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

A direct effect of growth hormone and/or prolactin on the growth of the pancreatic beta-cell has been proposed. This study assessed the presence of human growth hormone (hGH)-binding sites in male adult rat endocrine pancreas via quantitative autoradiography. The binding of 125I-labeled hGH was evaluated by receptor autoradiography on frozen-pancreas cryostat cut sections. The sections were incubated with 125I-hGH (10(-10) M) for 75 min at room temperature, and nonspecific binding was determined in the presence of excess native hGH (5 X 10(-7) M). The specificity of the binding was assessed in competition experiments with bovine GH and ovine prolactin. The autoradiograms were quantified with a computer-assisted image-processing system. The sections were then stained to visualize the endocrine islets. Nondiabetic control and streptozocin (STZ)-injected rats were used. Our results show that 1) there is specific binding of iodinated hGH in small areas of the pancreas, which appear as the Langerhans islets when the autoradiogram and the stained sections are superimposed; 2) the specificity of hGH binding in rat islets is lactogenic; 3) the density of the hGH-binding sites in the endocrine pancreas is estimated at 4.8 fmol/mg protein, with IC50 ranging from 0.98 to 2.50 nM; and 4) binding sites may be present on the beta-cell, because specific binding disappears in STZ-injected rats. In conclusion, by use of a quantitative autoradiographic technique, we provide evidence for the presence of lactogenic receptors on rat beta-cells.
Diabetes 1990 Sep
PMID:Demonstration of lactogenic receptors in rat endocrine pancreases by quantitative autoradiography. 216 98

We evaluated six patients in whom a diagnosis of Sheehan's syndrome had been made. The plasma levels of the following hormones were measured: basal thyroxine (T4), estradiol and cortisol; and also follicle-stimulating hormone (FSH), luteinizing hormone (LH), growth hormone (GH), thyrotropin (TSH), prolactin (PRL) and adrenocorticotropic hormone (ACTH), basally and after acute challenge with LH releasing hormone (LHRH), GRF (1-29)NH2 or insulin hypoglycemia, TSH releasing hormone (TRH) and lysine-8-vasopressin, respectively. Two patients underwent chronic LHRH stimulation by pulsatile subcutaneous administration with infusion pump. In 4 cases, computed tomography (CT) was performed although cranial X-ray study was normal. A severe and generalized pituitary involvement was found in all patients, 3 of whom had diabetes mellitus. Probably, more insidious cases go unnoticed. The presence of asymptomatic partial empty sella (ES) in all the CTs that were carried out raises the possibility that it is another evolutive feature of SS.
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PMID:[Relations between Sheehan's syndrome and empty sella turcica. A functional study apropos of 6 cases]. 217 69

Amniotic fluid concentrations of immunoreactive prolactin were measured during the third trimester in 184 diabetic gravidas and correlated with concurrent levels of prolactin in maternal plasma. Prolactin measurements concorded with previously published estimates in normal gravid women and averaged 825 +/- 32 ng/mL (mean +/- SEM) in amniotic fluid and 168 +/- 6.5 ng/mL in simultaneously sampled plasma. Cross-sectional and longitudinal analyses indicated that the prolactin levels in amniotic fluid of pregnant diabetics declined significantly between weeks 32 and 40 of gestation, whereas plasma levels did not change consistently during the same interval. Mean values for amniotic fluid prolactin did not correlate with simultaneous prolactin concentrations in plasma, nor with maternal age, clinical estimates of polyhydramnios, amniotic fluid creatinine content, or lecithin/sphingomyelin (L/S) ratios or subsequent birth weight of the offspring. Clear-cut correlations with overall maternal glucose regulation could not be demonstrated. However, subtle effects may be operative since amniotic fluid prolactin displayed weak but significant correlations with concurrent levels of maternal plasma glucose, and mean values for hemoglobin A1c (HbA1c) but not with mean values for fasting plasma glucose (FPG). Amniotic fluid prolactin concentrations were significantly greater in patients with pregestational diabetes (White classes C, D, and F) than in women with gestational diabetes mellitus (GDM) (our classes A1, A2, and B1). The differences could not be accounted for by differences in metabolic regulation, maternal age, or weights of these two populations.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Amniotic fluid prolactin in the third trimester of pregnancies complicated by gestational or pregestational diabetes mellitus. 219 93

