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)

Traditional nomadic hunter-gatherer societies have long birth intervals of at least 4 years brought about by the contraceptive effect of extended lactation. In some developing countries, lactational infertility continues to prevent more births than any of the modern contraceptives. Afferent neural inputs from nipple stimulation are conveyed through the spinal cord to the hypothalamus. These inputs stimulate the local release of beta-endorphin, which in turn inhibits hypothalamic secretion of gonadotrophin releasing hormone, thereby suppressing secretion of luteinizing hormone from the pituitary, ovarian follicular development, ovulation, and menstruation. Beta-endorphin release also suppresses dopamine secretion, thereby stimulating prolactin secretion. The more infants suckle, the more beta-endorphin circulates, which increases the duration of lactational amenorrhea. The 1st postpartum menstruation almost always occurs before the 1st ovulation during the first 6 months postpartum. In breast-feeding women who still have amenorrhea after 6 months postpartum, 1st ovulation tends to occur before 1st menstruation. Irrespective of maternal nutritional status or the time the infant was first introduced to supplemental foods, lactational amenorrhea protects 98% of breast-feeding women against pregnancy during the first 6 months postpartum. Prolonged lactational amenorrhea may afford women who breast feed 1-2 years good contraceptive protection. In developed and developing countries, women should exclusively breast feed their infants for the first 6 months, and if they have not yet experienced menstruation, they do not need to use contraception. After 6 months, they should supplement lactational amenorrhea with a contraceptive to prevent pregnancy and to achieve at least a 2-year interval between births. The appearance of the first tooth is a signal for supplementing with other food.
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PMID:Lactational infertility in family planning. 848 57

Human semen contains large amounts of opioid peptides and cytokines. We have measured the concentrations of interleukin (IL)-6 in 140 semen samples and of beta-endorphin in 77 semen samples. The median concentration of beta-endorphin in seminal plasma from normozoospermic men (n = 23) was 154.7 pg/ml (10th-90th percentiles, 42.0-774.6), and there was no significant difference in the beta-endorphin concentration among normozoospermic, oligozoospermic (n = 28), asthenozoospermic (n = 15), azoospermic (n = 4) and post-vasectomy (n = 7) samples. There was no correlation between beta-endorphin concentration and sperm characteristics, nor with blood hormones. beta-Endorphin concentration was lower in cases with immunological infertility, as revealed by a positive direct mixed antiglobulin reaction test (n = 12) (P < 0.01), than in matched controls. The median concentration of IL-6 in samples with normal sperm concentration, motility and morphology with or without white blood cells (n = 39) was 26.1 pg/ml (10th-90th percentiles, 7.3-172.3), and there was no significant difference in the IL-6 concentration among normozoospermic, oligozoospermic (n = 46), asthenozoospermic (n = 32), azoospermic (n = 13) and post-vasectomy (n = 10) samples. The IL-6 concentration was significantly higher in cases of varicocele (n = 22) without white blood cells in semen (P < 0.001) than in matched controls without varicocele (n = 23). In addition, the IL-6 concentration was elevated (P < 0.0001) in cases with accessory sex gland inflammation (n = 40). IL-6 concentration was positively correlated with white blood cells in semen (n = 60, r = 0.59, P < 0.0001), but there was no correlation with beta-endorphin concentration. The IL-6 concentration chosen to differentiate between cases with and without accessory gland inflammation was 45.3 pg/ml, with a specificity of 80.6% and a sensitivity of 92.5%. It is concluded that beta-endorphin in seminal plasma plays an immune suppressive role, and that increased IL-6 concentration may be related to testicular dysfunction in cases with varicocele. Furthermore, IL-6 is an accurate marker of accessory sex gland inflammation.
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PMID:Evaluation of beta-endorphin and interleukin-6 in seminal plasma of patients with certain andrological diseases. 882 35

