Evidence of a catecholaminergic mechanism controlling alpha-MSH content in hypothalamic areas

SCIMONELLI TN; MARUCCO M; CELIS ME

Asociación Latinoamericana de Ciencias Fisiológicas,

Año: 1992 vol. 42 p. 123 - 123

possible catecholaminergic regulation of hypothalamic alpha-melanocyte-stimulating hormone (alpha-MSH) has been investigated in male rats by an in vivo approach. The hormone was measured by radioimmunoassay in three hypothalamic regions: medial basal hypothalamus, preoptic hypothalamic area and dorsolateral hypothalamus. The tyrosine hydroxylase inhibitor alpha-methyl-para-tyrosine (300mg/kg) increased the hypothalamic alpha-MSH content in medial basal hypothalamus and preoptic hypothalamic area when it was measured at 22:00 h. Diethyldithiocarbamate (600mg/kg), which inhibits dopamine beta-hydroxylase, as well as 2-3-dichloromethylbenzylamide (25mg/kg), which acts on the phenylethanolamine-NCH3 transferase also increased the alpha-MSH content in the above mentioned discrete areas. The alpha-adrenoceptor antagonist phenoxybenzamine (15mg/kg), as well as the alpha 1-adrenoceptor antagonist prazosin (1.0mg/kg), also increased the hypothalamic alpha-MSH conte