Coeliac-superior Mesenteric Ganglion Research Articles

Enkephalin immunoreactive nerve fibres and cell bodies in sympathetic ganglia of the guinea-pig and rat

The occurrence and distribution of enkephalin-like immunoreactivity was studied by light microscopy, using an indirect fluorescent-labelled antibody technique, in the superior cervical ganglion, the inferior mesenteric ganglion and the coeliac-superior mesenteric ganglion complex of the guinea-pig and rat. In the guinea-pig a very dense network of enkephalin-positive fibres was observed in the inferior mesenteric ganglion and a less dense one in the coeliac-superior mesenteric ganglion complex. In both ganglia some ‘small intensely fluorescent’ cells were immunoreactive. In the superior cervical ganglion only few fluorescent fibres were seen but several ‘small intensely fluorescent’ cells were enkephalin-positive. In the rat the inferior and coeliac-superior mesenteric ganglia contained medium-dense networks of enkephalin-positive fibres. An irregularly distributed network of fluorescent fibres was observed in the superior cervical ganglion, where also several principal ganglion cells were enkephalinimmunoreactive, particularly after colchicine treatment. These findings indicate the presence of several peripheral neuron systems containing enkephalin or a similar peptide. Several antisera raised to methionine- and leucine-enkephalin as well as to α- and β-endorphin were used. Some of these antisera were compared by incubating sections of the inferior mesenteric ganglion with increasing dilutions of antiserum as well as with antisera treated with increasing concentrations of methionine- and leucine-enkephalin, respectively. On the basis of these findings the problem of differentiating between methionine- and leucine-enkephalin is discussed.

On the occurrence of substance P-containing fibers in sympathetic ganglia: Immunohistochemical evidence

Several sympathetic ganglia of the guinea pig, cat and rat were studied with indirect immunofluorescence technique using antibodies to substance P (SP) and dopamine-β-hydroxylase (DBH), the latter of which represents a marker for noradrenaline containing neurons. In all ganglia studied SP-like immunoreactivity could be observed in certain nerve fibers (SP-positive fibers). Their number, localization fluorescence intensity and ‘fluorescence morphology’ varied considerably between the different ganglia as well as between species. In the inferior mesenteric ganglion and the coeliac-superior mesenteric ganglion complex of all species, and in particular of the guinea pig, a dense plexus of varicose SP-positive fibers was observed around the mostly DBH-positive, principal ganglion cells. In contrast no such fibers were seen in relation to the DBH-positive SIF cells of the ganglia. No SP-positive ganglion cells were observed in any of the ganglia studied. Previous biochemical and immunohistochemical studies have indicated that peripheral SP-positive fibers may represent the branches of primary sensory neurons. The rich supply of varicose, SP-positive nerve terminals, often surrounding the noradrenergic ganglion cells in a basket-like manner, may indicate that these fibers may play a functional role within the ganglia. Instead of merely passing through the ganglion they may be involved in special types of reflex arches.

Occurrence of somatostatin-like immunoreactivity in some peripheral sympathetic noradrenergic neurons

By means of the indirect immunofluorescence technique of Coons and collaborators, somatostatin-like immunoreactivity has been demonstrated in principal ganglion cells of some sympathetic ganglia. The noradrenergic nature of these cells was established by "staining" of the same or consecutive sections with antiserum to dopamine beta-hydroxylase [dopamine beta-monooxygenase; 3,4-dihydroxyphenylethylamine, ascorbate:oxygen oxidoreductase (beta-hydroxylating), EC 1.14.17.1], the enzyme converting dopamine to noradrenaline (norepinephrine). In guinea pigs the somatostatin immunoreactive material was found in almost two-thirds of all principal ganglion cells of the coeliac-superior mesenteric ganglion complex (anterior inferior part) and of the inferior mesenteric ganglion, but only in a few cells of the superior cervical ganglion. It appeared to be localized close to the Golgi complex. The present findings may represent a concomitant storage of a biogenic amine and a small peptide in a neuron. Because both noradrenaline and somatostatin may fulfill a role as a neurotransmitter or modulator, the sympathetic neurons described in this study may represent an example of mammalian nerve cells not conforming to Dale's hypothesis, i.e., the one neuronone transmitter concept.

Immunohistochemical evidence of vasoactive intestinal polypeptide-containing neurons and nerve fibers in sympathetic ganglia

Neurons and nerve fiber networks showing immunoreactivity for vasoactive intestinal polypeptide have been observed in some sympathetic ganglia with the help of the indirect immunofluorescence technique. Antisera to tyrosine hydroxylase and dopamine β-hydroxylase were used to identify catecholamine cells on consecutive sections. In the coeliac-superior mesenteric ganglion complex and the inferior mesenteric ganglion of the guinea-pig very dense networks of vasoactive intestinal polypeptide-positive varicose nerve fibers were observed around the principal ganglion cells. Only very few immunofluorescent fibers were seen in relation to the small intensely fluorescent cells. Occasionally some immunoreactive principal ganglion cells were found. In the same ganglia of the rat a considerably less dense network of vasoactive intestinal polypeptide-positive nerve fibers was present. The superior cervical ganglia of both species contained only a few vasoactive intestinal polypeptide-immunofluorescent fibers and no positively reacting cells were found.