[A study of the regulatory role of GABA on the LHRH release in the median eminence of rats].
The present study was undertaken to observe the effect of GABA and NA on LHRH neuronal terminals in the median eminence (ME). The results showed that GABA (10(-6) mol/L) significantly increased LHRH and NA release from ME, i.e., respectively from 27.3 +/- 2.5 pg/100 microliters to 150.4 +/- 27.9 pg/100 microliters and from 50.9 +/- 4.2 pg/100 microliters to 105.5 +/- 19.1 pg/100 microliters (both P less than 0.01 vs control group). These effects of GABA could be blocked by bicuculline. When bicuculline and GABA (10(-6) mol/L) were added into the ME, the secretion of LHRH decreased to 18.2 +/- 1.9 pg/100 microliters and that of NA to 43.9 +/- 3.4 pg/100 microliters. The effect of GABA on LHRH release may be mediated by NA. When endogenous NA was depleted by reserpine, GABA increased LHRH secretion only by 26.5% instead of 451.9% as in the normal animal.
Luo
L G
LG
Shanghai Institute of Planned Parenthood Research.
Zhao
B G
BG
Zhao
W
W
Zhu
X Z
XZ
D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D046508:Culture Techniques; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D008297:Male; D008473:Median Eminence / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology / Q000502:physiology*
D011963:Receptors, GABA-A; D007987:Gonadotropin-Releasing Hormone; D005680:gamma-Aminobutyric Acid; D009638:Norepinephrine; D001640:Bicuculline