Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although corticotropin-releasing hormone (CRH) acutely suppresses gonadotropin-releasing hormone (GnRH) secretion in animal models, its effect on the hypothalamic-pituitary-gonadal axis in humans is not well defined. To further evaluate the acute effects of adrenal axis activation on the hypothalamic-pituitary-gonadal axis in humans, we employed a model of insulin-induced hypoglycemia to stimulate endogenous CRH secretion in eight cycling women. Serum samples were obtained immediately before and 15, 30, 45, 60, 75, 90, and 120 min following iv insulin (0.15 U/kg) or saline injection. To ensure that the degree of hypothalamic-pituitary-adrenal activation in our subjects was similar to that observed in severely ill patients with hypogonadotropism, serum cortisol (F) levels were also measured in a group of acutely ill patients selected to have hypogonadotropism. All women experienced symptomatic hypoglycemia after insulin injection. Differences between serum F levels in hypoglycemic vs. control sessions were evident at 30 min (P < 0.01) and maximum at 120 min (P < 0.0001) after insulin injection. Serum estradiol levels were significantly lower following hypoglycemia than during control sessions (P < 0.001). In contrast, serum LH and FSH levels were not significantly different between control and hypoglycemic sessions. Peak serum F levels in these hypoglycemic women were similar to F levels in critically ill patients with hypogonadotropism. These results demonstrate that stress and/or hypoglycemia can acutely decrease circulating estradiol levels. In addition, these data suggest that endogenous CRH does not play a major role in acute suppression of GnRH (over 2 h) in humans. Further studies are required to identify longer term effects of CRH on GnRH secretion which may be present in hypothalamic amenorrhea or hypogonadotropic hypogonadism of critical illness.
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PMID:Serum estradiol but not gonadotropin levels decrease acutely after insulin-induced hypoglycemia in cycling women. 140 Aug 70

Hypothalamic pituitary functions were studied in 24 patients before, 6 months after and 1 year after cranial irradiation with or without radiosensitizing chemotherapy for nasopharyngeal carcinoma (NPC). The estimated average total dose was 5,000 cGy to the hypothalamus and pituitary gland. The radiosensitizing chemotherapy used was endoxan, 4,900 +/- 873 mg (mean +/- SD) and/or methotrexate, 113 +/- 30 mg. All patients had normal pituitary function before radiotherapy. There was a progressive increase in baseline serum thyrotropin (TSH) after radiotherapy. The basal serum follicle stimulating hormone (FSH) was significantly increased 6 months after radiotherapy and remained so at 1 year after radiotherapy. The TSH response to thyrotropin-releasing hormone (TRH) also progressively increased after radiotherapy, suggesting primary hypothyroidism due to neck irradiation. The peak serum TSH response to TRH became delayed after radiotherapy, suggesting a defect in TRH release. In male patients who did not receive chemotherapy, the LH response to luteinizing hormone-releasing hormone (LHRH) decreased after radiotherapy. After an initial rise in the FSH response to LHRH 6 months after radiotherapy, there was a reduction in the FSH response at 1 year. This suggests a defect in LHRH pulsatile release. However, in male patients who received radiosensitizing chemotherapy, both the FSH and LH responses to LHRH had declined at 1 year after radiotherapy, as compared with their responses at 6 months. However, these were still higher than those obtained before radiotherapy. This suggests further GnRH neuron damage, which was previously masked by chemotherapy-induced primary hypogonadism. The adrenocorticotropic hormone (ACTH) response to ovine corticotropin-releasing hormone (CRH) had not changed further at 1 year after radiotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of cranial irradiation on hypothalamus-pituitary function: follow-up study one year after radiotherapy. 168 Oct 15