We studied the mechanism of normal lactation, especially the roles of prolactin (PRL) and oxytocin (OXT) in the initiation of lactation, the lactation in the women complicated with endocrinological disorders, and medical therapies for stimulation and suppression of lactation. The level of serum PRL increases as pregnancy progresses, and reaches to a peak on the day of delivery. Despite high PRL level, milk secretion does not appear during pregnancy, because the sex steroid hormones suppress binding of PRL to the receptor in the mammary gland. The initiation of milk secretion in puerperal women seems to be closely related to an increase in PRL levels induced by adequate suckling. In the mechanism of suckling-induced PRL increase, OXT from posterior pituitary seems to have an important role. Furthermore, the poor response of PRL to suckling was due to insufficient stimulation to the nipples by suckling because the size of nipples were relatively small in these mothers. The other mechanism involved in lactation is suckling-induced OXT secretion. OXT stimulates milk ejection. Anxiety or fear may inhibit the OXT release. We demonstrated that the number of pulsatile release of OXT by nursing was significantly decreased by the psychological stress induced by mental calculation. In the puerperal women with prolactinomas after surgery, the serum PRL level did not increase during pregnancy and milk secretion in puerperium was poor. In the puerperal women with diabetes mellitus, milk secretion was also poor. One of the causes may be related to the low PRL response to suckling stimuli. PRL stimulates milk yield in the mammary gland, but is not commercially available.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Hormonal control of lactation]. 223 Apr 14

For an adequate interpretation of the significance of somatomedin levels in clinical conditions, a number of factors should be considered which may have an influence on the result. First of all, the heterogeneity of the somatomedins, both in their complexed form and after dissociation, should be considered. These forms have an unequal degree of cross-reactivity in different assay systems, while only the function of SM-C/IGF-I and, to a minor degree, of IGF-II have been established. Both are mitogenic and IGF-II has more insulin-like effects than does SM-C/IGF-I. Only the latter has been shown to increase length in dwarf mice. Somatomedins are produced in many tissues. This has led to the concept of autocrine or paracrine functions. The levels of SM-C/IGF-I increase with age, and there is a large increase during puberty, particularly when measured in the radioimmunoassay. In addition its level is influenced by growth hormone, to a minor degree by thyroid hormones, prolactin and perhaps by HCS and insulin. Finally, the nutritional and metabolic state of the patient is important: low values have been found in malnutrition, poorly regulated diabetes mellitus and insufficiency of the liver. Measuring somatomedins may be helpful for diagnosis and evaluation of the therapy of certain disorders, but the complexity of the regulation of their blood levels needs caution in the interpretation of results.
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PMID:[Somatomedins. Structure, physiology and clinical data]. 243 21

The purpose of the study was to evaluate some of the hormones in 20 patients with alcoholic cirrhosis. We investigated the diurnal rhythmicity of some of the hormones (cortisol, follicle-stimulating hormone-FSH, luteinizing hormone-LH, growth hormone-LH, prolactin-PRL) and basal serum concentrations of thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4) and testosterone, as well as gastrin and insulin, using provocative tests. Statistical analysis of the results obtained from the observed patients compared with controls, showed significantly lower concentrations of T3 (p less than 0.05), cortisol (p less than 0.05), testosterone (p less than 0.05) and FSH (p less than 0.05), and significantly higher (p less than 0.01) serum concentration of prolactin. Then, in the cirrhotic group the serum concentrations of gastrin and insulin increased significantly (p less than 0.01), together with the disorders of carbohydrate metabolism (impaired glucose tolerance and diabetes mellitus. The described disturbances of some of the observed hormones are complex, particularly in their relationship by which the clinical picture of the cirrhotic patients can be explained.
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PMID:[Hormone levels in patients with alcoholic liver cirrhosis]. 249 Sep 94

Of 210 women with galactorrhea 66.2% had normal prolactin serum levels. Only in 33.4% elevated prolactin levels could be found, 0.4% were hypoprolactinemic. The TRH-stimulation test detected latent hyperprolactinemia in 13.5% of the cases, showed a normal thyroid function in 81.5%, hypothyroidism in 13.9% and hyperthyroidism in 4.6% and this is considered to be a more valuable diagnostic tool than the MCP-test. Galactorrhea was associated with the following conditions: hyperprolactinemia (34.8%), menstrual disturbances (67.4%), post-pill amenorrhea (30.2%), mastalgia (30.2%), prolactinoma (18.6%), fibrocystic disease (11.6%), hirsutism (4.6%), diabetes mellitus (2.3%).
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PMID:[The value of hyperprolactinemia determination within the scope of galactorrhea]. 249 8

