Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0848255 (female puberty)
 121 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mice homozygous for targeted disruption of the GH receptor/GH binding protein gene (GH-R-KO mice; -/-) exhibit reduced plasma IGF-I levels, elevated plasma GH levels, and dwarf phenotype. Although most GH-R-KO mice are fertile, age at first conception is greatly delayed in -/- x -/- matings. Here we report that the age of vaginal opening is significantly delayed in GH-R-KO vs. normal mice, but it can be advanced by treatment with recombinant human (rh)IGF-I. In pregnant GH-R-KO females, fetal size is reduced and pregnancy is prolonged while placental weight is, unexpectedly, increased. Alterations in fetal and placental weight are related to maternal rather than fetal genotype. Moreover, litter size and body weight of newborn pups are significantly reduced in GH-R-KO vs. normal females. Reduction in litter size reflects both dam and sire effects. We conclude that GH resistance and consequent reduction in peripheral IGF-I levels is associated with delay of female puberty, alterations in fetal and placental growth, delay of parturition, and reduced litter size.
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PMID:Deficits in female reproductive function in GH-R-KO mice; role of IGF-I. 1034 52

The importance of leptin in regulating sexual maturation is supported by data showing that deletions of the leptin gene or alterations in the leptin receptor result in infertility. However, attempts to define a role for leptin in normal puberty have produced equivocal results, leading to the conclusion that, if leptin is involved in puberty, its role is permissive and not obligatory. To better define the importance of leptin in primate puberty, the present study tested the hypothesis that a premature elevation in nocturnal leptin concentrations would accelerate indices of puberty, including nocturnal LH secretion in female rhesus monkeys (Macaca mulatta). Juvenile, gonadally intact females were treated daily with leptin (n = 6; 30 micro g/kg, sc at 1700 h) from 12-30 months of age and were compared with age-matched control females (n = 13). Chronic elevation in peripheral concentrations of leptin increased serum levels of both daytime and nighttime bioactive LH at a significantly younger age compared with control females. The earlier rise in LH in leptin-treated females was associated with an earlier increase in serum estradiol and occurrence of menarche. Despite this effect of leptin, nocturnal serum LH was significantly higher at each age assessed in non-leptin-treated ovariectomized controls (n = 6). In addition, leptin increased skeletal lengths and maturity that were associated with significantly higher serum levels of nocturnal GH and daytime IGF-I. Although body weights were not consistently affected by treatment, body mass index, as an index of body fat, was consistently lower in leptin-treated females. Taken together, these data indicate that the chronic elevation in serum leptin concentrations advances the nocturnal increase in serum LH as well as other parameters of female puberty. Furthermore, the observation that nocturnal LH was higher in age-matched, agonadal females compared with the leptin-treated females suggests that the nongonadal drive to LH secretion is operative in female macaques as early as 14 months of age, suggesting that the effect of leptin on puberty in female primates may involve a diminution in gonadal negative feedback suppression of LH secretion. Such a role would suggest that leptin is permissive yet critical for advancing female puberty.
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PMID:Leptin administration increases nocturnal concentrations of luteinizing hormone and growth hormone in juvenile female rhesus monkeys. 1455 68