The immunohistochemical localization of beta-endorphin in the normal testis (two patients) and in the pathologic testis (two cases of Sertoli Cell Only Syndrome, two cases of Klinefelter Syndrome, two cases of post-orchitis tubular sclero-hialinosis) was investigated. No beta-endorphin immunostaining was detected in the normal testis, while positive beta-endorphin immunostaining has been observed in pathologic tissues. These results indicate that, as in animals, beta-endorphin is present in human Leydig cells and may play a local role in regulating male reproductive function.
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PMID:Immunohistochemical localization of beta-endorphin in hyperplastic interstitial tissue of the human testis. 296 31

Gonadal, adrenal, and thyroid functions were evaluated in 70 men seropositive for human immunodeficiency virus (HIV) infection, clinically categorized as asymptomatic (n = 19), AIDS-related complex (ARC) (n = 9), or acquired immunodeficiency syndrome (AIDS) (n = 42). Twenty of 40 men (50 percent) with AIDS were hypogonadal. Mean serum testosterone concentrations in both ARC (292 +/- 70 ng/dl) and AIDS (401 +/- 30 ng/dl) men were significantly less than in asymptomatic (567 +/- 49 ng/dl) or normal men (608 +/- 121 ng/dl). Of these hypogonadal men, 18 of 24 (75 percent) had hypogonadotropic hypogonadism. Seven of eight hypogonadal men (88 percent) had a normal gonadotropin response to gonadotropin-releasing hormone administration. Hypogonadism correlated with lymphocyte depletion and weight loss. Adrenal cortisol reserve, evaluated by adrenocorticotropin stimulation, was normal in 36 of 39 patients (92 percent) with AIDS. Indices of thyroid function were normal with the exception of one ARC man with a low free thyroxine index. In conclusion, hypogonadism is common in men with HIV infection and may be the first or most sensitive endocrine abnormality.
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PMID:Endocrine disorders in men infected with human immunodeficiency virus. 334 69

The endocrine response to stress is complex. Elevations in the serum concentrations of the "classic" stress hormones, epinephrine and cortisol, occur following many kinds of physiologic challenge and are accompanied by elevations in corticotropin, GH, and glucagon levels. These changes are probably responsible for the hyperglycemia and hypercatabolism common to most critical illness. If volume depletion is present, vasopressin, renin, and aldosterone secretion are also likely to be stimulated. These hormones, if present in excess, may produce fluid retention and hyponatremia. In some critically ill patients, there is a dissociation of renin and aldosterone production called hyperreninemic hypoaldosteronism, but the clinical importance of this syndrome is poorly understood. Thyroid hormone metabolism is commonly affected by critical illness, which results in characteristic abnormalities of thyroid function testing known as the euthyroid sick syndrome. The reproductive axis is exquisitely sensitive to physiologic stress; hypogonadotropic hypogonadism is a common finding in critical illness. The ongoing challenge to the clinician is to determine whether seemingly abnormal hormone measurements in critically ill patients reflect an appropriate homeostatic response to severe illness or, instead, whether they denote an independent metabolic disorder that might actually cause or contribute to the patient's unstable condition. In view of the exceedingly complex (and poorly understood) interactions involved in the human response to a severe illness, a thoughtful approach to the whole patient is essential and far preferable to indiscriminate hormone testing. Such testing, at best, may be uninterpretable in light of the clinical circumstances or, at worst, may lead to therapeutic misadventures.
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PMID:The endocrine response to critical illness. 780 93

We report a case of double male syndrome, a type of Klinefelter's syndrome with 48,XXYY chromosome, associated with acromegaloidism. Although the patient presented acromegalic appearance, he did not show hypersecretion of growth hormone (GH). GH provocation tests revealed a rather low GH responses or no responses. After testosterone therapy, the GH responses were normalized except to Insulin tolerance test (ITT). On the other hand, the plasma corticotropin (ACTH) and cortisol levels were decreased paradoxically after hypoglycemia. Testosterone therapy did not restore this ACTH response. It was speculated that these abnormal GH and ACTH responses to hypoglycemia might indicate another congenital anomaly.
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PMID:48,XXYY syndrome associated with acromegaloidism. 838 24

