Effect of temperature on beta receptor responsiveness in guinea pig pulmonary tissues.
Cumulative concentration-effect relationships of isoproterenol (isoprenaline) on guinea pig tracheal spirals and lung parenchymal strips were determined in organ baths kept at 37 degrees C or at 18 degrees C. The IC50's for isoproterenol at 18 degrees C were significantly (p less than .01) higher than those for isoproterenol at 37 degrees C in both the tissues; although the parenchymal response was affected more than that of the trachea by cooling. pA2 values for propranolol were determined on both tracheal spirals and parenchymal strips at 37 degrees C and 18 degrees C. The pA2 values were decreased in both the tissues by cooling. The decrease was more prominent in the parenchyma than in the trachea, a finding consistent with the concentration-effect relationships studies mentioned above.
D000403:Airway Resistance / Q000187:drug effects; D000818:Animals; D003080:Cold Temperature; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008168:Lung / Q000502:physiology*; D008297:Male; D011433:Propranolol / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology*; D014132:Trachea / Q000187:drug effects
D011943:Receptors, Adrenergic, beta; D011433:Propranolol; D007545:Isoproterenol