We experimented with a wide range of serum-free media to find the best one for culturing insulinoma cells from the Syrian golden hamster, cell line In-R1-I10. Optimum cell growth came with a mixture of equal proportions of Dulbecco's modified Eagle's medium and Ham's F-12, supplemented with 10(-6) M insulin, 10 micrograms/ml transferrin, and 10(-9) M triiodothyronine (what we labeled DF-ITT medium). In addition to testing different varieties of basal media, we also experimented with different concentrations of known stimulants of cell proliferation, including transferrin, ferrous sulfate, insulin, epidermal growth factor, triiodothyronine, hydrocortisone, monoethanolamine, prolactin, proteose peptone, and selenium. Cells cultured in DF-ITT medium grew as well as those in serum-containing medium for 94 consecutive generations. Their insulin secreting capacity was maintained. The substitution of epidermal growth factor (10 ng/ml) for the insulin did not reduce either the growth rate or the insulin secreting capacity of the culture cells.
Diabetes Res Clin Pract 1989 Jan 03
PMID:Serum-free culture of insulin-secreting clonal cells from a hamster insulinoma. 253 87

Untreated streptozocin-induced diabetic (STZ-D) rats have previously been shown to have significantly increased hypothalamic concentrations of neuropeptide Y (NPY), a regulatory peptide that powerfully stimulates eating and drinking and inhibits secretion of several pituitary hormones when injected centrally. Tissue NPY concentrations have been measured by radioimmunoassay in selected hypothalamic regions microdissected from fresh, unfixed brain slices to localize diabetes-associated NPY changes precisely within the hypothalamus. Significant (35-200%) increases in NPY concentrations (P less than .01 vs. matched nondiabetic controls) were found in specific hypothalamic regions between 3 and 14 wk after induction of STZ-D. These regions included the paraventricular and ventromedial nuclei and lateral hypothalamic area, major appetite-regulating areas that are sensitive to the hyperphagic and polydipsic actions of NPY. Increased NPYergic activity in these areas may, at least partly, drive the increased eating and drinking characteristic of STZ-D. NPY concentrations were also increased in the arcuate nucleus and medial preoptic area. Because both of these regions are important in modulating pituitary hormone secretion, local NPY increases may be involved in the impaired secretion of luteinizing hormone, thyroid-stimulating hormone, growth hormone, and prolactin known to occur in STZ-D. Our finding of NPY increases in specific hypothalamic nuclei associated with functional changes found in STZ-D suggests that this peptide may have a role in the altered metabolic and neuroendocrine regulation of the syndrome.
Diabetes 1989 Mar
PMID:Increased neuropeptide Y concentrations in specific hypothalamic regions of streptozocin-induced diabetic rats. 256 12

The mechanism of the suppression of an ethanol-inducible cytochrome P-450 (P-450DM/j) by pituitary hormone has been studied in rats. The hepatic content of P-450DM/j protein quantitated by Western blots was low but was 2-fold higher in male than female untreated rats (75 and 34 pmol/mg of protein, respectively). The content was increased 2.6-fold (male) and 5.6-fold (female) by hypophysectomy and the sex-related difference was abolished. Treatment of hypophysectomized rats with human growth hormone (hGH), but not with prolactin, reversed the increased amounts of P-450DM/j protein. The hGH-induced suppression was more effective with the continuous infusion than intermittent injection. The hepatic level of P-450DM/j mRNA, determined by the use of a 23-mer oligonucleotide probe, was also changed by hypophysectomy and/or hGH-treatment, largely in parallel with the changes in the content of P-450DM/j protein and microsomal p-nitrophenol and aniline hydroxylations. These results suggest that growth hormone exerts the suppressive effect on P-450DM/j through a somatogenic receptor-mediated process. In another growth hormone-depleted condition, diabetes, the hepatic level of P-450DM/j mRNA was also increased to a level similar to that in hypophysectomized rats, but the protein content was 2- to 3-fold higher in diabetic than hypophysectomized rats. These results indicate, in addition to the reduction of serum growth hormone level, the presence of another stimulatory factor, which acts translationally or posttranslationally in livers of diabetic rats. On the other hand, coordinate changes in the level of P-450DM/j protein and the mRNA in hypophysectomized rats indicate that growth hormone acts rather directly and suppresses the level of P-450DM/j mainly at a pretranslational step in rat livers.
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PMID:Suppression of hepatic levels of an ethanol-inducible P-450DM/j by growth hormone: relationship between the increased level of P-450DM/j and depletion of growth hormone in diabetes. 258 89


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