Resumen

SILVEIRA, N.A.  y  FRANCI, C.R.. Antisense mRNA for NPY-Y₁ receptor in the medial preoptic area increases prolactin secretion. Braz J Med Biol Res [online]. 1999, vol.32, n.9, pp. 1161-1165. ISSN 1414-431X.  http://dx.doi.org/10.1590/S0100-879X1999000900016.

We investigated the participation of neuropeptide Y-Y₁ receptors within the medial preoptic area in luteinizing hormone, follicle-stimulating hormone and prolactin release. Four bilateral microinjections of sense (control) or antisense 18-base oligonucleotides of messenger ribonucleic acid (mRNA) (250 ng) corresponding to the NH₂-terminus of the neuropeptide Y₁ receptor were performed at 12-h intervals for two days into the medial preoptic area of ovariectomized Wistar rats (N = 16), weighing 180 to 200 g, treated with estrogen (50 µg) and progesterone (25 mg) two days before the experiments between 8.00 and 10:00 a.m. Blockade of Y₁ receptor synthesis in the medial preoptic area by the antisense mRNA did not change plasma luteinizing hormone or follicle-stimulating hormone but did increase prolactin from 19.6 ± 5.9 ng/ml in the sense group to 52.9 ± 9.6 ng/ml in the antisense group. The plasma hormones were measured by radioimmunoassay and the values are reported as mean ± SEM. These data suggest that endogenous neuropeptide Y in the medial preoptic area has an inhibitory action on prolactin secretion through Y₁ receptors.

Palabras llave : neuropeptide Y; medial preoptic area; neuropeptide Y-Y₁ receptor; prolactin; mRNA for neuropeptide; Y-Y₁ receptor; luteinizing hormone; follicle-stimulating hormone.