K. Nonogaki et al., ACTIVATION OF GABA-A RECEPTOR IN THE BRAIN SUPPRESSES NEOSTIGMINE OR HISTAMINE-INDUCED CENTRAL NERVOUS SYSTEM-MEDIATED HYPERGLYCEMIA, Life sciences, 53(9), 1993, pp. 159-163
We investigated the effect of GABA receptor agonists on the central ne
rvous system (CNS)-mediated hyperglycemia induced by neostigmine or hi
stamine in anesthetized fed rats. The injection of muscimol, GABA(A) r
eceptor agonist (1, 2.5 nmol) into the third cerebral ventricle suppre
ssed the hyperglycemia induced by intraventricular injection of neosti
gmine (1x10(-8) mol) or histamine (5x10(-7) mol) . Baclofen, GABA(B) r
eceptor agonist (1, 2.5 nmol) , however, did not suppress these hyperg
lycemia. Neither muscimol nor baclofen (2.5 nmol) affected plasma gluc
ose levels. These findings suggest that activation of GABA(A) receptor
in the CNS suppresses the hyperglycemia induced by the stimulation of
cholinoceptive neuron or histaminergic neuron, but activation of GABA
(B) receptor does not affect them.