Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The stimulating effect of different pituitary hormones on longitudinal bone growth was determined with tetracycline as intravital marker in hypophysectomized rats. Growth hormone was found to be the most effective growth stimulating pituitary hormone. At considerably higher doses, thyrotrophic hormone (TSH) and prolactin also showed growth stimulating pituitary hormone. At considerably higher doses, thyrotrophic hormone (TSH) and prolactin also showed growth stimulating activity. TSH exerts its effect via the production of thyroxine, whereas the growth stimulation by prolactin seems to be a direct effect of this hormone, similar to the effect of growth hormone. The LH, FSH, ACTH, MSH, vasopressin and oxytocin preparations did not stimulate longitudinal bone growth.
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PMID:Stimulation of longitudinal bone growth by hypophyseal hormones in the hypophysectomized rat. 19 Aug 39

Rat and bovine adrenal cortical microsomal fractions isolated at 27,000 x g and 105,000 x g accumulated Ca2+ by a nonmitochondrial, ATP-dependent uptake system that was stimulated by ammonium oxalate. ACTH (2 mU/ml) significantly increased Ca2+ uptake in bovine adrenal cortical microsomes and in adrenal microsomes from acutely hypophysectomized rats, but only when the hormone was preincubated with intact tissue and not when it was added after homogenization. ACTH did not stimulate C2+ uptake in adrenal microsomes isolated from nonhypophysectomized, ether-stressed rats, in which basal Ca2+ uptake was higher than that observed in microsomes from hypophysectomized animals. The peptides oxytocin, insulin, and TSH did not stimulate Ca2+ uptake by adrenal cortical microsomes. ACTH preincubated with intact tissue had no effect on Ca2+ uptake in microsomes from liver, kidney, esophagus, or aorta. cAMP, 5'-AMP, and several other nucleotides, nucleosides, and related compounds stimulated adrenal cortical microsomal Ca2+ uptake by as much as 540% of control. The stimulatory effects of nucleotides, unlike those of ACTH, were apparent even when the agents were added after homogenization. However, like ACTH, the nucleotides were unable to stimulate Ca2+ uptake when they were added to isolated membrane vesicles during Ca2+ uptake measurements. It is suggested that the microsomal Ca2+ uptake system may respond to physiological stimulants and regulate Ca2+ availability in the intact cell.
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PMID:The effect of adrenocorticotropin and nucleotides on Ca2+ uptake in adrenal cortical microsomal vesicles. 21 5

In adrenalectomized rats, histochemical and immunohistochemical properties of the following secretion products have been investigated: 1. CRF-granules in the outer layer of the median eminence; 2. neurosecretory material (NSM) in the supraoptico-hypophysial system of the hypothalamus; 3. secretory granules in the TSH-cells of the anterior lobe of the hypophysis; 4. secretory granules in the ependymal cells of the subcommissural organ (SCO); 5. beta-cell-granules in the islets of Langerhans in the pancreas. All these substances are characterized by their stainability with the so-called "Gomori method". The experiments have included studies into: a) the extractability of the substances by various solvents; b) the digestability of the substances by pepsin or trypsin; c) their histochemically detectable content of disulfide groups, arginine and periodic acid-Schiff (PAS) reactive carbohydrates; d) their reaction with porcine-neurophysin-II-antibodies. All substances exhibited a positive reaction for disulfide groups. Based on their solubility properties, their resistance to pepsin or trypsin, their respective content of PAS-reactive carbohydrates and their failure to react with anti-neurophysin serum the "Gomori-positive" granules in TSH-, SCO- and pancreatic beta-cells can be distinguished from one another and from CRF- and neurosecretory granules. In contrast, CRF-granules and NSM showed identical properties. Taking into consideration data from the biochemical and histochemical literature, the present findings suggest that CRF-granules and NSM consist of closely related biochemical substances.
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PMID:Histochemical and immunohistochemical properties of the CRF-granules and other "Gomori-positive" substances of the rat. 76 9

