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)

The present experiments were undertaken to throw light on the physiological role played by alpha-MSH in the advent of female puberty. The serum and pituitary alpha-MSH concentrations were determined in prepubertal rats 5, 15, 25, 30, 33 days old and at vaginal opening. The serum levels showed a significant increase on day 30 and the pituitary alpha-MSH levels increased steadily from day 5 to day 33. To determine if a relation exists between the increase in alpha-MSH levels and the peak of LH prior to vaginal opening, prepubertal rats of the same age range as above received an injection of alpha-MSH or saline solution and were sacrificed 30 min later. The peptide increased LH serum levels only at 30 days of age. To examine the hypothesis that alpha-MSH was involved in determining the timing of puberty, prepubertal rats pretreated with estradiol benzoate received an injection of alpha-MSH or saline solution on day 28. This treatment advanced the time of vaginal opening by 2 days in the experimental animals. With the same experimental procedure, an increase in serum levels of LH and progesterone was also observed at 29 days of age. The action of alpha-MSH on GnRH was analysed by incubating median eminence from prepubertal rats 20, 25 and 30 days of age, with the peptide, alpha-MSH increased GnRH release only in 25-day-old rats. The above results show that acute treatment with alpha-MSH induces modifications in the hormones related to puberty and hence allows us to include alpha-MSH in the chain of neuroendocrine events involved in reproductive maturation.
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PMID:Acute administration of alpha-melanotropin exerts a stimulatory control on puberty. 254 77

A growing body of research on humans suggests that exposure to a stressful family environment or father absence from home during childhood is associated with early female puberty and greater interest in infants among adolescent girls. This effect may be mediated by early exposure to harsh and inconsistent maternal care, but the mechanisms by which maternal care affects female reproductive maturation are not known. The present study reports sex differences in interest in infants among juvenile rhesus macaques similar to those observed in human adolescents. Furthermore, juvenile females that were exposed to harsh and inconsistent maternal care in infancy showed higher interest in infants than controls. Evidence from cross-fostered females indicated that these effects resulted from early experience and not genetic inheritance from the mother. There were no significant differences in female age at first conception in relation to the quality of maternal care received during infancy. Macaque females exposed to harsh and inconsistent maternal care in infancy tended to have higher cortisol responses to stress and to corticotropin-releasing hormone than controls in the first three years of life. Furthermore, females with higher cortisol responses to stress exhibited higher interest in infants. These findings suggest that some of the effects of early parental care on female reproductive maturation may be mediated by developmental changes in the activity of the hypothalamic-pituitary-adrenal axis.
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PMID:Effects of early experience on female behavioural and reproductive development in rhesus macaques. 1602 88