Adrenergic nerves in the corpora cavernosa penis of some mammals

Summary The corpora cavernosa et spongiosa penis from Rhesus monkeys, Cynomolgus monkeys and cats have been investigated by means of the method for fluorescence microscopical detection of catecholamines- and tryptamines according to Falck and Hillarp.In all species investigated the smooth muscle cells surrounding the sinusoidal cavities of the corpora cavernosa are densely innervated by varicose adrenergic nerve fibres, which form a typical autonomic ground-plexus. A superficial and a deep plexus have been distinguished, the former being composed of densely packed preterminal, ramifying bundles the latter consisting mainly of terminal varicose fibres. In contrast to this the corpus spongiosum — being mainly composed of collagenous and elastic tissue — receives only a moderate adrenergic nerve supply related to the small bundles of smooth musculature. Whereas arteries of the penis are characterized by a superficial adventitial fibre plexus, the greater veins of the penis are supplied by adrenergic fibre meshes which penetrate the media up to the limiting lamina elastica interna. In addition the paraurethral glands seem to possess a direct adrenergic innervation.According to microspectrographical results it is concluded that the transmitter is noradrenaline. This assumption is supported by the finding of relatively high amounts of noradrenaline in tissue pieces from the erectile tissue of four Rhesus monkeys: 0,67 g/g (± 0,05). No dopamine or adrenaline have been detected.Scattered along the whole length of the urethral epithelium there occur yellow fluorescent cells morphologically resembling enterochromaffin cells. The fluorophore has the spectral properties of formaldehyde-condensed authentic 5-hydroxytryptamine.The possible role of the sympathetic noradrenergic innervation to the penis concerning the initiation and termination of the erection is discussed.

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Zusammenfassung Die Corpora cavernosa und spongiosa penis von Rhesusaffen (Macaca mulatta), Javaneraffen (Cynomolgus irus = Macaca fascicularis) und Hauskatzen (Felis domestica) wurden mit der von Falck und Hillarp entwickelten Methode zum fluoreszenzmikroskopischen Nachweis von Catechol- und Tryptaminen untersucht.Die glatten Muskelzellen der cavernösen Hohlräume werden von einem dichten Geflecht variköser, adrenerger Nervenfasern innerviert. Das Aufbauprinzip dieses Plexus ähnelt dem des autonomen Grundplexus (Hillarp). Der pericavernöse Plexus läßt sich in einen oberflächlichen Anteil gliedern, der aus gebündelten, präterminalen Nervenfasern besteht und in einen tiefen Plexus, der aus varicositätenreichen Endaufzweigungen aufgebaut ist. Im Gegensatz dazu besitzt das an kollagenen und elastischen Fasern reiche Corpus spongiosum nur eine spärliche Nervenversorgung. Während die Arterien des Penis mit einem adventitiellen adrenergen Plexus ausgestattet sind, werden die Venen von einem adrenergen Fasergeflecht innerviert, das alle Schichten der Adventitia und der Media gleichmäßig durchsetzt. Bei allen untersuchten Spezies kommen außerdem adrenerge Fasern in Begleitung der Paraurethraldrüsen vor.Aus mikrospektrographischen Befunden wird gefolgert, daß die Grünfluoreszenz in den Nervenfasern auf die Anwesenheit von Noradrenalin zurückzuführen ist. Diese Annahme wird durch den Nachweis relativ großer Mengen von Noradrenalin im Schwellkörpergewebe von vier Rhesusaffen bestätigt (0,67 g/g ±0,05). Dopamin und Adrenalin konnten nicht nachgewiesen werden.Zwischen den Epithelzellen der Harnröhrenmukosa kommen einzelne Zellen vor, deren Cytoplasma eine intensiv gelb fluoreszierende Substanz enthält. Das gelb fluoreszierende Produkt besitzt die gleichen spektralen Eigenschaften wie formaldehydkondensiertes 5-Hydroxytryptamin.Die Bedeutung der sympathischen, noradrenergen Innervation für die Einleitung und Beendigung der Erektion des Penis wird diskutiert.

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Dedicated to Prof. Dr. Dr. E. Horstmann with the best wishes for his 60 th birthday.

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Supported by the Deutsche Forschungsgemeinschaft and by grants from the Swedish Medical Research Council/project no. B 69-14X-56-05C and the Ford Foundation, grant no. 68-383.     

Adrenergic innervation of the umbilical vessels

Summary The intra- and extrafetal portions of the umbilical vessels in the guinea-pig and the umbilical cord of man, mouse and rabbit have been investigated by means of the Falck-Hillarp method for the fluorescence microscopical demonstration of catecholamines.The umbilical cord was found to be devoid of nerves in all species investigated. Adrenergic nerves are present only in the immediate vicinity of the umbilicus.The intrafetal portions of the umbilical artery and umbilical vein receive adrenergic nerves, the distribution pattern of which is different for each vessel. In the guinea-pig the ductus venosus is an intrahepatic branch of the vena umbilicalis. No adrenergically innervated sphincter has been detected in the initial segment of the ductus venosus. Regional variations in the pattern of innervation of the intrafetal portion of the umbilical vein are paralleled by regional differences in the construction pattern of the vessel's wall. Regional differences in the noradrenaline concentration (measured by fluorometry) which correspond to the fluorescence microscopical findings have been detected in umbilical vessels: low noradrenaline content of the umbilical cord, high concentrations in the intrafetal sections of the umbilical vessels. The noradrenaline concentration of the guinea-pig umbilical artery is three times that of the umbilical vein.Supported by the Joachim Jungius-Gesellschaft der Wissenschaften, Hamburg.For continuous advice and constructive criticism I am indebted to Prof. Dr. Dr. E. Horstmann.     