We present here a rare case of hypopituitarism accompanied by growth hormone (GH) deficiency and hypogonadotropic hypogonadism, in which the patient attained normal height but was of eunuchoid appearance. A 23-year-old man who had not reached puberty was referred to Saitama Medical School for hormonal evaluation. Basal hormonal data and hormone-stimulating tests revealed impaired secretion of GH, gonadotropins and adrenocorticotropic hormone (ACTH). Serum levels of testosterone, estrone, estradiol and estriol were all below the detectable ranges. The patient's plasma ACTH responded to corticotropin releasing hormone, but not to insulin-induced hypoglycemia. Serum GH showed a minimal response to GH-releasing hormone, but was unresponsive to insulin-induced hypoglycemia. Serum luteinizing hormone and follicle stimulating hormone did not respond to luteinizing hormone-releasing hormone. The results were compatible with a diagnosis of hypothalamic hypopituitarism. Magnetic resonance images of the brain showed a small anterior pituitary, an ectopic posterior lobe and transection of the pituitary stalk. Although the patient showed signs of hypopituitarism, he finally attained normal height, possibly because of failed epiphyseal maturation. His bone mineral density was markedly reduced to 0.647 g/cm2 in the lumbar spine; this level was 61.7% of the average level of healthy young males. Our findings were compatible with a recently advocated view that estrogen is important in promoting epiphyseal fusion and in determining bone density in males as well as females.
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PMID:A patient of hypogonadotropic hypogonadism accompanied by growth hormone deficiency and decreased bone mineral density who attained normal growth. 1093 38

A few examples of hypothalamic, peptidergic disorders leading to clinical signs and symptoms are presented in this review. Increased activity of corticotropin-releasing hormone (CRH) neurons in the paraventricular nucleus (PVN) and decreased activity of the vasopressin neurons in the biological clock and of the thyroxine-releasing hormone (TRH) neurons in the PVN contribute to the signs and symptoms of depression. In men, the central nucleus of the bed nucleus of the stria terminalis (BSTc) is about twice as large and contains twice as many somatostatin neurons as in women. In transsexuals this sex difference is reversed, pointing to a role of this structure in gender. Luteinizing hormone-releasing hormone (LHRH) neurons are formed in the fetal olfactory placade and migrate along the terminal nerve fibers into the hypothalamus. In Kallmann's syndrome the migration process of the LHRH (gonadotropin-releasing hormone) neurons is aborted, which explains the joint occurrence of hypogonadotropic hypogonadism and anosmia in this syndrome. In postmenopausal women, the neurons of the infundibular nucleus hypertrophy and become hyperactive because of the disappearance of the estrogen feedback and contain hyperactive peptidergic neurons. Climacteric flushes may be caused by hyperactivity of the neurokinin-B or LHRH neurons in this nucleus. The hypocretin (orexin) neurons in the perifornical area are involved in sleep. In narcolepsy with cataplexy, a loss of these neurons, probably due to an autoimmune process, is found. Obese subjects with a mutation in the gene that encodes for leptin, the preproghrelin gene, or the alpha-melanocyte-stimulating hormone (alpha-MSH) gene have been described. Decreased numbers and activity of the oxytocin neurons in the PVN may be responsible for the absence of satiety in Prader-Willi syndrome. Moreover, a glucocorticoid receptor polymorphism is associated with obesitas and dysregulation of the hypothalamus-pituitary-adrenal axis. In contrast, two single nucleotide polymorphisms (SNPs) of the AGRP gene have been associated with anorexia nervosa.
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PMID:Neuropeptides in hypothalamic neuronal disorders. 1554 16

