Cardiovascular responses to adrenergic agents in different acclimation states in the rock pigeon (Columba livia).
The effect of propranolol on heart rate (fH) was measured in season-acclimatized pigeons. Propranolol treatment decreased fH in winter-acclimatized pigeons, accelerated fH in summer-acclimatized pigeons, but had no effect on fH in spring-acclimatized pigeons. The effect of propranolol in summer-acclimatized pigeons is opposite to that observed in mammals. Interestingly, isoproterenol produced a propranolol-like cardioacceleration in heat-acclimated pigeons. We suggest that propranolol affects fH in summer-acclimatized pigeons via two opposing routes-a direct and a peripheral indirect route. We also suggest that the cardiovascular effects of propranolol are involved in the capacity of the pigeon to evaporate water from its skin.
Ophir
E
E
Department of Cell and Animal Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Israel. eshel@vms.huji.ac.il
Arieli
Y
Y
Raber
P
P
Marder
J
J
D000064:Acclimatization / Q000502:physiology*; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D010856:Columbidae / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D007267:Injections; D007545:Isoproterenol / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology*; D012621:Seasons
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011433:Propranolol; D007545:Isoproterenol