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)

A patient with diabetes insipidus and hypothyroidism developed anovular menstrual cycles. Ovulation, which was followed by pregnancy, was induced by the administration of clomiphene. In the later stages of pregnancy, an increase in the dosage of vasopressin was necessary to achieve a satisfactory control of the symptoms of diabetes insipidus. Labour was induced before the estimated date of confinement by the intravenous administration of oxytocin and an intra-partum haemorrhage necessitated delivery by the lower-segment caesarean section. The post-partum period was uneventful. Lactation was suppressed on request from the patient.
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PMID:Clomiphene-induced pregnancy in a patient with diabetes insipidus and hypothyroidism. 52 68

Data are presented to show that vasoactive intestinal peptide (VIP) is synthesized and secreted by the hypothalamus and anterior pituitary and that it participates in the regulation of pituitary functions. Immunoreactive VIP in the hypothalamus and pituitary is increased following estrogen treatment and adrenalectomy and is reduced in hyperprolactinemic states. The level of VIP mRNA in the hypothalamus is increased during lactation and sexual maturation, while that in the anterior pituitary shows a sexual dimorphism and is increased with estrogen treatment and hypothyroidism. All these findings suggest a physiological regulation of hypothalamic and pituitary VIP gene expression in relation to its potential role as a neuroendocrine hormone. Furthermore, VIP stimulates prolactin (PRL) release at concentrations attainable in the hypophyseal-portal blood. Passive immunoneutralization studies with anti-VIP antisera suggest that endogenous VIP acts at multiple loci in the hypothalamic-pituitary axis to regulate PRL secretion, interacting possibly with other regulators of PRL secretion such as estrogen, serotonin, cholecystokinin, prostaglandins, galanin and oxytocin. Regarding other pituitary functions, although VIP has been shown to release growth hormone, ACTH, and vasopressin in vivo and in vitro, the physiological significance of these findings remains to be determined.
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PMID:Vasoactive intestinal peptide in the hypothalamus and pituitary. 190 91

Prenatal plus neonatal administration of methimazole (MMI), a procedure provoking marked hypothyroidism in rats, increased by about 100% the thymic content of oxytocin and severely (by approximately 80%) decreased the thymus weight, compared to euthyroid counterparts. Adult-onset, propylthiouracyl (PTU)-induced hypothyroidism, while provoking thymic involution, or thyroxine (T4) hyperthyroidism, did not affect oxytocin concentrations. Thymic involution and increases in thymus oxytoxin could also be obtained with repeated administration of the potent glucocorticoid dexamethasone. However, since corticosterone, unless subchronically injected at largely supraphysiological doses, was previously shown to have no influence on thymic parameters of young adult rats, a major involvement of the neonatal adrenal axis in oxytocin alterations could be excluded. It is suggested that the ontogenesis of thymic oxytocin production is under thyroid control.
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PMID:Effects of neonatal and adult thyroid dysfunction on thymic oxytocin. 212 6

Sustained hyperosmolality increases the levels of hypothalamic oxytocin (OT) and arginine vasopressin (AVP) messenger ribonucleic acids (mRNAs). Gonadectomy is known to abolish this response (12,18). In this study we investigated whether thyroidectomy would alter OT and AVP mRNA levels in the hypothalamic paraventricular nucleus (PVN) of the hyperosmotically stimulated rat. Male Sprague-Dawley rats underwent thyroidectomy (hypothyroid) or sham thyroidectomy (euthyroid) at 7 weeks of age. Three weeks later hypothyroid and euthyroid animals were administered 2% NaCl (6-11 days) or tap water and sacrificed at the end of the experiment. Northern blot hybridization was used to assess size and levels of hypothalamic OT and AVP mRNAs. Hypothyroid rats had significantly lower levels of serum thyroxine (T4) than their euthyroid cohorts (P < 0.0001). Both the euthyroid and the hypothyroid animals receiving 2% NaCl developed hypernatremia and increased the levels and the size of OT and AVP mRNAs compared to their tap water cohorts. We conclude that in contrast to gonadectomy, thyroidectomy does not alter the level of OT and AVP mRNAs in the hypothalamus of chronically hypernatremic male rats.
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PMID:Thyroidectomy does not alter hypothalamic oxytocin and vasopressin expression in chronically hypernatremic rats. 760 12

