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)

The circulating levels of ACTH and alpha-melanocyte stimulating hormone (alpha-MSH) were measured in 9 patients with Nelson's syndrome after the administration of saline, ovine corticotrophin releasing factor (oCRF), bromocriptine or TRH. The concentrations of ACTH were grossly elevated and alpha-MSH levels ranged from undetectable to higher than the normal range. In seven of eight subjects there was a rapid corticotrophic response, but no change in the alpha-MSH level, following oCRF. This response was delayed in one subject. Following oCRF injection, the plasma oCRF profile was variable but circulating oCRF was detectable even at the end of the experiment in all cases. There was no significant change in circulating ACTH or alpha-MSH following either bromocriptine or TRH. Cultured tumour cells from one case of Cushing's disease showed a corticotrophic response but no change in alpha-MSH to oCRF and the response was enhanced by vasopressin. Bromocriptine added to the same tumour depressed ACTH secretion without affecting the output of alpha-MSH. The present data suggest that the tumours in these subjects are responsive to oCRF and arise from corticotrophs rather than melanotrophs.
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PMID:The effect of ovine corticotrophin releasing factor (oCRF), bromocriptine and TRH on the secretion of ACTH and alpha-MSH in Nelson's syndrome and Cushing's disease. 302 73

In order to determine whether dopamine plays a role in the control of neuropituitary function in pregnant women during labour, blood levels of nicotine (NSN)- and estrogen (ESN)-stimulated neurophysins were measured in 119 women treated orally with placebo (n = 59, control group) or 5 mg bromocriptine, a potent dopaminergic receptor agonist (n = 60, experimental group). Serum samples were taken before drug ingestion (basal sample) and at delivery. The serum basal concentrations of NSN and ESN were similar in both groups of pregnant women in labour. At delivery, serum ESN levels were similar in all women regardless of the treatment, whereas NSN concentrations were significantly lower in the bromocriptine-treated women than in those who were given placebo. In additional experiments the effect of 5 mg bromocriptine on the serum concentrations of NSN and ESN was tested for 6 hours after drug ingestion in 10 healthy, non-pregnant women and in 8 women in the 3rd trimester of pregnancy. Bromocriptine did not modify the circulating levels of NSN and ESN in either of these 2 groups of women. Since NSN and ESN are thought to be associated with vasopressin and oxytocin, respectively, these results indicate that in non-pregnant women and in pregnant women during late pregnancy dopaminergic stimulation with a dopaminergic receptor agonist does not inhibit the release of either vasopressin or oxytocin during rest. In contrast, dopaminergic receptor stimulation appears to play an inhibitory role in the regulation of vasopressin, but not oxytocin secretion in pregnant women in labour.
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PMID:Effect of bromocriptine on neurophysin secretion in pregnant women in labour. 317 10

Bromocriptine (5-100 microgram; 6.7 X 10(-9) - 1.3 X 10(-7) mol.), SK&F 38393 (2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine, 0.5-5 mg; 1.7 X 10(-6)-1.7 X 10(-5) mol.) and apomorphine (20-200 microgram; 6.4 X 19(-8)-6.4 X 10(-7) mol.) administered into rat kidneys perfused with physiological solution containing vasopressin and pretreated with an alpha-adrenoreceptor antagonist produced vasodilator responses similar to dopamine (50-100 microgram; 2.6 X 10(-8)-5.3 X 10(-7) mol.). THe responses to bromocriptine, SK&F 38393 and apomorphine were found to be significantly reduced by the dopamine receptor antagonist ergometrine (50 microgram; 1.1 X 10(-7) mol.). Metoclopramide (250 microgram; 7.4 X 10(-7) mol.) was found to be an effective antagonist of dopamine, bromocriptine, SK&F 38393 and apomorphine. Apomorphine (20, 50 microgram; 6.4 X 10(-8), 1.6 X 10(-7) mo.) was found to act as a partial agonist on dopamine receptors in this preparation.
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PMID:A comparison of the responses to some dopamine-receptor agonists and antagonists in the isolated perfused rat kidney. 697 30

