there was a very significant neuronal co-localization of immunoreactivities for NOS and vasoactive intestinal polypeptide (VIP). This was almost total in major pelvic ganglia, in which NOS-/VIP-immunoreactive nerve cell bodies were separate from sympathetic (tyrosine hydroxylase-/neuropeptide Y-immunoreactive), suggesting that NOS-/VIP-immuno-reactive neurons might also be parasympathetic.     

Feeding state influences the content of FMRFamide- and tachykinin-related peptides in endocrine-like cells of the midgut of Locusta migratoria

The midgut of 5th instar male African migratory locust, Locusta migratoria, was found to contain endocrine-like cells that stained positively for FMRFamide-like immunoreactivity. These cells have cell bodies which are tear-drop in shape with processes extending from the cell body. FMRFamide-like immunoreactivity has been described in similar cells in adult midgut tissue [16]. The midgut tissue content of FMRFamide-like immunoreactivity is differentially distributed throughout various regions of the midgut (gastric cecae, anterior and posterior midgut) in 5th instar and varied ages of adult. FMRFamide-like immunoreactivity in midgut tissues decreases significantly by 24 h of starvation, whereas locustatachykinin I-like immunoreactivity does not decrease until 48 h of starvation indicating that there are differential timing effects of these two peptide families on midgut content. HPLC analysis, combined with RIA, of different regions of the midgut tissue from both fed and starved locusts revealed that the relative proportions of the members of the two peptide families vary depending upon the feeding state. These results indicate that the contents of these endocrine-like cells appears to be differentially influenced by the feeding state of the locust.     

Possible “atavistic” structures in human aneuploids

Comprehensive dissections of aneuploid (trisomy 18 and 13) neonates have revealed numerous supernumerary muscles that, although present in rare individuals, do not regularly occur in the human. These supernumerary muscles include: “platysma occipitalis,” “rhomboideus occipitalis,” “deltopectoral” complex, “latissimocondyloideus,” “pectorodorsalis,” “chondrohumeralis,” and “peroneus digiti quinti”; a few muscles, e.g., palmaris longus and brevis are lacking altogether. One specimen exhibited a “linguofacial trunk” arising from the external carotid artery. The supernumerary muscles found in these aneuploid specimens are regularly found in monkeys and sometimes in the great apes. It is suggested that these supernumerary muscles may be “atavistic” structures. Problems in establishing homologies between these muscles among primates are discussed, and mechanisms leading to the development of these muscles in human aneuploids are proposed.     

Comparison of nonenzymatic glycosylation of arterial and venous collagens

The extent of nonenzymatic glycosylation of collagen isolated from sheep carotid arteries and jugular veins was compared. It was found that the level of this modification in the arterial collagen was about 2.7 times higher than that in the venous collagen. Arteriovenous fistulae were established between the common carotid artery and external jugular vein on one side only of six sheep. Sham arteriotomy and phlebotomy were performed on the contralateral vessels. Although there was an increase in the concentration of these ketoamine-linked hexoses in all the tissue samples assayed, a difference of between two- and three-fold was maintained between the arterial and venous tissue. The relationship of this finding to the development of vascular complications and to the level of circulating reducing sugar is discussed.     

Intranuclear ubiquitin-immunopositive structures in human substantia nigra neurons

Marinesco bodies were discovered in substantia nigra neurons of human brain in 1902. The relationships between these intranuclear inclusions and the other structures of the cellular nucleus are still obscure. The aim of this study is to elucidate the morphological and cytochemical peculiarities of intranuclear ubiquitin-immunopositive bodies in the substantia nigra neurons of human brain and to evaluate the interconnections of these peculiarities with nucleolus by means of light microscopy, immunocytochemistry, and confocal laser microscopy. It is found that up to 20% of neurons in substantia nigra of human brain contain ubiquitin-immunopositive Marinesco bodies. These rounded structures are 1–8 μm—more often 2–4 μm—in diameter. Only one-third of them are tightly adjacent to the nucleolus. By a method of silver impregnation of argentophilic proteins associated with nucleolar organizer, the absence was shown of argentophilic proteins, which are characteristic for the nucleolus, in Marinesco bodies. Special ubiquitin-positive substantially smaller structures (less than 1 μm) are revealed in the neurons’ nuclei along with Marinesco bodies. These structures are probably the initial forms in the formation of Marinesco bodies. The existence of two types of ubiquitin-immunopositive intranuclear bodies is revealed by means of confocal microscopy: one has high intensity of immunofluorescence, and the other has low intensity. Heterogeneous distribution of immunopositive product is characteristic of the former. The presence of DNA in Marinesco bodies is detected by using SYTOX Green fluorescent dye. The absence of peripheral heterochromatin zone and weak susceptibility to toluidine blue together with the presence of DNA and the absence of argentophilic proteins suggests substantial structural and chemical differences between Marinesco bodies and nucleoli, which argues against the idea that the detected bodies are modified nucleoli.     