Studies in our laboratory and elsewhere have demonstrated numerous abnormalities of steroid and polypeptide hormone secretion in obesity: hyperestrogenemia and hypogonadotropic hypogonadism in obese men; diminished SHBG levels in both sexes; elevated free testosterone and free estradiol in obese women; PCOS-like gonadotropin and sex-hormone abnormalities in obese women; elevated serum insulin in both sexes; blunted stimulability of prolactin, growth hormone, and vasopressin in both sexes; and elevated basal levels and blunted stimulability and suppressibility of beta-endorphin in both sexes. All of these abnormalities have been clearly shown to be partly or completely reversible with weight loss, with the exception of the endorphin abnormalities. In that area, four out of the five studies reported show no reversibility with weight loss. Reversibility of nearly all the hormonal abnormalities of obesity (i.e., all but the hyperendorphinemia) by weight loss suggests that none of them is causative of obesity. Nevertheless, some of the reversible abnormalities may secondarily amplify the morbidity associated with obesity: the hyperinsulinemia may be related to the increased risk of hypertension, hyperlipidemia, coronary disease, and Type II diabetes; the elevated levels of free estradiol in obese women may be related to their increased risk of breast and endometrial cancer. The role of hyperendorphinemia in obesity clearly requires further investigation, since it is the only observed hormonal abnormality that appears to be non-reversible by weight loss, and also since there seems to be increased sensitivity to beta-endorphin in obesity. The possibility that endorphin abnormalities may be causal in obesity cannot be ruled out.
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PMID:A perspective on the hormonal abnormalities of obesity: are they cause or effect? 1635 9

Hypopituitarism is the partial or complete insufficiency of anterior pituitary hormone secretion and may result from pituitary or hypothalamic disease. The reported incidence (12-42 new cases per million per year) and prevalence (300-455 per million) is probably underestimated if its occurrence after brain injuries (30-70% of cases) is considered. Clinical manifestations depend on the extent of hormone deficiency and may be non specific, such as fatigue, hypotension, cold intolerance, or more indicative such as growth retardation or impotence and infertility in GH and gonadotropin deficiency, respectively.A number of inflammatory, granulomatous or neoplastic diseases as well as traumatic or radiation injuries involving the hypothalamic-pituitary region can lead to hypopituitarism. Several genetic defects are possible causes of syndromic and non syndromic isolated/multiple pituitary hormone deficiencies. Unexplained gonadal dysfunctions, developmental craniofacial abnormalities, newly discovered empty sella and previous pregnancy-associated hemorrhage or blood pressure changes may be associated with defective anterior pituitary function.The diagnosis of hypopituitarism relies on the measurement of basal and stimulated secretion of anterior pituitary hormones and of the hormones secreted by pituitary target glands. MR imaging of the hypothalamo-pituitary region may provide essential information. Genetic testing, when indicated, may be diagnostic.Secondary hypothyroidism is a rare disease. The biochemical diagnosis is suggested by low serum FT4 levels and inappropriately normal or low basal TSH levels that do not rise normally after TRH. L-thyroxine is the treatment of choice. Before starting replacement therapy, concomitant corticotropin deficiency should be excluded in order to avoid acute adrenal insufficiency. Prolactin deficiency is also very rare and generally occurs after global failure of pituitary function. Prolactin deficiency prevents lactation. Hypogonadotropic hypogonadism in males is characterized by low testosterone with low or normal LH and FSH serum concentrations and impaired spermatogenesis. Hyperprolactinemia as well as low sex hormone binding globulin concentrations enter the differential diagnosis. Irregular menses and amenorrhea with low serum estradiol concentration (<100 pmol/l) and normal or low gonadotropin concentrations are the typical features of hypogonadotropic hypogonadism in females. In post menopausal women, failure to detect high serum gonadotropin values is highly suggestive of the diagnosis. In males, replacement therapy with oral or injectable testosterone results in wide fluctuations of serum hormone levels. More recently developed transdermal testosterone preparations allow stable physiological serum testosterone levels. Pulsatile GnRH administration can be used to stimulate spermatogenesis in men and ovulation in women with GnRH deficiency and normal gonadotropin secretion. Gonadotropin administration is indicated in cases of gonadotropin deficiency or GnRH resistance but is also an option, in alternative to pulsatile GnRH, for patients with defective GnRH secretion.
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PMID:Hypopituitarism. 1707 46


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