The effect of VIP on mast cell invasion/degranulation in testicular interstitium of stressed (immobilization and cold) and beta-endorphin-treated rats were investigated. Fifty-three Wistar male rats were used in four series of experiments. Initially, the effect of immobilization and cold stress on mast cell invasion and degranulation in testicular interstitium was examined in three age group of rats: 15 (n = 6), 30 (n = 6), and 45 (n = 7) days of age. Five animals per age group were used as controls. Because the most obvious effect of the stress on mast cell invasion/degranulation in testicular interstitium was observed in 45-day-old rats, the action of VIP in stressed and beta-endorphin-treated rats was only investigated at this age group. Mast cells and Leydig cells were evaluated by using histochemical and light microscopic protocols. Stress caused mast cell accumulation and degranulation in the testicular interstitium. Stress decreased heparin synthesis and possibly increased histamine content of mast cells. The effect of beta-endorphin was not as high as seen with stress. In some areas of testicular interstitium of stressed rats, there were aplasic and/or inactive Leydig cells. VIP inhibited proliferation and degranulation of mast cells, increased heparin content of the cells, and protected Leydig cells. By way of mast cell accumulation and degranulation in the testicular interstitium, exposure to stress may lead to Leydig cell damage and infertility. VIP may be involved in the protection of normal testicular function under stress conditions.
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PMID:The effect of vasoactive intestinal peptide (VIP) on mast cell invasion/degranulation in testicular interstitium of immobilized + cold stressed and beta-endorphin-treated rats. 884 72

A proposed mechanism for sorting secretory proteins into granules for release via the regulated secretory pathway in endocrine-neuroendocrine cells involves binding the proteins to a sorting receptor at the trans-Golgi network, followed by budding and granule formation. We have identified such a sorting receptor as membrane-associated carboxypeptidase E (CPE) in pituitary Golgi-enriched and secretory granule membranes. CPE specifically bound regulated secretory pathway proteins, including prohormones, but not constitutively secreted proteins. We show that in the Cpe(fat) mutant mouse lacking CPE, the pituitary prohormone, pro-opiomelanocortin, was missorted to the constitutive pathway and secreted in an unregulated manner. Thus, obliteration of CPE, the sorting receptor, leads to multiple endocrine disorders in these genetically defective mice, including hyperproinsulinemia and infertility.
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PMID:Carboxypeptidase E is a regulated secretory pathway sorting receptor: genetic obliteration leads to endocrine disorders in Cpe(fat) mice. 901 8

Cpefat mice carry a mutation in the carboxypeptidase E/H gene which encodes an exopeptidase that removes C-terminal basic residues from endoproteolytically cleaved hormone intermediates. These mice have endocrine disorders including obesity, infertility, and hyperproinsulinemia-diabetes syndrome, but the etiology remains an enigma. Because studies have identified membrane carboxypeptidase E as a sorting receptor for targeting prohormones to the regulated secretory pathway for processing and secretion, the intracellular routing and secretion of pro-opiomelanocortin/adrenocorticotropin and growth hormone from anterior pituitary cells were investigated in Cpefat mice. In Cpefat mice, pro-opiomelanocortin was accumulated 24-fold above normal animals in the pituitary and it was poorly processed to adrenocorticotropin. Furthermore, pro-opiomelanocortin was secreted constitutively at high levels, showing no response to stimulation by corticotropin-releasing hormone. Similarly, growth hormone release was constitutive and did not respond to high K+ stimulation. Both pro-opiomelanocortin and growth hormone levels were elevated in the circulation of Cpefat mice versus normal mice. These data provide evidence that the lack of carboxypeptidase E, the sorting receptor, results in the intracellular misrouting and secretion of pro-opiomelanocortin and growth hormone via the constitutive pathway in the pituitary of Cpefat mice.
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PMID:Intracellular misrouting and abnormal secretion of adrenocorticotropin and growth hormone in cpefat mice associated with a carboxypeptidase E mutation. 914 34