Experimental use of free gastric flaps for the repair of pharyngoesophageal defects.

The repair of large pharyngoesophageal defects was accomplished experimentally in 16 dogs with revascularized free flaps from the greater curvature of the stomach. These flaps were based on the gastroepiploic vessels, and they were anastomosed to the carotid artery and external jugular vein in the neck. The procedure had a low mortality and did not lead to peptic ulceration or hyperchlorhydria in these animals.     

Light and electron microscopic observations on the carotid bodies of rats following adaptation to high altitude.

The carotid bodies of rats were investigated by light and electron microscopy following adaptation to a simulated altitude of 7000 m. Some animals were studied immediately after readaptation to sea-level, other groups up to 41 days later. The animals of the first group show enlarged glomera with dilated capillaries as reported earlier.The type-I-cells are large with a light staining cytoplasm. The lobular configuration of the glomus is lost and intracapillary platelet thrombosis are frequently found. Under these thrombi there is usually a chief cell degeneration with edema and vacuolisation. There is also a noticeable decrease in so-called catecholamine bodies and the remaining ones are usually arranged along the cell borders. Electron microscopically the intercapillary tissue reveals an increase in collagen material partially replanning lost chief cells. Essentially unaltered sustentacular cells frequently enclose with their processes only collagen bundles and nerve fibres. During 41 days following the readaptation there is a narrowing of capillaries and vacuolisation, swelling and thromboses are no longer observed. The amount of collagen, however, remains the same. Dense cored vesicles again increase in number and the chief cells show a prominent interdigitation. Light microscopically the restoration to normal appears to be almost complete. Fine structural analysis, however, shows an appearently permanent distortion in the composition and cellular arrangement of the glomus.     

Signal processing at mammalian carotid body chemoreceptors

Mammalian carotid bodies are richly vascularized chemosensory organs that sense blood levels of O₂, CO₂/H⁺, and glucose and maintain homeostatic regulation of these levels via the reflex control of ventilation. Carotid bodies consist of innervated clusters of type I (or glomus) cells in intimate association with glial-like type II cells. Carotid bodies make afferent connections with fibers from sensory neurons in the petrosal ganglia and receive efferent inhibitory innervation from parasympathetic neurons located in the carotid sinus and glossopharyngeal nerves. There are synapses between type I (chemosensory) cells and petrosal afferent terminals, as well as between neighboring type I cells. There is a broad array of neurotransmitters and neuromodulators and their ionotropic and metabotropic receptors in the carotid body. This allows for complex processing of sensory stimuli (e.g., hypoxia and acid hypercapnia) involving both autocrine and paracrine signaling pathways. This review summarizes and evaluates current knowledge of these pathways and presents an integrated working model on information processing in carotid bodies. Included in this model is a novel hypothesis for a potential role of type II cells as an amplifier for the release of a key excitatory carotid body neurotransmitter, ATP, via P2Y purinoceptors and pannexin-1 channels.     

VIP-, galanin-, and neuropeptide-Y-immunoreactive fibers in the chicken carotid bodies after various types of denervation

