Serotonergic involvement in stress-induced vasopressin and oxytocin secretion

Abstract

Objective: To investigate the involvement of serotonin (5-hydroxytryptamine -5-HT) receptors in mediation of stress-induced arginine vasopressin (AVP) and oxytocin (OT) secretion in male rats. Design: Experiments on laboratory rats with control groups. Methods: Different stress paradigms were applied after pretreatment with intracerebroventricular infusion of saline or different 5-HT antagonists. Results: Restraint stress (5 min), hypotensive hemorrhage or dehydration for 24 h increased AVP secretion fivefold and OT secretion threefold. Swim stress for 3 min had no effect on AVP secretion, but increased OT secretion threefold. Ether vapor or hypoglycemia had no effect on AVP or OT secretion. The restraint stress-induced AVP response was inhibited by pretreatment with the 5-HT 2Aþ2C antagonists ketanserin (KET) and LY-53857 (LY) and the 5-HT 3þ4 antagonist ICS-205930 (ICS), whereas the 5-HT 1A antagonist WAY-100635 (WAY) had no effect. The OT response to restraint stress was inhibited by WAY, KET and LY but not by ICS. KET and LY inhibited OT response to dehydration, and LY inhibited OT response to hemorrhage. Neither of the antagonists affected AVP responses to dehydration or hemorrhage, nor the swim stress-induced OT response.

A two-choice sound localization procedure for detecting lateralized tinnitus in animals

“…One potential source of stress is water deprivation, which increases the levels of hormones and proteins (c-Fos) that are associated with stress (Arnhold, Wotus, & Engeland, 2007;Jørgensen, Knigge, Kjaer, & Warberg, 2002). However, most studies have only looked at the initial effects of restricting an animal's water intake (e.g., 1 or 6 days as in the previously cited studies), and a longer-term study found that hormonal levels in rats on water restriction had returned to normal by 8 weeks (Sakellaris & Vernikos-Danellis, 1974).…”

“…Indeed, it is possible that the occasional reinstatement of tinnitus in some rats following anesthesia was due to the stress of being anesthetized rather than being a direct effect of the anesthesia itself. As previously noted, animals could be exposed to loud sound without anesthesia by restraining them, although they would have to be acclimated to this, because restraint itself can cause stress (e.g., Jørgensen et al, 2002)-and they would then hear the loud sound, which would also be stressful.…”

Uma visão psicobiológica da personalidade limítrofe

“…22,23 Jorgensen has also demonstrated that fluoxetine increases oxytocin and vasopressin release. The interconnection between these serotonin and neuropeptide systems opens up new avenues for psychopharmacological research.…”

Study of neurogenic involvement in arginine-vasopressin and oxytocin release under basal and environmentally stimulated conditions

“…Tg8/KO mice (a knockout strain for the monoamine oxidase-A gene, which presents high levels of NE OXT expression or release [57,58]. The involvement of 5-HT receptors in the mediation of stress-induced AVP and OXT secretion [59] or of NE receptors to in AVP secretion from the PVN in pain modulation [60] has also been identified. DA-ergic input has been observed in the PVN and SON.…”