Progesterone Protects against Hypoxic Ventilatory Depression in Male Rats
It has been suggested that a high level of progesterone facilitates the increase in ventilation during hypoxia in animals as well as in humans (1,2). Recently, Bayliss et al. reported that progesterone stimulates respiration through a central mechanism in anesthetized cat (3). However, there have been few studies concerning the mechanisms of action of progesterone on the ventilatory response to hypoxia. In this study, we sought to determine the effects of progesterone on hypoxic ventilatory depression as well as stimulation. We hypothesized that administration of progesterone, chlormadinone acetate (CMA), may protect the deterioration of respiratory function during hypoxia. To elucidate the possible site(s) of drug action, we also compared the ventilatory response to hypoxia before and after bilateral sectioning of the carotid sinus nerves, with or without administration of progesterone in the rat.
KeywordsDepression Attenuation Respiration Progesterone Halothane
Unable to display preview. Download preview PDF.
- 2.Kimura H, Tojima H, Kobayashi T, Kuriyama T, Fukuda Y (1987). Attenuation of hypoxic ventilatory depression and augmentation of CO2 chemosensitivity by a synthetic progesterone. Am Rev Respir Dis 135: A368.Google Scholar
- 5.Lahiri S, Gelfand R (1981). Mechanism of acute ventilatory responses. In: Horbein F (Ed). Regulation of Breathing, Part II. New York: Marcel Dekker, pp. 773–843.Google Scholar