Evidence for a visceral afferent origin of substance P-like immunoreactivity in lamina V of the rat thoracic spinal cord.

A visceral afferent origin of substance P-like immunoreactivity in lamina V of the lower thoracic spinal cord of the rat was investigated. In transverse sections from normal animals there was a moderately dense substance P-immunoreactive innervation of lamina V. In some sections there was a dorsoventrally orientated fibre bundle from the superficial dorsal horn entering lamina V. In parasagittal sections, substance P-immunoreactivity in lamina V was found arranged in clusters, with a periodicity in the rostrocaudal axis of 200-600 microns. In some cases these were seen to be continuous with a dorsoventrally orientated fibre bundle from the superficial dorsal horn. After section of the splanchnic nerve there was a consistent reduction in the density of the substance P-like immunoreactivity in lamina V, with fewer clusters on the operated side. Adult rats treated neonatally with capsaicin showed a substantial reduction of substance P-immunoreactivity in laminae I and II and the virtual abolition of staining in lamina V. These results provide evidence of a visceral origin for some of the substance P-like immunoreactivity in lamina V of the rat thoracic spinal cord. In addition, they confirm that most of the substance P-immunoreactivity in the dorsal horn is of primary afferent origin.

[Catecholamine concentration in several structures of the cat and rabbit sympathetic nervous systems during postnatal ontogenesis]. / Soderzhanie katekholaminov v nekotorykh strukturakh simpaticheskoi nervnoi sistemy koshek i krolikov v postnatal'nom ontogeneze

Studies have been made on the content of adrenalin and noradrenalin in the nervous fibers and ganglia of the sympathetic nervous system of cats and rabbits during a postnatal life. In all the structures investigated, high catecholamine content was found within the first month of life on the animals. On further development, total catecholamine content decreases. Age changes in catecholamine content of preganglionic sympathetic fibers and different sympathetic ganglia indicate an effective adrenergic regulation in early postnatal ontogenesis of cats and rabbits.

Distribution and origin of calcitonin gene-related peptide in the rat stomach and duodenum: an immunocytochemical analysis.

We studied the three-dimensional distribution of structures with calcitonin gene-related peptide-like immunoreactivity (CGRPI) in the rat stomach and duodenum, including the origins of these structures, using indirect immunofluorescence in both muscle strips and frozen sections. There was a very dense meshwork of CGRPI fibers in the circular and longitudinal muscle layers, and also in the myenteric and submucous plexuses of the stomach and duodenum. No CGRPI neurons were seen in the stomach, even in rats treated with colchicine; in the duodenum, there was a group of CGRPI cells in the myenteric and submucous ganglia. No regional differences were seen in the stomach and duodenum. We found by experimental manipulations that CGRPI fibers in the stomach were exclusively extrinsic in origin; some of such fibers in the duodenum were intrinsic in origin, though most were supplied by CGRPI cells outside the duodenum.

Immuno-electron microscopic identification of somatostatin in cells and axons of sympathetic ganglia in the guinea pig.

The superior cervical ganglia (SCG), celiac superior mesenteric ganglia (CMG), and splanchnic nerve of unoperated guinea pigs, as well as both proximal and distal stumps of a previously transected branch of the postganglionic plexus of the CMG, were immunostained for somatostatin (SS). In addition, the PAP technique was adapted for fine-structural visualization of SS. A greater proportion of cells were labeled for SS in the CMG than in the SCG. PAP molecules were present in one type of intraganglionic axons. Only two labeled axons were found in the splanchnic nerve. Neither proximal nor the distal stump of the transected CMG postganglionic nerve contained labeled axons. The present results support the hypothesis that the intraganglionic axons labeled for SS arise from SS-containing intraganglionic neurons.

Extraction and partial characterization of enkephalin-like peptides from splanchnic nerve.

A method is described for the extraction of enkephalin-like peptides from peripheral nerve using chloroform and acidic methanol to facilitate a differential extraction of peptides and lipid. Porcine splanchnic nerve contains enkephalin-like peptides in low amounts compared to porcine adrenal medulla and striatum. Gel filtration chromatography reveals the presence of enkephalin-like peptides in both processed and cryptic forms. This is the first reported isolation and partial characterization of these peptides in splanchnic nerve. The presence of these peptides in this nerve provides support for the contention that the splanchnic nerve can modulate catecholamine release from the adrenal medulla through an effect on opiate receptors located on chromaffin cells.

Vasoactive intestinal polypeptide-like immunoreactivity in nerves of the pancreatic islet of the teleost fish, Gillichthys mirabilis.

In the teleost fish, Gillichthys mirabilis, vasoactive intestinal polypeptide (VIP)-like immunoreactivity is present in some nerve fibres of the principal pancreatic islet and surrounding tissues, the vagus and splanchnic nerves, the coeliac ganglion and the wall of the intestine. The nerves of the pancreatic islet that contain VIP-like immunoreactivity probably correspond to one of the two types of non-cholinergic, non-adrenergic (peptidergic) nerve previously described in this fish. Similarities in the localisation of hormonal peptides in fish and mammals suggest that the regulation of gastroenteropancreatic physiology in fish may resemble that of mammals.