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)

ACTH-release by primary cultures of rat anterior pituitary cells in response to CRF, vasopressin, epinephrine, norepinephrine and VIP is readily suppressible by dexamethasone. Rat hypothalamic extract-induced ACTH release is less sensitive to the inhibitory effect of dexamethasone than that elicited by CRF and the other secretagogues mentioned above. In studying the additive and potentiating effect on ACTH release of CRF in combination with vasopressin, VIP and the catecholamines it became evident that only the combination of micromolar concentrations of epinephrine or norepinephrine together with nanomolar concentrations of CRF will make ACTH release significantly less sensitive to the suppressive effect of dexamethasone. Other combinations of CRF and vasopressin or CRF and VIP will render ACTH release as suppressible to dexamethasone, as that elicited by each of these compounds by itself. This observation in the rat might explain at least in part the observation that a diminished suppressibility of the pituitary-adrenal axis to dexamethasone can be found in patients with psychiatric disease, especially depression.
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PMID:High concentrations of catecholamines selectively diminish the sensitivity of CRF-stimulated ACTH release by cultured rat pituitary cells to the suppressive effects of dexamethasone. 301 54

The inhibition of ACTH secretion by glucocorticoids in vivo is biphasic, with rapid early suppression followed by transient recovery and a late inhibitory phase. To evaluate whether this biphasic effect of glucocorticoids occurs at the pituitary level, the effects of corticosterone (B) on stimulated ACTH release were analyzed in rat anterior pituitary cell cultures. Preincubation with 1 microM B inhibited the ACTH response to 10 nM CRF in a biphasic manner, with rapid inhibition after 10-40 min of preincubation, followed by partial recovery between 40-80 min, and a later phase of inhibition after 80-140 min. Preincubation with B for 40 or 120 min caused a dose-dependent suppression of CRF-stimulated ACTH release, with ED50 values of 416 +/- 21 and 45 +/- 12 nM B, respectively. Pretreatment with B also caused a biphasic inhibitory effect on the stimulatory action of vasopressin, angiotensin II, and norepinephrine on ACTH release. However, addition of these stimuli in combination with CRF surmounted B inhibition of CRF-stimulated ACTH release. B also inhibited the ACTH-releasing effects of postreceptor stimuli, including 8-bromo-cAMP, phorbol 12-myristate 13-acetate, and 1,2-dioctanoylglycerol. In the presence of cycloheximide (10 microM), the early inhibitory effect of B was unchanged, but the delayed effect was decreased. Whereas preincubation with B for 40 min inhibited ACTH release, but not total intracellular plus released ACTH, preincubation for 120 min decreased both released and total ACTH. These findings demonstrate that the two inhibitory effects of B on ACTH release differ in their kinetics, steroid sensitivity, and dependence on protein synthesis. The inhibitory effect of B on ACTH responses to stimuli with different mechanisms of action suggests that the suppressive effects of B are mainly exerted at a site distal to the formation of the second messengers involved in hormonal activation of ACTH release.
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PMID:Biphasic inhibition of adrenocorticotropin release by corticosterone in cultured anterior pituitary cells. 301 77

CRF-41 and vasopressin are the major part of the hypothalamic complex responsible for the release of ACTH. The potentiated response of the corticotroph to mixtures of the peptides and their co-localization in the same neurosecretory vesicles would indicate their obligatory co-secretion in many stress situations. The occurrence of CRF at peripheral sites especially in the placenta and in the plasma of women in their third trimester of pregnancy is suggestive of further roles for this peptide although care should be exercised in interpreting simple immunohistochemical staining in certain tissues. When ACTH is released from the pituitary several other peptides which form part of its precursor are co-released. The effect of these peptides on the adrenal gland and the way their activity is expressed has led to a post-secretional proteolytic control mechanism being proposed.
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PMID:CRF: its regulation of ACTH and pro-opiomelanocortin peptide release and its extra hypothalamic occurrence. 301 60

