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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine the role of prolactin in increasing junctional communication among islet beta-cells, we studied dye coupling in pancreatic islets exposed to elevated levels of prolactin in vivo and in vitro. Islets were isolated from rats immediately after lactation or from rats bearing mammosomatotropic tumors (MtTW15), conditions involving high levels of prolactin (either 5-fold or 1000-fold control levels, respectively). When beta-cells were microinjected with the gap junction permeant dye Lucifer yellow CH, the mean number of dye-coupled cells per injection was approximately 10-fold greater than in islets from virgin control rats. As a more direct test of the effects of prolactin on beta-cell coupling, islets isolated from virgin rats were treated for 90 min with 500 ng/ml rat prolactin in the presence of low glucose (2.8 mM) and were microinjected with dye. The mean number of dye-coupled cells per injection increased by 6.7-fold over controls with low glucose, demonstrating a direct effect of prolactin on beta-cell coupling. In vitro treatment with high glucose (16.7 mM) resulted in a 2.7-fold increase in dye-coupled cells per injection. We discuss the possible relationship between the effects of glucose and of prolactin on coupling.
Diabetes 1987 Oct
PMID:Prolactin enhances cell-to-cell communication among beta-cells in pancreatic islets. 330 80

17 patients with active acromegaly (7 of them had diabetes mellitus, too), 13 patients with type I diabetes mellitus and 20 healthy controls were examined. The residual beta-cell secretion was determined by venous Tolbutamide test and the insulin sensitivity was determined by euglycemic clamp-technique. A positive correlation was found between the growth hormone level and prolactin and the size of the basic insulin secretion. In acromegaly (with or without diabetes) the sensitivity of beta-cell apparatus towards the stimulant Tolbutamide is preserved but the insulin reserves are diminished. There exists a positive correlation between the growth hormone level and the degree of insulin resistance and between the increased prolactin level and the degree of insulin resistance in acromegalic patients.
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PMID:[Insulin secretion and action in acromegaly]. 332 80

The effect of improving diabetic control on secondary hypogonadotropic amenorrhea was investigated in patients with insulin-dependent diabetes mellitus (IDDM). Second, the hypothesis that increased central (hypothalamic) opiate inhibition may have been responsible for the suppression of gonadotropin-releasing hormone (GnRH) was tested by observing the effect of a four-hour naloxone infusion (1.4 mg/hour) on serum gonadotropin levels. All known causes of secondary amenorrhea were excluded before patients were eligible for the study. The median duration of amenorrhea was six years, and median body weight was 101 percent of ideal. After six months of improved metabolic control (n = 5) using intensified conventional therapy or continuous subcutaneous insulin infusion, the level of glycosylated hemoglobin dropped from 11.8 +/- 0.9 percent to 8.5 +/- 0.5 percent (p less than 0.005), and body weight increased from 60.5 +/- 1.8 kg to 64.7 +/- 1.4 kg (p less than 0.02). Menses did not, however, return in any patient. There was no significant change in serum levels of estradiol, progesterone, dihydroxyepiandrosterone, testosterone, prolactin, basal or GnRH-stimulated luteinizing hormone, or follicle-stimulating hormone. There was no change in the levels of luteinizing hormone or follicle-stimulating hormone during the naloxone infusion either during poor metabolic control or after six months of improved metabolic control. In conclusion, a form of secondary hypogonadotropic amenorrhea was identified in patients with IDDM that did not remit with sustained improvements in metabolic control. It did not appear to be mediated through increased central opiate tone.
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PMID:Hypogonadotropic secondary amenorrhea in diabetes: effects of central opiate blockade and improved metabolic control. 333 66