Bromocriptine, a dopaminergic agonist, inhibited the growth of human small cell lung cancer (SCLC) implanted as tumor xenografts in athymic nude mice; the effect was dose dependent. In mice bearing a SCLC with ectopic vasopressin production, plasma levels of human vasopressin-associated neurophysin decreased concomitantly. Electron microscopy of tumor tissues revealed marked degenerative changes, including pyknosis, densely aggregated chromatin masses, and vacuolization of cytoplasm after bromocriptine treatment. When a SCLC cell line, NCI-H69, was grown in semisolid medium, bromocriptine inhibited its clonal growth in a dose-related manner. Coincubation with dopamine D2 receptor antagonist, metoclopramide, or domperidone, completely blocked the inhibitory effect of bromocriptine. Receptor studies with a dopamine D2 receptor ligand, [125I]iodosulpride, showed high affinity binding sites on the membranes of SCLC cells. These results indicate that SCLC cells are enriched with dopamine D2 receptors, which may mediate the growth-inhibitory effect of bromocriptine on SCLC. Dopaminergic agonists may be useful in the medical treatment of SCLC.
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PMID:Inhibition of growth of human small cell lung cancer by bromocriptine. 801 64

Development of the fetal ovine pituitary is essential for normal maturation and initiation of the parturition process, as well as for orchestrating endocrine responses to stress in utero. Increases in the biosynthesis of ACTH and prolactin (PRL) occur in the late-gestation fetal sheep pituitary. In the anterior lobe (AL) of the pituitary, pro-opiomelanocortin (POMC) biosynthesis and processing are primarily regulated by corticotrophin-releasing hormone and vasopressin. However, POMC in the intermediate lobe (IL) and PRL in the AL are known to be primarily regulated by dopamine, via the D2 receptor, in adult sheep. Because of the importance of ACTH and PRL during gestation we have investigated a potential role of dopamine in the control of both IL melanotrophs and AL lactotrophs and corticotrophs, in late gestation. Catheters were implanted into a maternal femoral artery and vein, fetal carotid artery and jugular vein as well as into the amniotic cavity. At day 130 of gestation, fetuses were infused intravenously with either the specific D2 receptor agonist bromocriptine (n = 5) or vehicle (n = 5), for 5 days. Blood samples were taken throughout the experiment and pituitaries were removed at the end of the treatment period. Bromocriptine caused a significant decrease (> 50%) in POMC mRNA levels in the IL. In contrast, bromocriptine had no significant effect on POMC mRNA levels or distribution in the AL. Fetal arterial ACTH and cortisol concentrations were unaffected by the bromocriptine infusion, compared with vehicle-infused controls. There was a dramatic decrease (> 80%) in plasma PRL concentrations, compared with the control fetuses. However, PRL mRNA levels in the AL were not significantly affected by bromocriptine. In conclusion, we have found that bromocriptine inhibits aspects of both melanotroph and lactotroph function in late-gestation fetal sheep. The data indicate that the fetal pituitary possesses functional D2 receptors in late gestation.
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PMID:Dopaminergic regulation of pituitary function in the late-gestation fetal sheep. 886 85

Pituitary adenomas are the most common pituitary disorder affecting pregnancy, and prolactinomas are the most common of the hormone-secreting pituitary adenomas. Hyperprolactinemia must be corrected to allow ovulation and fertility. Bromocriptine has been shown to be safe for use during early gestation. There is less than a 2% risk of microprolactinoma enlargement during pregnancy but a greater than 15% risk of symptomatic enlargement of a macroprolactinoma. Treatment options for patients with macroadenomas include stopping bromocriptine when pregnancy is diagnosed and reinstituting with tumor enlargement, continuous bromocriptine throughout pregnancy, and prepregnancy tumor debulking by surgery. The diagnosis of acromegaly may be difficult to make during pregnancy and relies, in part, on the persistence of the normal pulsatile secretion of growth hormone and loss of this secretory characteristic with a tumor. The growth hormone oversecretion may exacerbate tendencies to gestational diabetes, fluid retention, and hypertension. Treatment for acromegaly and other tumors generally may be deferred until after delivery. There are rare reports of enlargement of clinically nonfunctioning and growth hormone secreting tumors during pregnancy, and surveillance is needed. Tumors may need to be differentiated from lymphocytic hypophysitis. Patients with chronic hypopituitarism usually will need treatment with gonadotropins or pulsatile GnRH to become pregnant and may need increased steroid coverage during labor and delivery. Hypopituitarism developing during pregnancy is usually caused by lymphocytic hypophysitis and usually also will require steroid replacement therapy. Hypopituitarism arising postpartum may be caused by either lymphocytic hypophysitis or Sheehan's syndrome, and the latter may present as an acute or chronic syndrome. Borderline diabetes insipidus may manifest during pregnancy because of increased vasopressin degradation caused by markedly increased levels of placental vasopressinase. Treatment with desmopressin usually is satisfactory. Patients presenting with either anterior or posterior pituitary insufficiency in the peripartum period should always be evaluated for function of the other portion of the pituitary.
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PMID:Pituitary diseases in pregnancy. 988 Jan 16