The reaction products of plasma enzyme degradation of TRH were identified by thin layer chromatography. The enzyme in normal rat plasma yields proline and pGlu-His as major reaction products. High concentrations of proline decrease peptide cleavage, resulting in greater amounts of acid TRH. The apparent Km of the enzyme is 4.1 X 10(-6) M. LHRH and neurotensin are competitive inhibitors with Ki of 5 X 10(-6) M and 1.5 X 10(-5) M, respectively. Somatostatin, MIF, oxytocin, arg-vasopressin, arg-vasotocin, neurophysin II and glucagon do not compete; and pGlu-His-Pro-OH, Glu-His-Pro-OH, pGlu-His, His-Pro-NH2, and Pro-NH2 do not affect enzyme activity. These data suggest that the substrated requires pGlu and a terminal or internal amide to complex with the enzyme. The enzyme is markedly inhibited by Cu++, Bal, benzamadine, p-(chloromercuri)-benzoic acid, moderately affected by EDTA and puromycin, and unaffected by mercaptoethanol. TSH does not affect enzyme activity while LH inhibits it moderately at high concentrations (300-600 pg/ml).
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PMID:Characteristics of the plasma TRH-degrading enzyme. 81 19

Plasma levels of prolactin and TSH were determined by radioimmunoassay in urethaneanaesthetized lactating rats during suckling. Oxytocin release was monitored by recording intramammary pressure. Application of ten pups, 3 h after administration of urethane (1-1 g/kg, i.p.), evoked a parallel rise in prolactin and TSH concentrations which reached a maximum during the 3rd hour of suckling and then declined. Peak hormone concentrations represented a 25-fold increase in prolactin and a ten-fold increase in TSH. Suckling also elicited a pulsatile (every 5-10 min) release of 0-5--1-0 mu. oxytocin. The gradual rise in prolactin and TSH occurred between the 1st and 20th oxytocin pulses. Intravenous injection of thyrotrophin-releasing hormone (TRH) into unsuckled, anaesthetized lactating rats resulted in a 7- to 30-fold increase in TSH concentration, whereas prolactin levels showed no substantial change. These results indicate that suckling releases TSH as well as prolactin in the urethaneanaesthetized rat. However, the absence of prolactin release after injections of TRH makes it unlikely that both endocrine responses are regulated solely by the actions of this one releasing hormone.
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PMID:Plasma concentrations of prolactin and thyrotrophin during suckling in urethane-anaesthetized rats. 82 93

In eight patients undergoing chronic hemodialysis, ultrafiltration was performed for 1 h in each patient. The concentration of urea nitrogen, creatinine, ADH, cortisol, GH, prolactin and TSH was measured in plasma and the filtering solution, and the permeability of each substance was determined. The plasma concentration of ADH coincided with that of the filtering solution, and no significant difference was noted between the permeability of creating and ADH. In contrast, cortisol, GH, prolactin and TSH were not detected in the filtering solution. Chromatographic study showed that ADH in the filtering solution coincided with synthetic ADH. From a comparison of the permeability with the molecular weight, it was suggested that ADH in the blood exists in free form without binding with plasma proteins or neurophysin.
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PMID:Permeability of antidiuretic hormone and other hormones through the dialysis membrane in patients undergoing chronic hemodialysis. 91 84

To examine the relationship between corticotrophin releasing hormone (CRH), arginine vasopressin (AVP) and oxytocin (OXT) we have studied the responses of adenohypophyseal and neurohypophyseal hormones to CRH in eight patients (age 26-64 years, six female) with suspected pituitary-dependent Cushing's syndrome during bilateral, simultaneous inferior petrosal sinus catheterization. Blood samples were taken from both petrosal sinuses and a peripheral vein before, and at 5-min intervals for 15 min after, an intravenous injection of 100 micrograms human CRH1-41. CRH increased sinus AVP concentrations in all eight patients and OXT concentrations in four of five patients studied. Although AVP concentrations often increased in both sinuses, the side of maximal AVP rise was termed side(max-AVP). CRH did not affect peripheral or petrosal sinus mean concentrations of LH, FSH, GH or TSH. While there was no change in mean peripheral concentrations of AVP, OXT, ACTH, ACTH precursors or prolactin after CRH, sinus concentrations of OXT, ACTH and prolactin on side(max-AVP) were markedly elevated over contralateral values. CRH did not increase mean sinus concentrations of ACTH precursors. In seven patients with either no radiological abnormality or the pituitary fossa or a small adenoma the mean ACTH precursor/ACTH ratio in blood sampled from all sites was 2.1 +/- 0.16 (mean +/- SEM, n = 50). In a patient with a large, locally invasive tumour the mean ACTH precursor/ACTH molar ratio was 32.1 +/- 1.3 (n = 12; P less than 0.001), suggesting that alterations in this molar ratio may reflect the biological properties of the tumour. The source of CRH-stimulatable AVP and OXT remains uncertain.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Corticotrophin releasing hormone (CRH1-41) stimulates the secretion of adrenocorticotrophin, vasopressin and oxytocin but not adrenocorticotrophin precursors: evidence from petrosal sinus sampling in man. 184 86

