Activation of AMPA receptors inhibits prolactin and estradiol secretion and delays the onset of puberty in female rats

Previous experiments have evidenced the neuroendocrine role of AMPA recepto rs. Present studies were carried out to obtain information on the role of t hese receptors in the control of the onset of puberty. To this end, female rats were i.c.v. injected with vehicle or AMPA (agonist of AMPA receptors: 0.1 or 0.5 nmol;day) between 26 and 30 days (Experiment 1), or 30 and 34 da ys (Experiment 2) of age. Serum concentrations of PRL. LH and estradiol wer e measured before drug administration, 10 min after the last injection, at vaginal opening (VO) and at first estrus (FE) presentation. In both experim ents, AMPA administration inhibited PRL and estradiol secretion without aff ecting LH release. When AMPA was administered between 26 and 30 days a sign ificant delay in the day of vaginal opening was observed. These results con firmed the inhibitory effect of AMPA on PRL secretion and suggests a role o f AMPA receptors in the control of puberty onset. (C) 2001 Elsevier Science Ltd. All rights reserved.