Effect of beta-adrenoceptive blocking agents on the response to bronchoconstrictor drugs in the guinea-pig air overflow preparation. Appendix describing a new modification of the air overflow method.
1. Propranolol augmented the bronchoconstrictor response to methacholine or histamine, recorded by air overflow in the anaesthetized, vagotomized guinea-pig.2. After adrenalectomy, propranolol was still active, though less so than before.3. In the pithed guinea-pig, there was no augmentation of the effect of bronchoconstrictors on air overflow. The action of propranolol could thus be due to the beta-adrenoceptor blockade of compensatory sympathetic bronchodilator activity, as concluded by McCulloch, Proctor & Rand (1967).4. Electrical stimulation of the thoracic region of the spinal cord of the pithed guinea-pig reduced the effect of bronchoconstrictors on air overflow. This reduction could be blocked by propranolol; practolol was much less effective.
D000083:Acetanilides / Q000494:pharmacology; D000311:Adrenal Glands / Q000502:physiology; D000315:Adrenalectomy; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D002818:Cordotomy; D004357:Drug Synergism; D004558:Electric Stimulation; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology*; D008688:Methacholine Compounds / Q000494:pharmacology*; D008722:Methods; D011433:Propranolol / Q000494:pharmacology; D012137:Respiratory System / Q000187:drug effects*; D013116:Spinal Cord / Q000502:physiology; D013147:Spirometry / Q000295:instrumentation; D013565:Sympatholytics / Q000494:pharmacology*; D014628:Vagotomy
D000083:Acetanilides; D000319:Adrenergic beta-Antagonists; D008688:Methacholine Compounds; D013565:Sympatholytics; D006632:Histamine; D011433:Propranolol