The neurotransmitter histamine participates in the neuroendocrine regulation of pituitary hormone secretion by an indirect action at a hypothalamic level where histaminergic neurons are abundant. The effect of histamine is caused by activation of postsynaptic H1- or H2-receptors. Histamine stimulates the secretion of ACTH, beta-endorphin (mediated by CRH and AVP), alpha-MSH (mediated by dopamine and peripheral catecholamines), and PRL (mediated by dopamine, serotonin and AVP), and participates in the stress-induced release of these hormones and possibly in the suckling- and estrogen-induced PRL release. The release of GH and TSH is predominantly inhibited by histamine; however, uncertainty exists regarding its role and the hypothalamic factors involved. Histamine increases the secretion of LH in females (mediated by GnRH), and may be involved in the mediation of the estrogen-induced LH surge. AVP and oxytocin are stimulated by histamine, probably by an effect in the supraoptic and paraventricular nuclei of the hypothalamus.
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PMID:The role of histamine in the neuroendocrine regulation of pituitary hormone secretion. 206 91

Cold exposure increases blood levels of TSH and thyroid hormones by stimulating the secretion of TRH from the median eminence. Thyroid hormones reduce TRH release and cellular levels of TRH mRNA. Using quantitative in situ hybridization to measure changes in cellular levels of various neuropeptide mRNAs, the present studies demonstrate that cold exposure also increases cellular levels of TRH mRNA in neurons of the paraventricular nucleus (PVN), supporting the concept that TRH mRNA levels are reflective of TRH secretion in these neurons. The effect of cold appeared to be specific for TRH expression in the PVN, because cold exposure did not influence cellular levels of TRH in the reticular thalamic nucleus or beta-actin and oxytocin mRNAs in the PVN. Cellular levels of mRNA encoding CRH were elevated by cold exposure. This latter observation is predictable based on the cold-induced activation of the hypothalamic-pituitary-adrenal axis. There was a 24-h rhythm and a time of day difference in the effect of cold on TRH mRNA levels in the PVN. Time of day differences in the effect of cold on CRH mRNA levels were not apparent. Cold exposure appeared to elevate TRH mRNA levels in all neurons of the PVN, indicating that the neurally mediated effect of cold on TRH expression can override the inhibitory effects of circulating T3 within the same neuronal population.
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PMID:Cold exposure elevates cellular levels of messenger ribonucleic acid encoding thyrotropin-releasing hormone in paraventricular nucleus despite elevated levels of thyroid hormones. 212 45

Male Wistar rats were hypophysectomized 1 week before restraint stress. The hypophysectomy caused a decrease of blood vasopressin (30%, P less than 0.05) and a diminution of the thyroid activity (the thyrocyte height lowered to 43%, P less than 0.01). The TSH concentration was about normal and remained constant during the experiment. After 20 min of the restraint stress, the vasopressin concentration reached 178% (P less than 0.01), but the thyroid did not response in rats with the intact hypophysis. In the hypophysectomized rats, the restraint stress caused neither essential changes of the blood vasopressin nor the thyroid function as compared with the hypophysectomized control. An injection of vasopressin (5.0 ng/100 g) or oxytocin (15.0 ng/100 g) resulted in a slight activation of the thyroid in the hypophysectomized rats but significantly stimulated in when combined with the restraint stress; vasopressin injection led to an increase of the thyrocyte height to 152% (P less than 0.01), oxytocin--to 126% (P less than 0.05). Thus, in hypophysectomized rats, vasopressin and oxytocin can influence the thyroid directly. Stressful conditions facilitate the thyroid stimulating effect of these nonapeptide neurohormones.
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PMID:[Thyroid stimulating effect of exogenous vasopressin and oxytocin in hypophysectomized rats during immobilization stress]. 233 92


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