EFFECT OF ADRENALIN ON PULMONARY VENTILATION: PROPORTIONALITY WITH DOSE

Publisher Website
Google Scholar
Abstract
Intraven. inj. of adrenalin at rates of 0. 00025 to 0. 01000 mg. per kg per min. for 5 mins. increases minute-vol. of pulmonary ventilation of chloralose-anesthetized cats as follows: The minimal effective rate of inj. is 0. 001 mg. per kg per min.; this is the same threshold as for blood lactic acid increase and for definite, sustained increase in O2 consumption. For the 5-min. inj. period maximum increase in pulmonary ventilation occurs also at threshold rate of adm.; at all higher rates of inj. the increase during inj. itself is progressively less; this is altogether unlike the effect shown either by O2 intake or blood lactic acid and is attributed to the inhibitory effect of the concomitant hypertension which very probably is directly proportional to dosage. Following adm. at rates of 0. 001 and 0. 002 mg. per kg per min. ventilation reaches its maximum increase during inj. and then returns nearly to normal by the end of another 20 mins. (i. e., 1/2 hr. after inj. ). This is very similar to the effect on O2 consumption and tentatively may be regarded as adaptation to metabolic need. Following adm. at rates of 0. 007 and 0. 010 mg. per kg per min. increase in ventilation continues progressively to the end of the subsequent 30-min. interval which was as long as the effect was followed. This is similar to the lactacidemia following these 2 maximal rates of inj. and may be ascribed to it. These interpretations are confirmed by the changes which are observed in composition of the expired air. These results emphasize the complex nature of the respiratory response to adrenalin and by just so much the caution necessary in interpretation of detns. of the respiratory metabolism under the action of this hormone.

This publication has 3 references indexed in Scilit: