ALBERT

Notes: Summary The distribution of monoamines in the pharynx and oesophagus of the rhesus monkey (Macacus rhesus) and the cat (Felis domestica) was investigated by means of fluorescence microscopical and chemical methods. Fluorimetric determinations reveal the presence of varying amounts of noradrenaline in the pharynx and oesophagus of the rhesus monkey. The lowest amount (0.05 (μg/g) was found in the lower part of the oesophagus, the so-called sphincter-segment. The middle and upper part of the oesophagus contain medium amounts of noradrenaline (0.06–0.09 μg) whereas the highest concentration was detected in the pharynx (0.14 (μg/g). Neither dopamine nor adrenaline occurred in the tissue pieces analyzed. Fluorescence microscopically noradrenaline was found to be located in varicose intramural nerve fibre plexus which innervate mucous glands and blood vessels in the pharynx of both species. In the rhesus monkey, the lamina muscularis mucosae of all parts of the oesophagus is supplied by a well developed noradrenergic ground-plexus. Preterminal and terminal varicose nerve fibres are distributed in myenteric and submucous ganglia of the oesophagus; the number of such ganglia decreases towards the lower segment. The density of the adrenergic innervation is higher in myenteric when compared to submucous ganglia. The arrangement of the intraganglionic terminals suggests that both axosomatic and axodendritic contacts occur in Auerbach's ganglia whereas axodendritic contacts seem to predominate in Meissner's ganglia. Myenteric ganglia situated close to the submucosa as well as true submucous ganglia may be occasionally seen to be traversed by faintly fluorescent non-varicosed fibres which do not establish any synaptic contacts. The fluorescence intensity of intraganglionic varicosities varies considerably; accordingly the transmitter content of individual varicosities seems to be very variable. The adrenergic innervation of the lamina muscularis is restricted to single contorted fibres being sparsely distributed throughout the longitudinal smooth muscle layer. The circularly arranged smooth musculature of the sphincter-segment lacks an adrenergic nerve supply. The vagus nerve carries sympathetic adrenergic fibres to the lower oesophagus and the cardia. Species differences between the innervation pattern in rhesus monkeys and cats are outlined: No adrenergically innervated ganglia occur in the submucosa of the cat. However, part of the myenteric ganglia in cats exhibit an adrenergic innervation pattern similar to that seen in submucous ganglia of the rhesus monkey. They might therefore be regarded as morphologically equivalent to the plexus submucosus which is, however, present in the whole gut. The density of the noradrenergic ground-plexus in the muscularis mucosae of the cat's oesophagus is less than that of the corresponding plexus in rhesus monkeys. The influence of noradrenaline upon the smooth musculature and the neurons from myenteric as well as submucous ganglia is discussed. From the point of view of the adrenergic innervation there is no structure corresponding to the sphincterlike lower oesophageal segment.

Notes: 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 μg/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.

Notes: Summary The localization of catecholamines has been investigated in the extrahepatic biliary duct system of cats, guinea-pigs and rhesus monkeys. In fluorimetric determinations noradrenaline was found to be the main primary catecholamine present in the biliary tract of rhesus monkeys. There exist regional differences in the noradrenaline content: Fairly low amounts were detected in the lower fundus of the gall-bladder (0.28 μg/g). Increasing concentrations were measured in the corpus vesicae felleae (0.35 μg/g), reaching a maximum level in the collum vesicae (0.49 μg/g) and the ductus cysticus (0.50 μg/g). The noradrenaline content of the choledochus and the choledocho-duodenal junction including Oddi's sphincter was much lower: 0,27 and 0,25 μg/g respectively. The noradrenaline level in the small intestine of the rhesus monkey amounted to less than half the concentration found in the biliary ducts. Neither dopamine nor adrenaline have been detected. Fluorescence microscopical analysis reveals the presence of adrenergic nerves in the bile ducts which correspond to the measured noradrenaline concentrations: All parts of the biliary duct system in the different species investigated contain an elaborate perivascular adventitial plexus and adrenergic fibres confined to adventitial non-adrenergic ganglia. In guinea-pigs adrenergically innervated ganglia extend into the smooth muscle layer. The smooth muscle layer of the gall-bladder and the terminal choledochus in cats and rhesus monkeys is penetrated by a wide-meshed adrenergic ground plexus. This plexus was absent in guinea-pigs. The smooth musculature of the sphincter Oddi lacks a specialized adrenergic nerve supply in all species investigated. Finally, bound to the arterial vascular bed inside the propria in all parts of the biliary tract from all species investigated a prominent perivascular plexus is present. It is concluded that the smooth musculature of the gall-bladder and the terminal choledochus (the sphincter region excluded) in cats and monkeys receives 1. a direct sympathetic noradrenergic inhibitory innervation and 2. an indirect sympathetic noradrenergic inhibitory innervation which acts on intrinsic excitatory neurons and is present in all species investigated. The functional significance of the direct and indirect inhibitory innervation to the smooth musculature of the gall-bladder is discussed in detail.