In addition to cAMP-dependent mechanisms, stimulation of pituitary ACTH secretion by various stimuli, including CRF, may involve phospholipid and arachidonic acid turnover. To determine the role of phospholipase A2 activation in corticotroph function, we studied the effect of exogenous arachidonic acid, phospholipase A2, and the phospholipase A2 activator melittin on ACTH release in cultured rat anterior pituitary cells. Incubation with 1-100 micron arachidonic acid, 0.01-1 micron melittin, 0.1-10 U/ml phospholipase A2, and 0.01-10 nM CRF caused dose-dependent increases in ACTH release to 8.1 +/- 1.1- (+/- SE), 16.2 +/- 0.9-, 13.6 +/- 1.2-, and 2.9 +/- 0.3-fold; respectively. The participation of the major pathways of arachidonic acid metabolism in the control of ACTH release was analyzed in cells treated with nordihydroguaiaretic acid, a lipoxygenase inhibitor; indomethacin, a cycloxygenase inhibitor; and 5,8,11,14-eicosatetraynoic acid, an inhibitor of both pathways. The effects of arachidonic acid, melittin, and CRF were partially blocked by 10 micron nordihydroguaiaretic acid and 5,8,11,14-eicosatetraynoic acid, but were significantly enhanced by 10 micron indomethacin. These results suggest that arachidonic acid is mainly metabolized through the lipoxygenase pathway to a stimulatory metabolite and, to a lesser extent, through the cycloxygenase pathway to an inhibitory metabolite. Arachidonic acid release from anterior pituitary cells labeled with [3H]arachidonic was analyzed during cell column perifusion and stimulation by CRF and other secretagogues. Two-minute pulses of CRF (10 nM), vasopressin (10 nM) and phorbol 12-myristate 13-acetate (100 nM) caused immediate 1.5- to 2-fold increases in [3H]arachidonic acid release, and melittin (100 nM) caused a 5-fold increase in [3H]arachidonic acid release. The ability of both exogenously added and endogenously generated arachidonic acid to stimulate ACTH secretion, together with the stimulation of arachidonic acid release by ACTH secretagogues and the attenuation of stimulated ACTH release by lipoxygenase blockers, indicate that lipoxygenase products of arachidonic acid metabolism participate in the control of ACTH secretion.
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PMID:Role of arachidonic acid in the regulation of adrenocorticotropin release from rat anterior pituitary cell cultures. 301 33

Recently, it has been reported that oxytocin (OT), classically known for its function during parturition and lactation, is secreted in response to stressful stimuli in male rats. In these and in the present report it was found that swimming stress, restraint stress, ether stress, and footshock stress elevate OT secretion without affecting arginine-vasopressin (AVP) secretion. In the present studies, we investigated the possible modulation of OT secretion by CRF which is known to be released during stress. Male and female rats received intraventricular (icv) injections of 0.75 nmol (5 micrograms) rat CRF and were killed 5 min after the treatment. CRF significantly elevated OT secretion in male and female rats 3.4- and 4-fold, respectively. Plasma AVP levels were not affected by the treatment. The effect of CRF on OT release was structure specific since rat CRF, ovine CRF, and sauvagine were equipotent releasers of OT while an inactive analog to CRF, ovine CRF did not change plasma OT levels. In another set of experiments rats were pretreated with either CRF-antiserum (0.5 ml iv) or dexamethasone (20 micrograms/rat ip) and then injected with icv CRF. Both CRF-antiserum and dexamethasone blocked the rise in ACTH release after icv CRF completely but did not influence the OT response. This suggests CRF may be acting centrally but not at the level of the neurohypophysis to change OT secretion. Since parvocellular but not magnocellular neurons of the paraventricular nucleus have been demonstrated to be steroid sensitive in immunohistochemical studies, we suggest CRF may act directly or indirectly upon magnocellular neurons to increase OT release. Intravenous administration of 0.75 nmol CRF increased both OT and AVP levels in peripheral blood. The magnitude of this increase was similar (2- to 4-fold stimulation) to responses after icv administration of CRF. Intravenous administration of CRF results in hypotension and may therefore cause a baroreceptor mediated release of AVP and OT. From the above evidence we conclude: physical and mental stresses which do not result in changes in blood volume or osmolality evoke an increase in OT secretion while AVP secretion remains unchanged; CRF administered icv mimics OT responses observed after ether stress or footshock stress; CRF may play a role in regulating stress-induced OT secretion in the rat.
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PMID:Central administration of corticotropin-releasing factor modulates oxytocin secretion in the rat. 301 36

