[Effect prolonged GABAergic activation on the pubertal development of female rats].
We evaluated, in immature female rats, the effect of the GABAergic system on the reproductive axis and on pubertal development. Initially, using a prolonged treatment with aminooxyacetic acid (AOAA), increasing hypothalamic GABA (p < 0.002), and decreasing GnRH and glutamate content (p < 0.05 and < 0.02). Treated rats showed diminished serum LH (p < 0.05) and estradiol (p < 0.005) levels. Vaginal opening occurred at 30.8 +/- 0.6 days in controls, and at 36.7 +/- 0.98 days in AOAA-treated rats. Acute treatment with AOAA resulted in a decreased GnRH and glutamate output, and in an increased taurine release from superfused hypothalamic fragments. This effect was mimicked by the GABA-A and GABA-B agonists. The activation of the GABAergic system during postnatal days 23-29 significantly restrains the hypothalamo-pituitary-ovaric axis and delays the onset of puberty. The existence of a physiological cross-talk between excitatory and inhibitory amino acid neurotransmitters regulating GnRH release during the onset of puberty is postulated.
Feleder
C
C
Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Argentina. feleder@ciudad.com.ar
Guinzburg
M
M
Wuttke
W
W
Moguilevsky
J A
JA
Arias
P
P
D000625:Aminooxyacetic Acid / Q000008:administration & dosage*; D000818:Animals; D000831:Animals, Newborn; D016022:Case-Control Studies; D004958:Estradiol / Q000097:blood; D005260:Female; D018682:GABA Agents / Q000008:administration & dosage*; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013654:Taurine / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000187:drug effects* / Q000378:metabolism
D018682:GABA Agents; D018377:Neurotransmitter Agents; D000625:Aminooxyacetic Acid; D013654:Taurine; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D005680:gamma-Aminobutyric Acid