Congenital panhypopituitarism is a rare disease. It may be a complication of tumors, craniocerebral trauma, infection, granulomatous diseases, vascular pathologies, etc. In many cases no primary disease causing panhypopituitarism is found (idiopathic form). A potential reason is interruption of the pituitary stalk due to ischemic etiology in patients with cord encirclement and/or other birth injuries leading to interruption of the axonal transport of ADH and oxytocin as well as hypothalamic releasing hormones. This explains the ectopy of the neurohypophysis without diabetes insipidus and the hypoplasia of the adenohypophysis. GH-deficiency causes short stature and metabolic disturbances, LH-FSH-deficiency amenorrhoea/oligomenorrhoea, loss of libido and secondary sexual characteristics, TRH-deficiency hypothyroidism and ACTH-deficiency hypotonia, weakness, loss of pigmentation. We report a case of congenital panhypopituitarism. MR imaging of the brain revealed a hypoplastic adenohypophysis and a hypoplastic pituitary stalk which was interrupted in its superior segment. An ectopic neurohypophysis was found located in the area of the hypothalamus ("hypothalamic hot spot"). The ectopic neurohypophysis showed strong enhancement after intravenous application of Gd-DTPA. MR imaging of the hypothalamic-hypophyseal axis is well suited for the differentiation between congenital and acquired forms of panhypopituitarism in clinically uncertain cases.
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PMID:[Neuro-MR-findings in primary panhypopituitarism]. 979 7

Thyroid dysfunctions can produce reproductive problems. Untreated maternal hypothyroidism has serious consequences on development of offspring, resulting in stunted growth and mental retardation. The effects of propylthiouracyl-induced hypothyroidism (0.1 g l(-1) in drinking water starting 8 days before mating, or given to virgin rats for 30 or 50 days) on the serum profiles of hormones related to reproduction and mammary function (prolactin, growth hormone (GH), progesterone, corticosterone, oestradiol, insulin-like growth factor I (IGF-I), thyroid-stimulating hormone (TSH), triiodothyronine and tetraiodothyronine), and on mammary function in virgin, pregnant and lactating rats, were investigated. Propylthiouracyl treatment severely decreased circulating triiodothyronine and tetraiodothyronine concentrations, and increased serum TSH concentrations. Virgin rats showed prolonged periods of vaginal dioestrus, increased circulating progesterone concentrations and afternoon peaks of prolactin concentration, which are indicative of prolactin-induced pseudopregnancy. Propylthiouracyl-treated virgin rats had mammary development comparable to that of midpregnancy, and half of these rats had increased mammary casein and lactose concentrations. Serum prolactin concentrations were decreased on the afternoon of day 5 of pregnancy, increased during late pregnancy (days 15-21) and were normal during lactation. Circulating GH concentrations decreased on days 15-21 of pregnancy, whereas progesterone concentrations increased during late pregnancy and early lactation. Circulating oestradiol (measured in late pregnancy and in virgin rats), IGF-I and corticosterone concentrations were decreased. Although assessment of mammary histology showed no differences in extent of development, casein content was increased in propylthiouracyl-treated rats on day 21 of pregnancy; litter growth was severely reduced and at day 20 of age the pups were hypothyroid, with decreased GH serum concentrations. An acute suckling experiment was performed on days 10-12 of lactation to determine whether some impairment in mammary function or the suckling reflex might account for these differences. After an 8 h separation of mothers from their litters and 30 min of suckling, circulating prolactin values were not affected by propylthiouracyl treatment, but serum oxytocin concentration and milk excretion were reduced. In conclusion, hypothyroidism induces various alterations in the hormone profiles of virgin and pregnant rats, and induces pseudopregnancies and mammary development in virgin rats. These alterations do not appear to have an overt impact on the outcome of pregnancy and on mammary function during lactation, with the exception of the milk ejection reflex, which may account at least partially for the reduced litter growth.
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PMID:Effect of hypothyroidism on hormone profiles in virgin, pregnant and lactating rats, and on lactation. 1296 45