The present study was performed to investigate the potential of human medullary thyroid carcinoma (MTC) cells to secrete ACTH, beta-LPH/beta-EP. In addition, these studies might shed further light on the possible synthesis of a common precursor molecule for calcitonin (CT), ACTH and beta-LPH/beta-EP. MTC tissue was obtained from 10 patients (6 familial, 4 sporadic) without clinical and biochemical signs of Cushing's syndrome. Single cell suspensions were cultured for 1 to 2 weeks. Mean basal release of beta-LPH/beta-EP was 0.76 +/- 0.29 (SE) ng/10(6) cells/4 h (n = 10). Dibutyryl cyclic AMP (3 mM) stimulated beta-EP release significantly in 3 out of 7 cultures, while Ca2+ (2 mM) had no effect at all. The effects of the physiological regulators of pituitary ACTH and beta-LPH/beta-EP secretion, synthetic corticotropin-releasing factor (CRF-41) and vasopressin (LVP) were also studied in these MTC cell cultures. LVP (100 nM) had no effect on beta-EP release from MTC cells of all 8 cultures investigated. CRF-41 (10 nM) stimulated beta-EP release from 5 cultures and was without effect on 4. Maximal stimulation was noticed with 10 nM, while the effect of 100 nM CRF-41 was lower or absent. Stimulation was most outspoken in 3 cultures of familial MTC, whereas in 2 cultures of sporadic MTC CRF-41 stimulated beta-EP release marginally only after a 24 h incubation. LVP and/or CRF-41 stimulated CT release significantly in 3 cultures from sporadic MTC, while in these cultures the effect of CRF-41 on beta-EP release was either very small or absent.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Secretion of adrenocorticotropin, beta-endorphin and calcitonin by cultured medullary thyroid carcinoma cells. Effects of synthetic corticotropin-releasing factor and lysine vasopressin. 302 Aug 52

We describe a new method for successive immunofluorescence detection of multiple peptides in single paraffin tissue sections. Immunoglobulins were inactivated at 130 degrees C after each labeling step while tissues were protected with a mixture of phosphate-buffered saline and glycerin. The feasibility of the method is demonstrated by double-staining of rat pituitary corticotrophs with anti-ACTH[1-24] and anti-ACTH[17-39] antiserum. The method is applicable to brain tissue, since single neurons of ovine paraventricular hypothalamus could be triple stained with anti-vasopressin, anti-neurophysins I and II, and anti-CRF antiserum. The usual absorption controls and crossreactivity tests, as well as peptide staining, can be performed on the same tissue section. This new labeling procedure should prove useful in endocrinology, clinical pathology, and the neurosciences.
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PMID:Multiple immunolabeling in histology: a new method using thermo-inactivation of immunoglobulins. 302 76

CRF stimulates the synthesis and secretion of proopiomelanocortin-derived peptides from AtT-20 mouse pituitary tumor cells. This study has shown that there is a specific binding site for CRF located on the plasma membrane of these cells. Both [125I]iodo-Tyr0CRF and noniodinated CRF (10(-11)-10(-7) M) stimulated, in a dose-dependent manner, the secretion of equimolar amounts of beta-endorphin-like immunoactivity from AtT-20 cells. Disuccinimidyl suberate, a cross-linking agent, was used to demonstrate specific binding of [125I]iodo-Tyr0CRF to plasma membranes from these cells. After cross-linking [125I] iodo-Tyr0CRF, the membrane proteins were solubilized with sodium dodecyl sulfate and electrophoresed on a 10% polyacrylamide gel. A single radioactively labeled band, corresponding to a mol wt of 66,000, was identified by autoradiography. [125I]Iodo-Tyr0CRF binding to these membranes was inhibited by 10(-7) M unlabeled CRF or an equimolar concentration of the CRF analog sauvagine. Similar concentrations (10(-7) M) of TRH, GnRH, insulin, [Arg8]vasopressin, somatostatin, and ACTH did not inhibit [125I]iodo-Tyr0CRF binding to the plasma membranes. Incubation of AtT-20 cells for 24 h in the presence of 10 nM dexamethasone reduced [125I]iodo-Tyr0CRF binding by 80% compared to that in untreated cells. Dexamethasone also inhibited the CRF-stimulated beta-endorphin-like immunoactivity secretory response. These data indicate that binding of CRF to a specific membrane protein is an integral component in the stimulation of AtT-20 cells by CRF.
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PMID:Identification of a corticotropin-releasing factor-binding protein in the plasma membrane of AtT-20 mouse pituitary tumor cells and its regulation by dexamethasone. 303 86