Phosphomonoesterases in the male genital system of some mammals.

The various male genital organs of the experimental animals used in this investigation (rat, guinea pig, rabbit, cat and dog) showed a widely different localizations of alkaline and acid phosphatases. Alkaline phosphatase was presented as secretory, stromal, nuclear and vascular, while with acid phosphatase, distinction was made only between secretory and nuclear phosphatases. Although the morphological distributions of both enzymes were sometimes overlapping, they were not identical.     

Proprioceptive innervation of the external cremaster muscle of some domestic mammals.

The proprioceptive innervation of the external cremaster muscle of some domestic animals was studied. Muscle spindles and tendon organs with their well-known features were found, but this finding was uncommon and unexpected in the investigated animals. For this reason, we believe that there is no relationship between the presence of these proprioceptors and the cremasteric reflex.     

Luminescent-histochemical study of the sympathetic innervation of the large intestine in some mammals]

It has been established that specifically fluorescening fibres and their endings as well as neurons along the length of the large intestine and in the thick of its wall have uneven distribution in cats, albino rats and dogs. A considerable part of fibres are concentrated in the muscular-intestinal, submucose plexuses and in the circular muscular layer. The greatest amount of fibres can be found in the rectum wall. They form various synaptic contacts mainly with parasympathetic neurons. Such connections with the bundles of smooth muscles are not very numerous. An exclusion is the rectum because in its wall there are equally many endings of both kinds. Solitary fibres and their endings are referred to the neurons of intramural ganglia. Their amount here is not great, most frequently they are found in cranial portions of the large intestine.     

Adrenergic innervation of the gut musculature in vertebrates

Summary The adrenergic innervation of the gut musculature has been compared in various vertebrates (two teleost fish, an amphibian, a reptile and a mammal) by the fluorescent histochemical localization of certain monoamines. Very few, if any, adrenergic nerves occur within the longitudinal gut muscle of any of these animals, except for the taenia coli of the guinea-pig caecum. In contrast, the circular smooth muscle coat is supplied by varicose adrenergic nerves. These nerve fibres are particularly numerous in the toad large intestine, guinea-pig caecum, and throughout the eel gut, but are generally sparse or absent from the musculature of the stomach and small intestine of the trout, toad, lizard and guinea-pig. The extent of adrenergic innervation of the muscle has been discussed in relation to the physiology of the different muscle coats and to the general structure of the enteric plexuses in the vertebrate gut.     

Adrenergic terminal structures in the mesentery of mammals

This work is devoted to the study of adrenergic terminal structures in the mesentery of mammals (cat, dog). The investigation was performed with the Falck-Hillarp method of catecholamine fluorescence microscopy on total stretch mesentery preparations. The investigation showed that richly developed perivascular plexus constitute the basis of the adrenergic innervation system of the mesentery. In numerous points of these plexuses, single adrenergic fibers or polyaxonal structures are observed to issue into nonvascular areas of the mesentery where after repeated dichotomic division they pass into the preterminal and terminal parts. Being constructed on the principle of extended or restrained arborizations, these innervating structures have a morphological similarity with free sensory nerve endings. In this connection, the question of the possible existence of the sensory (afferent) links in the catecholamine-containing vegetative nerve plexuses is discussed.     

Adrenergic innervation of the human gall bladder

Summary Adrenergic innervation of the human gall bladder was studied using two specific fluorescence histochemical methods. Blue-green fluorescing varicose nerves were scarce and mostly followed the course of blood vessels as typical perivascular plexuses. However, some adrenergic nerves not associated with the vessels were occasionally seen, as well as structures suggestive of a pericellular arrangement of varicose adrenergic nerve terminals on non-fluorescing ganglion cells. A few enterochromaffin cells were seen in the epithelial lining, also in the deep invaginations obviously representing the Aschoff-Rokitansky sinuses. Occasionally, small rounded cells with a rounded, relatively large nucleus, and exhibiting a weak yellow-green to blue-green granular cytoplasmic fluorescence, were observed in the wall of the gall bladder. The possible functional and evolutionary significance of these neural and endocrine elements was discussed against the data on physiological and pharmacological studies obtained from the literature. It was concluded that their significance is, in all probability, secondary to the influence of the intestinal polypeptide hormones, vagal innervation and circulating catecholamines upon the normal function of the gall bladder. The glyoxylic acid-induced fluorescence histochemical method was found to be superior to the conventional formaldehyde technique in studies on human tissue.     

Adrenergic innervation of the salivary glands in the rat

Summary The adrenergic innervation of the major salivary glands in the rat has been studied by a specific histochemical method for the visualization of the adrenergic transmitter. Adrenergic varicose nerve fibres were found, located in a typical adrenergic ground plexus closely surrounding the serous acini of the submaxillary and parotid glands, but not the acini of the mainly mucous sublingual gland. The ducts were found to be completely devoid of adrenergic innervation. Arterioles and venules in the stroma of all three glands and certain very small vessels, possibly the sphincters of arterio-venous anastomoses, were also richly innervated by adrenergic vasomotor fibres. The relationship of the adrenergic nerve fibres to the different functional units of the gland parenchyma is discussed.The investigation has been supported by a research grant (B 66–257) from the Swedish Medical Research Council and by a Public Health Service Research Grant (NB 05236-01) from the National Institute of Neurological Diseases and Blindness.