The neurochemical mechanisms involved in post-ictal antinociception remain to be elucidated. Application of electroconvulsive shock (ECS) to rats results in post-ictal antinociception. The objective of this study was to identify endogenous substances that could participate in antinociception during post-ictal depression induced by ECS (70 mA, 60 Hz, 1 s). Antinociception was measured by the rat paw-pressure test, in which increased sensitivity is induced by intraplantar injection of carrageenan. This test proved to be efficient in detecting the electroshock-induced antinociception. Intense post-ictal antinociception was observed over a period of 30 min after the end of the seizure. It was used nonspecific opioid and specific vasopressin antagonists and the prolactin (PRL) release inhibitor to test the reversal of antinociception. Administration of naloxone (5, 7.5 and 10 mg/kg) blocked the post-ictal antinociception. The V(1) (125 microg/kg) and V(2) (250 microg/kg) vasopressin receptor antagonists ([beta-mercapto-beta,beta-cyclopentamethylenepropionyl(1),O-Et-Tyr(2),Val(4),Arg(8)]-vasopressin and [adamantaneacetyl(1),O-Et-d-Tyr(2),Val(4),Abu(6),Arg(8,9)]-vasopressin) also inhibited the nociceptive response. The antinociception blockade was more intense after administration of the V(1) receptor antagonist. Bromocriptine (4, 8 and 12 mg/kg) was able to reverse antinociception behavior during the post-ictal period. Morphine (1, 2 and 4 mg/kg), vasopressin (12.5, 100 and 400 microg/kg) and prolactin (100, 200 and 400 microg/kg) administration promoted a higher nociceptive threshold. It was administered the three substances with their respective antagonists to verify the opioidergic pathway and vasopressin and prolactin release interactions, and as a positive control. We observed that the tested mediators were released in an independent manner, indicating no interference in which other.
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PMID:Involvement of prolactin, vasopressin and opioids in post-ictal antinociception induced by electroshock in rats. 1501 57

The present study evaluated the effect of acute extracellular volume expansion (EVE) induced by intravenous injection of isotonic (0.15 m NaCl) or hypertonic saline (0.3 m NaCl) on prolactin, corticosterone, vasopressin, oxytocin and atrial natriuretic peptide (ANP) secretion. Male Wistar rats were treated with bromocriptine, sulpiride or dexamethasone. After isotonic and hypertonic EVE, the control group showed a significant increase in the plasma concentrations of prolactin, corticosterone, ANP and oxytocin. The increase in ANP and oxytocin levels in response to hypertonic EVE was more pronounced than to isotonic EVE. Bromocriptine and sulpiride treatments did not modify corticosterone, ANP and oxytocin responses to either isotonic or hypertonic EVE. The increases in prolactin and oxytocin, but not ANP, were blocked in dexamethasone pretreated rats. In conclusion, isotonic or hypertonic EVE induced an increase in the plasma concentrations of prolactin, corticosterone, ANP and oxytocin. The increases in ANP and oxytocin were independent of plasma concentrations of prolactin. The increases in prolactin and oxytocin were blocked by the inhibition of the hypothalamo-pituitary-adrenal (HPA) axis by dexamethasone. However, dexamethasone did not alter the increase in ANP secretion induced by isotonic or hypertonic EVE. Therefore, prolactin might participate in regulation of the hydroelectrolytic balance in mammals; however, in the present study, there was no evidence for direct interaction with ANPergic and oxytocinergic systems. In addition, the responses of prolactin and oxytocin induced by isotonic or hypertonic EVE are modulated by the HPA axis.
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PMID:Interaction of prolactin, ANPergic, oxytocinergic and adrenal systems in response to extracellular volume expansion in rats. 1518 58