E. Schlenker, Gender-specific effects of CNQX administered into the arcuate nucleus on ventilatory patterns in rats, RESP PHYSL, 116(2-3), 1999, pp. 133-143
This study evaluated the effect of microinjection of the non-N-methyl-D-asp
artate (NMDA) receptor antagonist, cyano, 3-dihydro-7-nitrogluinoxaline-2,
3-dione (CNQX), into the arcuate nucleus of the hypothalamus on ventilation
in male and female rats. Conscious rats received saline or 50, 100, or 200
pmol concentrations of CNQX on separate days. Significant interactions bet
ween dose and gender were observed on frequency, inspiratory (Tr) and expir
atory (TE) time, and tidal volume. CNQX depressed frequency, but increased
tidal volume in female rats. Effects of CNQX in males on these ventilatory
parameters were considerably less. In CNQX-treated females the decrease in
frequency of breathing was primarily due to an increase in Tr. Exposure of
CNQX-treated female rats to hypercapnia, but not to hypoxia transiently dec
reased TI. No effect of CNQX was noted on oxygen consumption or body temper
ature. Thus, non-NMDA receptors in the arcuate nucleus are involved in modu
lating ventilatory patterns in a gender-specific manner independent of its
effects on oxygen consumption or body temperature. (C) 1999 Elsevier Scienc
e B.V. All rights reserved.