Interacction of alpha-MSH and noradrenaline in the median eminence in the control of female sexual behaviour

SCIMONELLI TN; MEDINA F; WILSON C; CELIS ME

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 1999 p. 219 - 219

n the present study, we examined the effects of the injection of a-melanotropin (a-MSH), noradrenaline (NA), and dopamine in the median eminence of ovariectomized-adrenalectomized rats on female sexual behavior. The animals were primed with l0 mg of estradiol benzoate, and 52?54 h later they were injected into the median eminence with either 1 ml of artificial  cerebrospinal fluid, 1ug/rat a-MSH, 200 ng/rat NA, 200 ng or 2 ug/rat dopamine, in 1 ul of artificial cerebrospinal fluid. Both a-MSH and NA significantly stimulated sexual behavior. This effect was antagonized by two b-adrenergic antagonists: propranolol (500 ng/rat) and metoprolol (400 ng/rat) applied 15 min before the a-MSH or NA. The a-adrenergic antagonist prazosine (500 ng/rat) was ineffective in reducing the effect of a-MSH. The vehicle and dopamine at both doses had no effect on sexual activity. These results indicate that a-MSH and NA in the medianeminence stimulate female sexual behavior and that NA mediate