To evaluate the late-effects of allogeneic bone marrow transplantation (BMT) on endocrine function 20 adults (10 females, 10 males) with hematological malignancies were studied after a mean of 3.2 years (range 1.0-10.0) following BMT. The mean age of patients at the time of BMT was 39 years. Dynamic tests of the hypothalamic-pituitary axis included growth hormone releasing hormone (GHRH), gonadotropin releasing hormone (GnRH) and thyrotropin releasing hormone (TRH) stimulations with measurements of serum growth hormone (GH), follicle stimulating hormone (FSH), luteinizing hormone (LH), thyrotropin (TSH) and prolactin (PRL) responses. Adrenal function was assessed with the adrenocorticotropin (ACTH) test. Five patients (25%) had a subnormal GH response to GHRH stimulation, but all had a normal serum insulin-like growth factor I (IGF-I) value. There was an inverse nonlinear relationship between the body mass index (BMI; kg/m2) and GH response but no relation between the GH response and total body irradiation (TBI), intrathecal treatment or occurrence of graft-versus-host disease. In females, serum FSH and LH basal levels and responses to GnRH, in spite of oestrogen substitution therapy in 9/10 patients, indicated ovarian failure and early menopause. Most responses to GnRH were delayed. All males had elevated serum basal FSH levels indicating damage in seminiferous tubulus and infertility. Serum basal LH was elevated only in four males but testosterone values were all within normal limits. However, the mean free androgen index (FAI) was in the low normal range, and two subjects had abnormally low FAI. Serum free thyroxine (fT4) levels were normal in all but one, but an exaggerated TSH response to TRH occurred in seven patients (35%). Four of them had received TBI and one total nodal irradiation suggesting radiation-induced damage to the thyroid gland. In 19 of the 20 patients, adrenal function judged with ACTH test was normal. We conclude that functional impairments of the hypothalamus-pituitary-gonad/thyroid axis are common while disturbances in GH, adrenal and prolactin occur less often in patients after intensive treatment and BMT. Typically, the target organ is more commonly affected than the hypothalamus-pituitary axis. In spite of normal serum testosterone and LH values, serum FAI may reveal androgen deficiency.
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PMID:Long-term effects of allogeneic bone marrow transplantation (BMT) on pituitary, gonad, thyroid and adrenal function in adults. 972 67

Galanin is a pleiotropic neuroendocrine signal produced in discrete subpopulations of neurons distributed in several sites in the hypothalamus. Neuropeptide Y and beta-endorphin also display pleiotropism, but they are produced by subpopulations of neurons located only in the arcuate nucleus of the hypothalamus. Each of these neuropeptides exerts a regulatory influence on reproduction and appetitive behavior. Experimental and morphologic evidence from our laboratory show direct contacts and interplay among these diverse signals. Seemingly, an interconnected network composed of these three neuropeptide-producing neurons provides precision and site specificity in the relay of information necessary to govern reproduction and appetite. Disruptions in this interplay are likely to manifest in untoward consequences such as infertility and obesity.
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PMID:Neuroendocrine interactions between galanin, opioids, and neuropeptide Y in the control of reproduction and appetite. 992 74

There are reports on some patients with clearly manifested specific features of genotype and phenotype similar to those of ob/ob and db/db mice. Three patients from Turkey were described who had a homozygous mutation in the gene of leptin identical to the mutation in C57BL6J ob/ob mice. This mutation is a C --> T substitution in codon 105 of the amino acid sequence of leptin. In mice this mutation generates a stop-codon; in humans it substitutes Arg-105 with Trp. The mutant human leptin cannot be secreted by the cells and thus has no effect on the hypothalamus. Patients with a homozygous mutation of the leptin receptor resulting in the G --> T substitution in the splice donor site of exon 16 were studied in a family of Kabilian origin. Exon 16 was not included in the mature mRNA molecule, and a truncated leptin receptor was synthesized which lacked the transmembrane and intracellular domains; this receptor was unable to transduce the hormonal signal. Both groups of patients suffered from obesity, delayed linear growth, infertility, increased blood insulin level, and other disorders. Leptin influences lipid metabolism by stimulating the expression of the proopiomelanocortin (POMC) gene in melanocortinergic neurons of the hypothalamus. POMC is the precursor of alpha-melanocyte-stimulating hormone (alpha-MSH), which binds to the melanocortin receptor MC4-R in the brain, decreases appetite, and activates lipid metabolism. Patients with mutations in MC4-R suffered only from obesity, but their growth and puberty were not affected. Thus, leptin apparently stimulates growth and puberty not through its binding to the receptors on melanocortinergic neurons, but through its binding to receptors on other hypothalamic neurons; this effect of leptin is not affected by mutations in the MC4-R gene.
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PMID:Adipose tissue as an endocrine organ regulating growth, puberty, and other physiological functions. 1039 72

