The role of sympathetic and parasympathetic nerve systems on the smooth muscle of rat seminal vesicles – experimental results and speculation for physiological implication on ejaculation

Abstract

SUMMARYEjaculation is a process involving sympathetic and parasympathetic effects during different stages -emission and ejection. Some conditions of ejaculation dysfunction are associated with autonomic nerves. However, the exact effects of autonomic nerves on ejaculation are not well defined. Autonomic agonists induce different recorded trace patterns of seminal vesicular contraction. The different traces contain different components of phasic and tonic contraction, which may have physiological implications. In this study, we examined isolated rat seminal vesicle (SV) contraction by phenylephrine (PE), acetylcholine, and their respective antagonists and then speculated upon physiological roles of sympathetic and parasympathetic nerves on SV during ejaculation. We found that PE and Ach both achieved good contraction of rat SV. Compared to a1b for sympathetic and M1, M2 for parasympathetic receptors, a1a and M3 are the relatively dominant subtypes on rat SV. Adrenergic and cholinergic agonists cause different trace patterns of SV contraction. We speculated that the sympathetic effect is dominant during emission to squeeze seminal fluid out and that the parasympathetic effect is dominant during ejection to provide an anti-reflux effect on the ejaculatory duct.

Upregulated expression of NMDA receptor in the paraventricular nucleus shortens ejaculation latency in rats with experimental autoimmune prostatitis

“…However, other brain regions (eg the bed nucleus of stria terminalis, the nucleus paragigantocellularis, and the medial preoptic area) and multiple neurotransmitter receptors (eg opioid, serotonin, and α1a receptors) are also confirmed to participate in the regulation of ejaculation 22,32‐34 . These receptors and their neurotransmitters form complex networks of interactions, and our present results are probably an account of the balance of multiple effects.…”

Centrally mediated ejaculatory response via sympathetic outflow in rats: role of N‐methyl‐D‐aspartic acid receptors in paraventricular nucleus

“…Anatomy studies demonstrate that the main sympathetic signals to the accessory sex gland consist of the lumbar splanchnic nerve, caudal mesenteric plexus, hypogastric nerve, pelvic plexus, and its branches (Kihara et al, 1998). Recently, some studies have found that the sympathetic pathway is mainly through the a1a receptor, and the a1a antagonist has therapeutic potentials for premature ejaculation (Cl ement et al, 2006;Sato et al, 2012;Hsieh et al, 2014).…”

Somatic innervation contributes to the release of bulbourethral gland secretion in male rats

“…The autonomic innervation may mainly underlie the synthesis of Bu‐Gs secretion (Geuze & Slot, ). Considering that synthesis and release of secretion of others accessory glands, such as seminal vesicles, only depend on autonomic control (Hsieh et al ., ), it seems that the Bu‐Gs are the unique accessory sexual glands controlled by somatic and autonomic innervation.…”