Glucocorticoids rapidly inhibit oxytocin-stimulated adrenocorticotropin release from rat anterior pituitary cells, without modifying intracellular calcium transients

Abstract

Glucocorticoid hormones suppress the secretion of ACTH evoked by secretagogues such as CRF and arginine vasopressin. In this study, we investigated the effects of glucocorticoids on ACTH release induced by oxytocin (OT) and on intracellular free calcium ion levels in corticotropes prepared from the adenohypophyses of female Wistar rats.Pulsatile additions of physiological concentration of OT (10 nM) to superfused anterior pituitary cells caused pulsatile ACTH release about 4-fold above basal secretion with similar peak amounts of ACTH du ring subsequent OT pulses. Exposure of the cells to corticosterone (100 nM) or to a selective glucocorticoid receptor agonist RU 28362 (100 nM) for 30 min suppressed OT-stimulated but not basal ACTH release by approximately 60%. Inhibition gradually disappeared during subsequent pulses of OT in the absence of corticosterone. Pretreatment with I

Review: Central non-glucocorticoid inhibitors of the hypothalamo-pituitary-adrenal axis

“…HPA axis activity is attenuated during lactation coincident with a period when central levels of OT are elevated (Lightman & Young 1989). However, evidence for a stimulatory role for OT persists, with the observation that OT stimulated pulsatile release of ACTH from superfused anterior pituitary cells harvested from female rats (Link et al 1993).…”

Effect of oxytocin on free intracellular Ca2+ levels and progesterone release by human granulosa-lutein cells.

“…Thus, depletion of intracellular Ca 2 + stores (by the ionophore ionomycin) completely abolished the response of the cells upon oxytocin stimulation. To our knowledge, oxytocin exerts its effect via stimulation of phospholipase-C in the human myometrium (12) and rat pituitary (13,14). A number of other receptors (e.g.…”

“…We, therefore, tried to address these points in the present study. We investigated whether activation of oxyto-tin receptors can cause elevations of intracellular free calcium concentrations in human granulosa-lutein cells in a manner similar to that we reported previously in cultured human myometrial cells (12) and rat pituitary corticotrophs (13,14). In addition, we examined the role of oxytocin in progesterone release, and the effect of hCG exerted on the release of oxytocin by cultured human granulosa-lutein cells.…”

Ηθική Ενίσχυση, Ελευθερία Και Το Μηχάνημα Του Θεού

“…Παρομοίως, τα γλυκοκορτικοειδή, τα οποία χρησιμοποιούνται ευρέως για την θεραπεία του άσθματος και άλλων φλεγμονωδών διαταραχών, πιστεύεται πως ρυθμίζουν τόσο την έκκριση της οξυτοκίνης, όσο και την έκφραση των υποδοχέων σεροτονίνης σε κάποια τμήματα του εγκεφάλου (Link et al 1993;Liberzon et al 1997). Ο Kosfeld και η ομάδα του διερεύνησαν την σύνδεση της οξυτοκίνης με την εμπι-στοσύνη σε ένα απλό παιχνίδι συνεργασίας (Kosfeld et al 2005).…”