The chicken carotid body receives numerous branches from the vagus nerve, especially distal (nodose) ganglion, and the recurrent laryngeal nerve. Dense networks of peptidergic nerve fibers immunoreactive for substance P, calcitonin gene-related peptide (CGRP), galanin, vasoactive intestinal peptide (VIP) and neuropeptide Y are distributed in and around the carotid body. Substance-P- and CGRP-immunoreactive fibers projecting to the chicken carotid body mainly come from the vagal ganglia. In the present study, various types of denervation experiments were performed in order to clarify the origins of VIP-, galanin- and neuropeptide-Y-immunoreactive fibers in the chicken carotid bodies. After nodose ganglionectomy, midcervical vagotomy or excision of the recurrent laryngeal nerve, VIP-, galanin- and neuropeptide-Y-immunoreactive fibers were unchanged in the carotid body region. Furthermore, these peptidergic fibers remained unaffected even by removal of the nodose ganglion in conjunction with severance of the recurrent laryngeal nerve that induced a marked decrease in TuJ1-immunoreactive fibers in the carotid body region. VIP-, galanin- and neuropeptide-Y-immunoreactive fibers are densely distributed around the arteries supplying the carotid body in normal chickens. The peptidergic fibers around the arteries were also unaffected after the denervation experiments. However, after removal of the 14th cervical ganglion of the sympathetic trunk, which lies close to the vertebral artery on the root of the brachial plexus and issues prominent branches to the artery, VIP-, galanin- and neuropeptide-Y-immunoreactive fibers almost disappeared in the carotid body region. The ganglion contained many VIP-, galanin- and neuropeptide-Y-immunoreactive neurons. Thus it is clear that VIP-, galanin- and neuropeptide-Y-immunoreactive fibers in the chicken carotid body region are mainly derived from the 14th cervical sympathetic ganglion via the vertebral artery.     

Taste cell responses in the frog are modulated by parasympathetic efferent nerve fibers

We studied the anatomical properties of parasympathetic postganglionic neurons in the frog tongue and their modulatory effects on taste cell responses. Most of the parasympathetic ganglion cell bodies in the tongue were found in extremely small nerve bundles running near the fungiform papillae, which originate from the lingual branches of the glossopharyngeal (GP) nerve. The density of parasympathetic postganglionic neurons in the tongue was 8000-11,000/mm(3) of the extremely small nerve bundle. The mean major axis of parasympathetic ganglion cell bodies was 21 microm, and the mean length of parasympathetic postganglionic neurons was 1.45 mm. Electrical stimulation at 30 Hz of either the GP nerve or the papillary nerve produced slow hyperpolarizing potentials (HPs) in taste cells. After nicotinic acetyl choline receptors on the parasympathetic ganglion cells in the tongue had been blocked by intravenous (i.v.) injection of D-tubocurarine (1 mg/kg), stimulation of the GP nerve did not induce any slow HPs in taste cells but that of the papillary nerve did. A further i.v. injection of a substance P NK-1 antagonist, L-703,606, blocked the slow HPs induced by the papillary nerve stimulation. This suggests that the parasympathetic postganglionic efferent fibers innervate taste cells and are related to a generation of the slow HPs and that substance P is released from the parasympathetic postganglionic axon terminals. When the resting membrane potential of a taste cell was hyperpolarized by a prolonged slow HP, the gustatory receptor potentials for NaCl and sugar stimuli were enhanced in amplitude, but those for quinine-HCl and acetic acid stimuli remained unchanged. It is concluded that frog taste cell responses are modulated by activities of parasympathetic postganglionic efferent fibers innervating these cells.     

An electron microscopic study on the effects of reserpine on the subclavian glomera of the rabbit.

Young male and female New Zealand white rabbits were given a daily subcutaneous injection of reserpine (Serpasil, Ciba; 3 mg/kg) for two days and were sacrificed 24 hours after the last injection. The subclavian glomera (aortic bodies) were processed for electron microscopy to determine the effects of this biogenic amine depleting agent on the electron-opaque cytoplasmic granules of the parenchymal type I cells. Observations of glutaraldehyde-osmium tetroxide fixed glomera from reserpinized animals showed a slight decrease in granule density of the type I cells. Glomera fixed in glutaraldehyde and incubated in potassium dichromate (pH 4.1) demonstrated a reduction in granule opacity following reserpine treatment. Control glomera incubated in potassium dichromate displayed electron-opaque granules. These results indicate that reserpine does deplete the amines without granule disappearance or changes in granule population. The positive reaction of the control tissue granules to potassium dichromate incubation suggests that the predominant biogenic amines in the electron-opaque granules are unsubstituted monoamines. Persistence of the opaque granules following reserpinization and glutaraldehyde-osmium tetroxide double fixation, may be due to amine-binding protein within the granules. The mode of granule depletion could not be ascertained with certainty.     