Congenital adrenal hyperplasia describes a group of inherited autosomal recessive disorders characterized by an enzymatic defect in cortisol biosynthesis, compensatory increases in corticotropin secretion, and adrenocortical hyperplasia. 21-Hydroxylase deficiency is responsible for more than 95% of cases and is one of the most common known autosomal recessive disorders. The classic or severe type presents in the newborn period or early childhood with virilization and adrenal insufficiency, with or without salt loss; the mild or nonclassic form presents in late childhood or early adulthood with mild hyperandrogenism and is an important cause of masculinization and infertility in women. This wide range of phenotypic expression is mostly explained by genetic variation, although genotype-phenotype discrepancies have been described. Reproductive, metabolic, and other comorbid conditions, including risk for tumors, are currently under investigation in both forms of the disease. A high proportion of patients with adrenal incidentalomas may be homozygous or heterozygous for 21-hydroxylase deficiency. Women with congenital adrenal hyperplasia often develop the polycystic ovary syndrome. Ectopic adrenal rest tissue is often found in the testes of men with congenital adrenal hyperplasia; characteristic clinical and radiologic findings help differentiate this tissue from other tumors. Levels of corticotropin-releasing hormone are elevated in patients with depression and anxiety and are expected to be elevated in patients with congenital adrenal hyperplasia; it is unknown whether patients with 21-hydroxylase deficiency have an increased incidence of these psychiatric disorders. Abnormalities in both the structure and function of the adrenal medulla have been shown in patients with classic congenital adrenal hyperplasia, and the degree of adrenomedullary impairment may be a biomarker of disease severity. The 21-hydroxylase-deficient mouse has provided a useful model with which to examine disease mechanisms and test new therapeutic interventions in classic disease, including gene therapy. Treatment of this condition is intended to reduce excessive corticotropin secretion and replace both glucocorticoids and mineralocorticoids. However, clinical management is often complicated by inadequately treated hyperandrogenism, iatrogenic hypercortisolism, or both. New treatment approaches currently under investigation include combination therapy to block androgen action and inhibit estrogen production, and bilateral adrenalectomy in the most severely affected patients. Other approaches, which are in a preclinical stage of investigation, include treatment with a corticotropin-releasing hormone antagonist and gene therapy.
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PMID:NIH conference. Future directions in the study and management of congenital adrenal hyperplasia due to 21-hydroxylase deficiency. 1184 30

Natural selection has linked the physiological controls of energy balance and fertility such that reproduction is deferred during lean times, particularly in female mammals. In this way, an energetically costly process is confined to periods when sufficient food is available to support pregnancy and lactation. Even in the face of abundance, nutritional infertility ensues if energy intake fails to keep pace with expenditure. A working hypothesis is proposed in which any activity or condition that limits the availability of oxidizable fuels (e.g., undereating, excessive energy expenditure, diabetes mellitus) can inhibit both gonadotropin-releasing hormone (GnRH)/luteinizing hormone secretion and female copulatory behaviors. Decreases in metabolic fuel availability appear to be detected by cells in the caudal hindbrain. Hindbrain neurons producing neuropeptide Y (NPY) and catecholamines (CA) then project to the forebrain where they contact GnRH neurons both directly and also indirectly via corticotropin-releasing hormone (CRH) neurons to inhibit GnRH secretion. In the case of estrous behavior, the best available evidence suggests that the inhibitory NPY/CA system acts primarily via CRH or urocortin projections to various forebrain loci that control sexual receptivity. Disruption of these signaling processes allows normal reproduction to proceed in the face of energetic deficits, indicating that the circuitry responds to energy deficits and that no signal is necessary to indicate that there is an adequate energy supply. While there is a large body of evidence to support this hypothesis, the data do not exclude nutritional inhibition of reproduction by other pathways and processes, and the full story will undoubtedly be more complex than this.
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PMID:Neuroendocrinology of nutritional infertility. 1552 98


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