Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bilateral adrenalectomy (ADX) leads to increased ACTH synthesis and secretion. It is thought that endogenous glucocorticoids exert a feedback mechanism at both pituitary and brain levels. The present study has been performed in order to determine the effect of ADX on the release of hypothalamic neuropeptides with corticotropin-releasing activity (CRA) and if there exists a median eminence site of glucocorticoid action to regulate hypothalamic-pituitary-adrenal (HPA) function. Adrenalectomized and sham-operated male rats were killed at different periods after surgery (2, 5, 7 and 14 days) and trunk blood was collected for ACTH and corticosterone (B) concentrations measurement. Brain (median eminence, ME; and medial basal hypothalamus, MBH) and pituitary (anterior lobe, AP; and neurointermediate lobe, NIL) tissues were dissected in order to evaluate either peptide content or in vitro hormone release. The results indicate that ADX blunted plasma B levels and increased AP ACTH content and secretion in a time-related fashion up to the 14th day. ADX significantly decreased both CRF and CRA contents in the ME at all periods studied; ME arginine-vasopressin (AVP) increased 7 and 14 days after ADX. MBH CRF decreased after ADX, but returned to sham value 2 weeks later; similarly, MBH AVP decreased at all periods after ADX. Removal of endogenous glucocorticoids did not vary neither oxytocin (OXY) content in the ME and MBH nor AVP and OXY contents in the NIL. In our superfusion experiments, we found that ADX increased basal AVP release and did not change spontaneous CRF secretion from ME terminals. Dexamethasone (Dxm, 10 nM) diminished AVP but not CRF output by ME tissues from adrenalectomized rats. A direct relationship was found between ME CRF and 28 mM KCl (hK+)-induced CRF release by MEs from adrenalectomized rats. ME fragments from adrenalectomized rats were hyperresponsive to kH+ stimulation of AVP release. Dxm (10 nM) decreased the hK(+)-evoked CRF and AVP release by MEs from adrenalectomized rats. ADX and dexamethasone treatment did not influence basal and hK(+)-elicited ME OXY release. Additionally, a rapid glucocorticoid inhibitory effect on ACTH secretion by isolated AP cells from both sham and adrenalectomized rats was found, and an in vitro corticotrope hyporesponse to 0.63 nM CRF and 9.25 nM AVP stimulation during several days after ADX.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Changes in the hypothalamo-corticotrope axis after bilateral adrenalectomy: evidence for a median eminence site of glucocorticoid action. 184 20

The effect of inescapable electric foot shock stress on vasopressin (VP) release was studied in conscious rats. In sham-operated animals, foot shock stress markedly increased plasma beta-endorphin-like immunoreactivity whereas plasma VP levels (RIA) remained unchanged. However, after selective ablation of the anterior lobe of the hypophysis, foot shock stress produced an 8-fold increase in plasma VP concentrations. Injection of hypertonic saline did not change plasma VP levels in adenohypophysectomized (Ahx) rats, while in sham-operated rats VP levels increased in response to this osmotic challenge. Neurointermediate lobes or medial basal hypothalami (MBH; containing the median eminence region) were superfused in vitro and stimulated electrically; as compared to sham operations, the evoked release of VP from the neurointermediate lobes was abolished, whereas that from the MBH was markedly (13-fold) enhanced when the tissues were taken from Ahx rats. The VP-like immunoreactivity released from the MBH of Ahx rats comigrated with synthetic arginine-VP on Sephadex G-15 column chromatography. Similarly, as found in Ahx rats, foot shock stress markedly raised plasma VP levels in totally hypophysectomized rats, whereas after selective ablation of the neurointermediate lobe of the hypophysis VP levels increased only slightly after stress. In conclusion, our data indicate that 1) foot shock stress induces the release of VP from some site other than the neurohypophysis, probably from the median eminence region, in Ahx rats; and 2) an increase in plasma osmolality is a powerful stimulus for the release of VP from the neurohypophysis but cannot release VP from the median eminence region. Thus, our results support the concept of a morphological and functional differentiation of the vasopressinergic neurosecretory system.
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PMID:Foot shock stress-induced release of vasopressin in adenohypophysectomized and hypophysectomized rats. 315 65

In the present investigation, we examined the influence of both genetic background and sex factors in the rat hypothalamo-pituitary-adrenal (HPA) axis function under both basal and post adrenalectomy (ADX) conditions. For these purposes adult female and male rats, from Sprague-Dawley (S-D), Fischer (F344/N), Lewis (LEW/N) and Buffalo (BUF) strains, were decapitated in basal condition or several (2, 7 and 14) days after ADX. Plasma stress hormones levels and adrenal corticosterone (B) concentration as well as peptide (ACTH, CRH and vasopressin, AVP) content in different tissues (anterior pituitary, AP; medial basal hypothalamus, MBH), were then evaluated by specific assays. Our results indicate that: a) despite no sex- and strain-related differences in AP ACTH and MBH ACTH secretagogues in basal condition, there exits a clear sexual dimorphism in plasma ACTH levels as well as in both plasma and adrenal B concentrations, with values significantly higher in females than in males, regardless the strain; b) ADX abolished plasma B levels and increased AP ACTH output in a time-dependent fashion up to the 14th day post surgery; c) AP ACTH content decreased 2 days after ADX, except in BUF female rats, thereafter tending to either recover or increase sham values by two weeks post ADX; d) ADX decreased MBH CRH at all periods studied, except in BUF female animals on day 14; e) ADX clearly diminished MBH AVP only in S-D rats, and f) a sexual dimorphism was also found in AP ACTH in 7-day-ADX S-D rats and in 14-day-ADX S-D and F344/N animals; also, a dimorphic pattern in MBH CRH was found in 7-day-ADX S-D as well as in 14-day-ADX F344/N and LEW/N rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sex and strain variability in the rat hypothalamo-pituitary-adrenal (HPA) axis function. 775 81