KISS1 and KISS1R expression in the human and rat carotid body and superior cervical ganglion

KISS1 and its receptor, KISS1R, have both been found to be expressed in central nervous system, but few data are present in the literature about their distribution in peripheral nervous structures. Thus, the aim of the present study was to investigate, through immunohistochemistry, the expression and distribution of KISS1 and KISS1R in the rat and human carotid bodies and superior cervical ganglia, also with particular reference to the different cellular populations. Materials consisted of carotid bodies and superior cervical ganglia were obtained at autopsy from 10 adult subjects and sampled from 10 adult Sprague-Dawley rats. Immunohistochemistry revealed diffuse expression of KISS1 and KISS1R in type I cells of both human and rat carotid bodies, whereas type II cells were negative. In both human and rat superior cervical ganglia positive anti-KISS1 and -KISS1R immunostainings were also selectively found in ganglion cells, satellite cells being negative. Endothelial cells also showed moderate immunostaining for both KISS1 and KISS1R. The expression of both kisspeptins and kisspeptin receptors in glomic type I cells and sympathetic ganglion cells supports a modulatory role of KISS1 on peripheral chemoreception and sympathetic function. Moreover, local changes in blood flow have been considered to be involved in carotid body chemoreceptor discharge and kisspeptins and kisspeptin receptors have also been found in the endothelial cells. As a consequence, a possible role of kisspeptins in the regulation of carotid body blood flow and, indirectly, in chemoreceptor discharge may also be hypothesized.     

Distribution of vasoactive intestinal polypeptide-like immunoreactivity in the mammalian heart

Summary The distribution of vasoactive intestinal polypeptide (VIP) immunoreactivity has been studied in the mammalian heart and compared with that of neurotensin and substance P by use of light-microscopic peroxidase-antiperoxidase immunohistochemistry. VIP-immunoreactive cell bodies are present in intracardiac ganglia in various locations. VIP-immunoreactive nerve fibers predominate in the atria and the conduction system but are rare in the ventricles and occur in cardiac ganglia, endocardium, and epicardium. VIP-ergic nerves supply the coronary vasculature having a preference for the microvasculature and the nodal cells of the sinuatrial node. The large vessels of the heart and periarterial cardiac glomera also receive a VIP-immunoreactive nerve supply. There is partial co-distribution with neurotensin- and substance P-immunoreactive nerve fibers but no co-location in identical nerve fibers is detectable. The VIP-ergic cardiac innervation, which is probably predominantly intrinsic, may stem from postganglionic parasympathetic neurons and is less substantial than the more homogeneous neurotensin-ergic and substance P-ergic nervous supply which is probably extrinsic. The occurrence of an extrinsic VIP-ergic cardiac innervation cannot be excluded however. The differential histotopography of the multitarget cardiac nerves containing the cardiovascular active peptides VIP, neurotensin and substance P may suggest multiple and complex peptide-peptide and peptide-classical transmitter interactions. These may contribute to the regulation of various cardiac functions.     

Parasympathetic reflex vasodilation in the cerebral hemodynamics of rats

We investigated the role of parasympathetic reflex vasodilation in the regulation of the cerebral hemodynamics, and whether GABA_A receptors modulate the response. We examined the effects of activation of the parasympathetic fibers through trigeminal afferent inputs on blood flow in the internal carotid artery (ICABF) and the cerebral blood vessels (rCBF) in parietal cortex in urethane-anesthetized rats. Electrical stimulation of the central cut end of the lingual nerve (LN) elicited intensity- and frequency-dependent increases in ICABF that were independent of changes in external carotid artery blood flow. Increases in ICABF were elicited by LN stimulation regardless of the presence or absence of sympathetic innervation. The ICABF increases evoked by LN stimulation were almost abolished by the intravenous administration of hexamethonium (10 mg kg^?1) and were reduced significantly by atropine administration (0.1 mg kg^?1). Although the LN stimulation alone had no significant effect on rCBF, LN stimulation in combination with a blocker of the GABA_A receptor pentylenetetrazole increased the rCBF markedly. This increase in rCBF was reduced significantly by the administration of hexamethonium and atropine. These observations indicate that the increases in both ICABF and rCBF are evoked by parasympathetic activation via the trigeminal-mediated reflex. The rCBF increase evoked by LN stimulation is thought to be limited by the GABA_A receptors in the central nervous system. These results suggest that the parasympathetic reflex vasodilation and its modulation mediated by GABA receptors within synaptic transmission in the brainstem are involved in the regulation of the cerebral hemodynamics during trigeminal afferent inputs.