TY - JOUR
T1 - AN ANALYSIS OF THE RESPIRATORY STIMULANT EFFECT OF PHYSOSTIGMINE AND NEOSTIGMINE DM THE CONSCIOUS RABBIT
AU - Weinstock, M.
AU - Roll, D.
AU - Zilberman, Y.
PY - 1981/4
Y1 - 1981/4
N2 - 1. The effects of physostigmine and neostigmine, given by continuous intravenous infusion, were studied on respiration in conscious rabbits. 2. Physostigmine (5 μg/kg per min) significantly increased respiration rate, decreased arterial PaCO2 from 25.4 ± 0.9 to 19.8 ± 1.5 mmHg, increased PaCO2 from 100.3 ± 1.9 to 108 ± 3.0 and pH from 7.42 ± 0.01 to 7.46 ± 0.01 within 30 min of its infusion. 3. Neostigmine (2.5 μg/kg per min) also decreased PaCO2 and increased PaO2 significantly, but caused a concomitant lactic acidosis, which was associated with the increased muscular activity and fasciculations. 4. The respiratory stimulant effect of neostigmine, but not that of physostigmine, was abolished by hexamethonium 2 × (1.5 mg/kg). Atropine methyl nitrate (1 mg/kg) failed to influence the respiratory stimulant effect of physostigmine, but hyoscine (10 mg/kg) blocked it completely. 5. It is suggested that augmentation of respiratory activity by neostigmine is mediated via peripheral nicotinic receptors in the carotid and aortic bodies. This may occur either through the accumulation of acetylcholine or of H+ ions from raised blood lactic acid. 6. It is further suggested that physostigmine stimulates respiration by raising the concentration of acetylcholine in the central nervous system which, in turn, activates muscarinic receptors.
AB - 1. The effects of physostigmine and neostigmine, given by continuous intravenous infusion, were studied on respiration in conscious rabbits. 2. Physostigmine (5 μg/kg per min) significantly increased respiration rate, decreased arterial PaCO2 from 25.4 ± 0.9 to 19.8 ± 1.5 mmHg, increased PaCO2 from 100.3 ± 1.9 to 108 ± 3.0 and pH from 7.42 ± 0.01 to 7.46 ± 0.01 within 30 min of its infusion. 3. Neostigmine (2.5 μg/kg per min) also decreased PaCO2 and increased PaO2 significantly, but caused a concomitant lactic acidosis, which was associated with the increased muscular activity and fasciculations. 4. The respiratory stimulant effect of neostigmine, but not that of physostigmine, was abolished by hexamethonium 2 × (1.5 mg/kg). Atropine methyl nitrate (1 mg/kg) failed to influence the respiratory stimulant effect of physostigmine, but hyoscine (10 mg/kg) blocked it completely. 5. It is suggested that augmentation of respiratory activity by neostigmine is mediated via peripheral nicotinic receptors in the carotid and aortic bodies. This may occur either through the accumulation of acetylcholine or of H+ ions from raised blood lactic acid. 6. It is further suggested that physostigmine stimulates respiration by raising the concentration of acetylcholine in the central nervous system which, in turn, activates muscarinic receptors.
KW - conscious rabbits
KW - muscarinic receptors in CNS
KW - neostigmine
KW - nicotinic receptors in carotid body
KW - physostigmine
KW - respiratory stimulation
UR - http://www.scopus.com/inward/record.url?scp=0019422893&partnerID=8YFLogxK
U2 - 10.1111/j.1440-1681.1981.tb00146.x
DO - 10.1111/j.1440-1681.1981.tb00146.x
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C2 - 6788414
AN - SCOPUS:0019422893
SN - 0305-1870
VL - 8
SP - 151
EP - 158
JO - Clinical and Experimental Pharmacology and Physiology
JF - Clinical and Experimental Pharmacology and Physiology
IS - 2
ER -