Angiotensin II and CRF are but two of the several regulatory peptides which exert specific actions in the brain that are complementary with their peripheral effects upon end organs such as the anterior pituitary and adrenal glands. In the pituitary, the two peptides act in a coordinate manner on the corticotroph to regulate ACTH release. In the adrenal gland, angiotensin II receptors are abundant in the zona glomerulosa but are also present in the medulla, where the occurrence of CRF receptors and actions on catecholamine release reveals an additional site at which the two peptides exert related actions, in this case in the peripheral neuroendocrine system. Within the brain, the mapping of AII and CRF binding sites by topical autoradiography has provided new information about the distribution and potential functions of receptors for the two peptides. The central receptors for AII are distributed in a characteristic pattern in brain regions concerned with drinking, regulation of adrenergic function and arterial blood pressure, and control of pituitary hormone secretion. Thus, in addition to its recognized modulatory effects in the peripheral adrenergic system, angiotensin II may be involved in the central control of catecholamine release and action. A central action of AII on the release of regulatory peptides such as vasopressin and CRF, both of which are present in neurones of the paraventricular nucleus, is indicated by the high concentration of AII receptors in this region. Also, the high density of AII receptors in the median eminence suggests that AII modulates the hypothalamic secretion of neuropeptides such as CRF by actions at their site of release, as well as on the cell bodies of neurones responsible for peptide synthesis. The highly localized pattern of AII receptors at numerous specific sites in the brain differs from the more general distribution of many other CNS receptors, and reflects the selective actions of AII on discrete neural systems that subserve precisely integrated functions within the central nervous system. The widespread distribution of CRF receptors, with prominent localization in the cortical and limbic regions, is consistent with the more general neuroregulatory actions of CRF in the brain, and with the presence of immunoreactive CRF in several regions of the brain including the cortex, limbic system, and centers involved in the control of autonomic function. The cortical and limbic receptors are clearly relevant to the effects of centrally administered CRF on both behavioral and visceral responses, with prominent autonomic changes including increased catecholamine release and hypertension.
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PMID:Brain receptors for hypothalamic hormones. 303 94

The effects of selective agonists and antagonists of type 1 (V1) and type 2 (V2) vasopressin receptors on the secretion of ACTH in vitro by segments of adenohypophysial tissue and in vivo in rats pretreated with pentobarbitone and chlorpromazine were studied in the presence and absence of the 41 amino acid-containing peptide, corticotrophin-releasing factor-41 (CRF-41). The non-selective vasopressin receptor agonist, arginine vasopressin (AVP) and the V1-receptor agonist, felypressin caused dose-related increases in ACTH release in vivo and in vitro but the V2-receptor agonist, desmopressin was only weakly active in this respect. Their actions in vitro were antagonized competitively by the V1-receptor antagonist, d(C2H5)2-AVP, but were unaffected by the V2-receptor antagonist, d(CH2)5-D-Iso2-Thr4-AVP. Arginine vasopressin, felypressin and desmopressins in concentrations considerably lower than those necessary to elicit directly the release of ACTH, potentiated, in a dose-related manner, the activity of CRF-41 in vitro. The potentiating effects were not antagonized by the V2-receptor antagonist or by low concentrations of the V1-receptor antagonist. At a higher concentration, the V1-receptor antagonist reduced, but did not abolish, the potentiating effects of AVP and its analogues. However, at this concentration, it also exhibited weak intrinsic activity and, like the agonists, potentiated the response to CRF-41. The results suggest that the direct effect of AVP on ACTH release is mediated by V1-like receptors. The vasopressin receptors involved in the potentiation of CRF-41 activity appear to be different.
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PMID:Vasopressin receptors influencing the secretion of ACTH by the rat adenohypophysis. 304 Aug 81


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