The aim of the present investigations was to examine the effects of the states of hypothyroidism or hyperthyroidism on vasopressin (AVP) and oxytocin (OT) release under conditions of equilibrated water metabolism as well as of osmotic stimulation, brought about by the dehydration or hypertonic saline administration. The euhydrated and simultaneously hypothyroid rats showed decreased hypothalamic AVP and OT content and somewhat higher but not significant neurohypophysial AVP content. In these animals the raised OT (but not AVP) plasma level has been observed. In hyperthyroid rats drinking tap water ad libitum the neurohypophysial AVP and OT content significantly diminished; plasma OT concentration (but not AVP) was then elevated. The state of osmotic stimulation was the reason of different response of the hypothalamo-neurohypohysial system function in hypo- or hyperthyroid rats. Significant decreases of neurohypophysial AVP and OT content were found in both hypothyroid dehydrated as well as hypothyroid hypertonic saline-treatment rats as compared with hypothyroid euhydrated ones. On the contrary, in the state of hyperthyroidism AVP content in the neurohypophysis distinctly raised in dehydrated and salt-loaded rats; in these last neurohypophysial OT content increased as well. Plasma OT (but not AVP) distinctly diminished in hyperthyroid and simultaneously dehydrated or hypertonic saline injected rats in relation to hyperthyroid control subgroup. Data from the present study suggest that: 1). altered thyroid gland function affects vasopressin and oxytocin release from the hypothalamo-neurohypophysial system in the state of equilibrated water metabolism; 2). the state of hypo- or hyperthyroidism modifies the response of AVP-ergic and OT-ergic neurons upon the osmoreceptors/osmodetectors stimulation. It may be supposed that OT-ergic neurons display greater than AVP-ergic neurons sensitivity upon the thyroid hormone influence.
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PMID:Vasopressin and oxytocin release and the thyroid function. 1521 63

Impaired urinary dilution leading to water retention and hyponatremia may occur in patients with cardiac failure, cirrhosis, pregnancy, oxytocin administration, hypothyroidism, glucocorticoid, and mineralocorticoid deficiency. The mechanisms for these defects predominantly involve the nonosmotic stimulation of arginine vasopressin release with up-regulation of aquaporin 2 water channel expression and trafficking to the apical membrane of the principal cells of the collecting duct. These perturbations are reversed by V2 vasopressin receptor antagonists. In contrast, urinary concentration defects leading to polyuria are vasopressin resistant. They may involve several factors, such as impaired countercurrent concentration secondary to down-regulation of Na-K-2Cl cotransporter. Vasopressin-resistant down-regulation of aquaporin 2 expression has also been described as a factor in impaired urinary concentration.
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PMID:Vasopressin and aquaporin 2 in clinical disorders of water homeostasis. 1851 89

Hypophysiotropic thyrotropin-releasing hormone (TRH) neurons, the central regulators of the hypothalamic-pituitary-thyroid axis, are located in the hypothalamic paraventricular nucleus (PVN) in a partly overlapping distribution with non-hypophysiotropic TRH neurons. The distribution of hypophysiotropic TRH neurons in the rat PVN is well understood, but the localization of these neurons is unknown in mice. To determine the distribution and phenotype of hypophysiotropic TRH neurons in mice, double- and triple-labeling experiments were performed on sections of intact mice, and mice treated intravenously and intraperitoneally with the retrograde tracer Fluoro-Gold. TRH neurons were located in all parts of the PVN except the periventricular zone. Hypophysiotropic TRH neurons were observed only at the mid-level of the PVN, primarily in the compact part. In this part of the PVN, TRH neurons were intermingled with oxytocin and vasopressin neurons, but based on their size, the TRH neurons were parvocellular and did not contain magnocellular neuropeptides. Co-localization of TRH and cocaine- and amphetamine-regulated transcript (CART) were observed only in areas where hypophysiotropic TRH neurons were located. In accordance with the morphological observations, hypothyroidism increased TRH mRNA content of neurons only at the mid-level of the PVN. These data demonstrate that the distribution of hypophysiotropic TRH neurons in mice is vastly different from the pattern in rats, with a dominant occurrence of these neurosecretory cells in the compact part and adjacent regions at the mid-level of the PVN. Furthermore, our data demonstrate that the organization of the PVN is markedly different in mice and rats.
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PMID:Distribution of hypophysiotropic thyrotropin-releasing hormone (TRH)-synthesizing neurons in the hypothalamic paraventricular nucleus of the mouse. 2073 94

Hormones regulate all aspects of male reproduction, from sperm production to sexual drive. Although emerging evidence from animal models and small clinical studies in humans clearly point to a role for several hormones in controlling the ejaculatory process, the exact endocrine mechanisms are unclear. Evidence shows that oxytocin is actively involved in regulating orgasm and ejaculation via peripheral, central and spinal mechanisms. Associations between delayed and premature ejaculation with hypothyroidism and hyperthyroidism, respectively, have also been extensively documented. Some models suggest that glucocorticoids are involved in the regulation of the ejaculatory reflex, but corresponding data from human studies are scant. Oestrogens regulate epididymal motility, whereas testosterone can affect the central and peripheral aspects of the ejaculatory process. Overall, the data of the endocrine system in regulating the ejaculatory reflex suggest that widely available endocrine therapies might be effective in treating sexual disorders in these men. Indeed, substantial evidence has documented that treatments of thyroid diseases are able to improve some ejaculatory difficulties.
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PMID:The hormonal control of ejaculation. 2286 1


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