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M Lage

Publications and source records attributed to M Lage.

22 records · Page 2Linked to original sources
PubMed1997

Sex-based differences in serum leptin concentrations from umbilical cord blood at delivery.

Sex-based differences in serum leptin concentrations have been reported in adolescence and adulthood. To discover when such differences were generated, serum leptin concentrations were measured in umbilical cord blood from 46 healthy infants and in the mother's blood at delivery. Considering the respective body weights of the mothers and infants (68.5 +/- 1.3 kg and 3.3 +/- 0.0 kg), umbilical cord concentrations of leptin were disproportionately high in the infants (9.4 +/- 1.2 micrograms/l) compared with those in the mothers (18.7 +/- 1.3 micrograms/l). There was a wide variation in the infants leptin values (1.2 +/- 56.8 micrograms/l) that did not correlate with height, weight, cephalic circumference, or any other growth-related parameter. The most striking differences emerged when results were analysed by sex: umbilical cord concentrations of leptin in the girls (12.9 +/- 2.2 micrograms/l) were significantly (P < 0.01) greater than those in the boys (6.8 +/- 0.9 micrograms/l), although no differences in leptin concentrations were observed between the mothers who gave birth to a girl (19.5 +/- 2.2 micrograms/l) and those who gave birth to a boy (18.1 +/- 1.7 micrograms/l). The sex-based differences were not attributable to any growth-related differences between the sexes, except heavier placental weights in the girls (P < 0.007) than in the boys. These differences in leptin concentrations may reflect a sex-based difference in the regulation of leptin production by the fetal adipose tissue.

Adult↗
PubMed1991

[Lack of effect of the administration of TRH on growth hormone secretion induced by dexamethasone].

The usually accepted effect of corticosteroids on growth hormone secretion (GH) is the reduction or blockage of secretion. Our laboratory has previously reported that corticosteroids could have an acute stimulatory effect on this secretion; we have now studied the effect of administering THR on corticosteroids induced GH secretion. Three stimulatory tests were performed to three healthy volunteers on different days. Saline administration on time 0 and time 120 minutes (control test) did not modify GH levels. On the contrary, the administration of 4 mg Dexamethasone i.v. on time 0 induced an increase in GH with a maximum peak of 10 = 3.3 micrograms/L after three hours being these differences statistically significant (p less than 0.05) when referred to the control test from 120 to 240 minutes. The corticosteroid GH stimulus presented a peculiar secretion pattern: During two hours there were no changes in basal values and afterwards the values were maintained in maximum peak values during two hours, with a great net release of GH. The administration of THR (400 micrograms iv) 120 minutes after the administration of Dexamethasone did not notify GH secretion pattern when compared with the group receiving only Dexamethasone. To conclude, the administration of corticosteroids is a new and peculiar stimulus for GH secretion. Lack of THR inhibitory function suggests that the corticosteroid stimulatory function is probably at the hypothalamus level.

Adult↗
PubMedDate not supplied

[Role of ghrelin in the pathophysiology of eating behaviour].

Ghrelin, the endogenous ligand for GHS-R, was isolated from rat stomach, although other tissues exist expressing ghrelin, such as pituitary, hypothalamus, placent, ovary, testes, etc. It was showed that ghrelin is implicated in GH secretion, in vivo and in vitro. There are direct evidences that proof that ghrelin administration induces GH secretion. There are in vivo data, showing ghrelin as a most potent GH secretor than GHRH. Evidences exist of ghrelin actions in the regulation of food intake and energy homeostasis. Ghrelin has a clear role in the differents pathologies such as obesity, anorexia and bulimia.

Agouti-Related Protein↗