Respiratory adjustments of the unanaesthetized chicken, Gallus domesticus, to elevated metabolism elicited by 2,4-dinitrophenol or cold exposure.
The effects of pharmacologically elevated metabolism on ventilation, gaseous exchange and blood gases were studied in spontaneously breathing unanaesthetized decerebrate chickens using 2,4-dinitrophenol (DNP) injected intravenously in successive single doses of 2.5-5.0 mg/kg. These responses were compared with the cardiorespiratory adjustments to elevated metabolism evoked by shivering in conscious birds. Oxygen consumption increased with cumulative amounts of DNP, reaching 275 +/- 30% of control values at the maximum tolerated dose of 10-15 mg/kg. Increases in ventilation matched the changes in oxygen consumption via increases in both breathing frequency and tidal volume. Arterial blood gases and pH remained unchanged. Exposure to cold (Ta = 2 +/- 2 degrees C) caused oxygen consumption to increase to 185 +/- 21% of control values. Respiratory and cardiovascular adjustments were similar to those evoked by DNP and were comparable to those produced by low intensity treadmill exercise (cf. Gleeson and Brackenbury, 1984).
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D019297:2,4-Dinitrophenol; D000064:Acclimatization; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000032:analysis; D002645:Chickens / Q000378:metabolism*; D003080:Cold Temperature; D004140:Dinitrophenols / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007700:Kinetics; D010100:Oxygen / Q000032:analysis; D010101:Oxygen Consumption / Q000187:drug effects; D010313:Partial Pressure; D012119:Respiration
D004140:Dinitrophenols; D002245:Carbon Dioxide; D019297:2,4-Dinitrophenol; D010100:Oxygen