Cardiovascular and ventilatory effects of taurine and homotaurine in anaesthetized rats
Paakkari, P.; Paakkari, I.; Karppanen, H.; Halmekoski, J.; Paasonen, M.K.
Medical Biology 60(6): 316-322
1982
ISSN/ISBN: 0302-2137 PMID: 7162225 Document Number: 189687
The cardiovascular and ventilatory effects of i.v. or intracerebroventricular (i.c.v.) injections of the aminosulfonic acids, taurine and homotaurine, were studied in urethane-anesthetized rats. Taurine induced dose-dependent falls in blood pressure, heart rate and ventilatory tidal volume on i.c.v. but not on i.v. administration. Homotaurine induced dose-dependent hypotension and bradycardia when given i.v. and i.c.v. It was more effective when injected i.c.v., and the decrease in ventilatory tidal volume occurred after i.c.v. administration of homotaurine only. Pretreatment of the rats with reserpine attenuated both the hypotensive and bradycardic responses to taurine and homotaurine. Atenolol and atropine both partly inhibited and in combination totally abolished the bradycardiac effects of taurine and homotaurine without changing the hypotensive responses to these compounds. The ventilatory responses were not significantly changed by any of the pretreatments. Evidently the central cardiovascular effects of taurine and homotaurine are mediated both by a decrease in sympathetic tone and an increase in the parasympathetic tone.