Role of nitric oxide in hypoxic hypometabolism in rats

Henry Gautier; Cristina Murariu

$Abstract Because it has been recently suggested that nitric oxide (NO) may mediate the effects of hypoxia on body temperature and ventilation, the present study was designed to assess more completely the effects of a neuronal NO synthase inhibitor (7-nitroindazole, 25 mg/kg ip), at ambient temperature of 26 and 15°C, on the ventilatory (V˙), metabolic (O 2 consumption), and thermal changes (colonic and tail temperatures) induced by ambient hypoxia (fractional inspired O 2 of 11%) or CO hypoxia (fractional inspired CO of 0.07%) in intact, unanesthetized adult rats. At both ambient temperatures, 7-nitroindazole decreased oxygen consumption, colonic temperature, andV˙ in normoxia. The drug reduced ambient or CO hypoxia-induced hypometabolism and ventilatory response, but the hypothermia persisted. It is concluded that NO arising from neural NO synthase plays an important role in the control of metabolism andV˙ in normoxia. As well, it mediates, in part, the hypometabolic and the ventilatory response to hypoxia. The results are consistent with the notion that central nervous system hypoxia resets the thermoregulatory set point by decreasing brain NO. thermoregulation control of breathing carbon monoxide cold Footnotes Address for reprint requests and other correspondence: H. Gautier, Atelier de Physiologie Respiratoire, Faculté de Médecine St-Antoine, 27, rue Chaligny, 75012 Paris, France. The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “ advertisement ” in accordance with 18 U.S.C. §1734 solely to indicate this fact. Copyright © 1999 the American Physiological Society$

Role of nitric oxide in hypoxic hypometabolism in rats

Gautier, Henry; Murariu, Cristina

Follow Journal of Applied Physiology , Volume 87 (1): 104 The American Physiological Society – Jul 1, 1999