This study evaluated in pregnant women with diabetes mellitus (DM) the prolactin (PRL) concentration in amniotic fluid (A-PRL), the initial decidual PRL content (D-PRL), and the decidual PRL secretion (D-PRL-s) in vitro into isosmotic (315 mmol/kg), hyperosmotic (426 mmol/kg) and hyposmotic (252 mmol/kg) media. Decidual tissue was collected at term from 18 normal pregnancies and from 23 women with DM (White's classification: 7 of class A (without insulin treatment) and 16 of the classes B-F. Twelve of the women with DM had signs of hydramnion. Amniotic fluid specimens were collected from 52 normal pregnancies and 17 of the women with DM. No significant difference was found between normals and diabetics when D-PRL, D-PRL-s into isosmotic medium and A-PRL were compared. No trends could be detected when the insulin treated women were grouped according to White's classification. The increment of D-PRL-s into hyperosmotic medium was 15% in normals (p less than 0.001 compared with isosmotic medium), in the DM group 23% for the non-insulin-treated women (p less than 0.05 when compared with normals) and 25% for the insulin treated women (p less than 0.01). In normals the hyposmotic medium reduced D-PRL-s by secretion 19% (p less than 0.001 compared with isosmotic medium) but no significant difference was observed between normals and diabetic groups (p greater than 0.10). In the group of diabetics no significant difference was found in any of the PRL quantities investigated between those with and without hydramnion.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Amniotic fluid prolactin, decidual prolactin content and decidual prolactin secretion into hypo-, iso-, and sodium chloride hyperosmotic media in vitro in pregnant diabetics at term. 355 26

During a fourteen-month period, 497 men were evaluated for a primary complaint of erectile dysfunction. The initial evaluation consisted of a history taken in a conventional manner and supplemented by a patient-completed sexual function questionnaire, a physical examination, and serum testosterone, serum prolactin, and nocturnal penile tumescence studies. When appropriate, additional evaluations, including penile vascular studies, two-hour oral glucose tolerance tests, and psychiatric consultation were obtained. Abnormal glucose metabolism was present in 161 men (32%). Five men (1%) had insulin-dependent diabetes mellitus (IDDM), 80 men (16%) had noninsulin-dependent diabetes mellitus (NIDDM), 55 men (11.1%) had newly diagnosed noninsulin-dependent diabetes mellitus, and 21 men (4.2%) had impaired glucose tolerance tests. One hundred forty-seven of these men (91.3%) had organic pattern impotence, and 14 (8.7%) had psychogenic pattern impotence.
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PMID:Erectile dysfunction in men with diabetes mellitus. 357 82

Acanthosis nigricans is a marker for disorders of insulin action, endocrine abnormalities, and cancer of internal organs. To evaluate the clinical significance of this marker the systemic alterations and clinical features of 26 patients with acanthosis nigricans seen at two institutions were reviewed. Most subjects affected by acanthosis nigricans were female (20 patients), Caucasian (22 patients), in the third decade of life (13 patients), and overweight (24 patients greater than 120 percent ideal body weight). Gonadal disease, present in 17 patients, was expressed as polycystic ovary syndrome (11 cases), disorders of prolactin secretion (two cases, one with polycystic ovary syndrome), streak gonads (one case), and hypogonadism of the male (four cases). Thyroid disease and tinea versicolor were present in four patients each. Three patients were receiving insulin therapy for diabetes mellitus, and in two additional patients diabetes mellitus was detected during the diagnostic workup. All patients had elevated fasting insulin levels; most of them also had an exaggerated insulin response to a glucose load. Two of 18 patients tested had antibodies against the insulin receptor in the circulation. Skin biopsy of acanthosis nigricans lesions from all 26 patients showed a typical pattern of hyperkeratosis, acanthosis, and epidermal papillomatosis. Colloidal iron staining showed glycosaminoglycan infiltration of the papillary dermis (21 of 21 cases), consisting mainly of hyaluronic acid. It is concluded that: (1) hyperinsulinenemia and local dermal glycosaminoglycan deposition are regular features in acanthosis nigricans and (2) patients with acanthosis nigricans should be screened for diabetes mellitus, gonadal disease, and hypothyroidism.
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PMID:Spectrum of endocrine abnormalities associated with acanthosis nigricans. 367 58

Plasma zinc and pituitary and testicular hormone concentrations were measured in two groups of male adolescents. One group comprised insulin-dependent diabetes mellitus patients, aged 14-19 years; the other, as control, included 12 healthy youngsters aged 13-19 years. Plasma concentration of zinc, prolactin, testosterone, and dihydrotestosterone were lower in diabetics than in controls, whereas the ratios of androstenedione and androstenedione to testosterone + dihydrotestosterone were higher. Plasma FSH and LH were normal. These results suggest a diminished conversion of androstenedione to testosterone and relate zinc with the 17-beta-hydroxysteroid dehydrogenase enzyme activity.
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PMID:Low plasma zinc and androgen in insulin-dependent diabetes mellitus. 374 Oct 26

