Ventilatory response to severe acute hypoxia in guinea-pigs and rats with high hemoglobin-oxygen affinity induced by cyanate.
Baseline ventilation, hemoglobin concentration (Hb) and P50 were significantly lower in guinea-pigs than in rats. Chronic sodium cyanate (NaOCN) administration did not significantly increase hemoglobin concentration in either guinea-pigs or rats. It decreased the P50 significantly less in guinea-pigs than in rats. The high Hb-O2 affinity experimentally induced did not modify the hypoxic ventilatory response (HVR) of guinea-pigs and rats. At the same level of acute hypoxia, HVR was significantly lower in NaOCN guinea-pigs than in NaOCN rats. Guinea-pigs, genotypically adapted animals to high altitude, displayed relatively minor ventilatory and Hb-O2 affinity changes to NaOCN, and a relatively minor HVR to acute hypoxia. They probably use tissue and biochemical adaptive mechanisms, in addition to their limited extracellular responses to successfully tolerate ambient hypoxia.
Rivera
M
M
Departamento de Ciencias Fisiológicas, Universidad Peruana Cayetano Heredia, Lima.
León-Velarde
F
F
Huicho
L
L
Monge
C
C
D000208:Acute Disease; D000818:Animals; D003485:Cyanates / Q000494:pharmacology*; D006168:Guinea Pigs; D006454:Hemoglobins / Q000187:drug effects / Q000378:metabolism*; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats; D015656:Respiratory Mechanics / Q000187:drug effects*; D013045:Species Specificity
D003485:Cyanates; D006454:Hemoglobins