Effect of the gonadectomy and the reposition of gonadal steroids on alpha-MSH concentration in discrete hypothalamic areas during a 24 hours period.

SCIMONELLI TN; CELIS ME

KARGER

Año: 1987 vol. 45 p. 441 - 441

ypothalamic alpha-melanocyte-stimulating hormone (alpha-MSH) was measured by radioimmunoassay in males after orchidectomy and after orchidectomy plus testosterone replacement, and in females after ovariectomy and after ovariectomy plus estradiol or progesterone, or estradiol and progesterone (EP) replacement. Gonadectomy inverted the diurnal rhythm of the alpha-MSH content observed in intact males in the medial basal hypothalamus (MBH) and preoptic hypothalamic area (POA), and produced a notable decrease of alpha-MSH total content in the three regions studied (MBH, POA and dorsolateral hypothalamus, DLH). The addition of testosterone restored the rhythm of the intact males and increased alpha-MSH content in MBH and POA. No diurnal variations in alpha-MSH content were observed in ovariectomized females. A circadian rhythm similar to that of proestrus was observed in MBH after estradiol or EP replacement, and in POA after the addition of any steroid. In DLH t