Immunohistochemical properties and spinal connections of pelvic autonomic neurons that innervate the rat prostate gland

Abstract

Autonomic innervation of the prostate gland supplies the acini, and non-vascular and vascular smooth muscle. The activity of each of these tissues is enhanced by sympathetic outflow, whereas the role of the parasympathetic nervous system in this organ is unclear. In the present study, a range of methods was applied in rats to determine the location of autonomic neurons supplying this gland, the immunohistochemical properties of these neurons, the spinal connections made with the postganglionic pathways and the distribution of various axon types within the gland. Injection of the retrograde tracer, FluoroGold, into the ventral gland visualised neurons within the major pelvic ganglion and sympathetic chain. Fluorescence immunohistochemical studies on the labelled pelvic neurons showed that most were nonadrenergic (also containing neuropeptide Y, NPY), the others being non-noradrenergic and containing either vasoactive intestinal peptide (VIP) or NPY. Sympathetic dye-labelled neurons were identified by the presence of varicose nerve terminals stained for synaptophysin on their somata following lesion of sacral inputs. Parasympathetic innervation of dye-labelled neurons was identified by continued innervation after hypogastric nerve lesion. Most noradrenergic prostate-projecting neurons were sympathetic, as were many of the non-noradrenergic VIP neurons. Parasympathetic prostate-projecting neurons were largely non-noradrenergic and contained either VIP or NPY. All substances found in retrogradely labelled somata were located in axons within the prostate gland but had slightly different patterns of distribution. The studies have shown that there are a significant number of non-noradrenergic sympathetic prostate-projecting neurons, which contain VIP.

Immunohistochemical characterisation of cholinergic nerve fibres supplying accessory genital glands in the pig

“…This observation was confirmed by Dhami and Mitchell (1994), who found that in this species many pelvic adrenergic neurons projecting to the seminal vesicles, but not to the prostate, contained this peptide. Kepper and Keast (1995), in turn, revealed that many, if not all adrenergic nerve fibres innervating the rat prostate contained NPY.…”

“…VIP has been demonstrated in nerve fibres supplying the prostate and seminal vesicles in the guinea-pig, rat, cat, rabbit, mouse and humans. VIP-immunoreactive nerve fibres have been mainly associated with the basis of the glandular epithelium and, in smaller proportion, with the smooth muscle coat and blood vessels (Alm et al, 1980;Vaalasti et al, 1980Vaalasti et al, , 1986Larsen et al, 1981;Gu et al, 1983;Stjernquist et al, 1983;Polak and Bloom, 1984;Lamano Carvalho et al, 1986;Higgins and Gosling, 1989;Lange and Unger, 1990;Properzi et al, 1992;Jen et al 1995;Kepper and Keast, 1995;Tainio, 1995). Very little is known about the physiological role of VIP in AGG.…”

“…leu-enkephalin (leu-ENK), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), somatostatin (SOM), calcitonin gene-related peptide (CGRP) and nitric oxide (Alm et al, 1980(Alm et al, , 1981Stjernquist et al, 1987;Aumuller et al, 1989;Higgins and Gossling, 1989;Crowe et al, 1991;Kepper and Keast, 1995;Jen et al, 1995;Tainio, 1995;Hedlund et al, 1996;Chow et al, 1997;Sjostrand et al, 1998).…”

Striated Perineal Muscles: Location of Autonomic, Sensory, and Somatic Neurons Projecting to the Male Pig Bulbospongiosus Muscle

“…Therefore, we retain that the autonomic source of porcine BSM innervation is sympathetic in nature, as the mammalian STGs and CMGs are considered typical sympathetic ganglia for the innervation of genital organs (Sjöstrand, 1965;Heym and Lang, 1986;Majewski andHeym, 1991, 1992;Kolbeck and Steers, 1993;Kaleczyc et al, 1995;Kepper and Keast, 1995;Papka et al, 1996;Kaleczyc, 1998). Also the somata found in the PGs could represent sympathetic efferent neurons, even if these microganglia are mixed autonomic ganglia consisting of adrenergic-sympathetic and cholinergicparasympathetic neurons (Dhami and Mitchell, 1991;Keast, 1991Keast, , 1995Dail, 1996;Jen et al, 1997;Kaleczyc, 1997).…”

Sensory and Autonomic Neurons Project Both to the Smooth Retractor Penis and to the Striated Bulbospongiosus Muscles. Neurochemical Features of the Sympathetic Subset

“…These two sources of RPM and BSM innervation are considered typical sympathetic ganglia for the innervation of genital organs (Sj€ ostrand, 1965;Majewski and Heym, 1992;Kolbeck and Steers, 1993;Kepper and Keast, 1995;Papka et al, 1996;Kaleczyc, 1998).…”