Infertility associated with anovulation and loss of regular oestrous cyclicity is a consequence of diabetes mellitus in the rat. In an attempt to define loci of altered function, studies were undertaken to examine various aspects of hypothalamic-pituitary function in rats treated with streptozotocin. Medial basal hypothalamic fragments from adult female diabetic rats contained the same amount of gonadotrophin-releasing hormone but, with depolarization, released slightly but insignificantly (p greater than 0.05) more than did those from control animals. Furthermore, release of luteinizing hormone from pituitaries exposed to hypothalamic gonadotrophin-releasing hormone was not altered by diabetes. Removal of the negative feedback effect of gonadal steroids upon the hypothalamic-pituitary axis produced an increase in luteinizing hormone and follicle stimulating hormone concentrations in the serum of normal rats within 6h (p less than 0.05), whereas 24h were required for similar increases in diabetic rats. However, the same concentrations of gonadotrophins were found in diabetic and control animals 120 h after ovariectomy. The inhibitory action of oestradiol benzoate on the secretion of gonadotrophins was more pronounced in ovariectomized diabetic than in control rats. A 74% depression in serum luteinizing hormone (p less than 0.01) was produced by 0.5 microgram oestradiol benzoate per day in diabetic rats, while 5 micrograms was required in control animals. Similar reductions in follicle stimulating hormone concentrations (50%, p less than 0.05) were obtained by injecting 5 micrograms of the oestrogen into diabetic or 50 micrograms into control rats. Increases in serum prolactin were greater in the control animals however.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Altered hypothalamic-pituitary function in the adult female rat with streptozotocin-induced diabetes. 392 97

The present study examined the effects of streptozotocin-induced diabetes on prolactin (Prl) secretion and its correlation with estrogen receptor levels in the anterior pituitary and hypothalamus. Prl was measured in adult ovariectomized rats and after estradiol treatment (10 micrograms estradiol benzoate (Eb) 48, 24 and 1 h before experiments) or acute TRH administration (4 micrograms/kg body weight). Substantial decreases in estradiol- and TRH-induced Prl release were observed in diabetic rats. Insulin therapy was able to restore this response. Measurement of nuclear estradiol receptors by exchange assay in the pituitary of Eb-treated rats revealed a significant reduction in receptor levels in the diabetic group and a restoration to normal values in insulin-treated diabetic rats. Similar results were obtained by measuring total pituitary receptor content (cytosolic plus nuclear receptors). No significant changes were observed in nuclear hypothalamic estradiol receptors. However, the number of total hypothalamic estradiol receptors was diminished in diabetic rats although the translocation was proportionally greater in these animals. These results indicate that the disrupted reproductive functions described in streptozotocin diabetic rats may be due, at least in part, to deficiencies in Prl secretion and pituitary estradiol action.
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PMID:Alterations in the prolactin secretion in streptozotocin-induced diabetic rats. Correlation with pituitary and hypothalamus estradiol receptors. 393 99

We recently investigated two patients with diabetes and elevated serum prolactin levels in whom no cause of hyperprolactinaemia could be found. For this reason we measured fasting serum prolactin levels in 72 diabetic males and compared the results with those of 63 healthy males and 90 nondiabetic males attending an Impotence Clinic. The diabetic group had significantly higher serum prolactin levels (13.1 +/- 0.9 ng/ml) than the two control groups (9.9 +/- 0.6 ng/ml for normal males and 7.7 +/- 0.3 ng/ml for the non-diabetic impotent group). Eighteen percent of the diabetics studied had serum prolactin levels above the normal range for males (greater than 20 ng/ml). There was no correlation between serum prolactin levels and duration of diabetes, glycosylated haemoglobin level or presence of clinically apparent retinopathy. The correlation between serum prolactin level and fasting plasma glucose was weak though statistically significant (r = 0.26, P less than 0.05).
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PMID:Hyperprolactinaemia in male diabetics. 399 96


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