Chemoreflexes in rabbits.
Criteria defining chemoreflexes (called responses) in rabbits have been established in relation to right atrial injection of 16 chemicals, and compared with previously-defined chemoreflexes of cats. A vagally mediated 'pulmonary' response elicited at latencies less than 1.6 sec consists only of an increased frequency of breathing due primarily to decrease of expiratory duration. A vagally mediated 'cardiac' response at latencies of 2-3 sec consists of bradycardia, hypotension and a respiratory component of decreased tidal volume. A 'non-vagal excitatory' response probably from the carotid bifurcation region consists predominantly of increased tidal volume, commencing at latencies greater than 2 sec. Stimuli eliciting 'pulmonary' responses were acetic, propionic, butyric, glycolic, lactic, glyoxilic and pyruvic acids, sodium dithionite and phenyl diguanide, and all also elicited the 'non-vagal excitatory' response. Phenyl diguanide additionally elicited the 'cardiac' response. No responses were elicited either by amino-substituted acids (glycine, beta- and L-alanine, 2-amino-butyric acid and GABA) or sodium salts of lactic and acetic acids, except occasionally beta-alanine and GABA elicited a 'non-vagal excitatory' response.
D000143:Acids / Q000494:pharmacology; D000758:Anesthesia; D000818:Animals; D001645:Biguanides / Q000494:pharmacology; D002319:Cardiovascular System / Q000187:drug effects; D002628:Chemoreceptor Cells / Q000502:physiology*; D006880:Hydroxy Acids / Q000494:pharmacology; D007651:Keto Acids / Q000494:pharmacology; D011817:Rabbits; D012018:Reflex / Q000502:physiology*; D012119:Respiration / Q000187:drug effects; D013431:Sulfates / Q000494:pharmacology
D000143:Acids; D001645:Biguanides; D006880:Hydroxy Acids; D007651:Keto Acids; D013431:Sulfates; C004850:sodium dithionate; C008846:phenyl biguanide