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Drinking and antidiuresis elicited by isoprenaline in the dog
Author(s) -
Fitzsimons J. T.,
SzczepańskaSadowska Ewa
Publication year - 1974
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1974.sp010567
Subject(s) - isoprenaline , propranolol , phentolamine , preload , hexamethonium , medicine , endocrinology , metaraminol , heart rate , thirst , blood pressure , hemodynamics , chemistry , anesthesia , atropine , stimulation
1. Isoprenaline hydrochloride injected subcutaneously or infused intravenously caused drinking and simultaneous antidiuresis in the dog. The minimal effective dose was between 20 and 50 μg per dog. 2. Isoprenaline‐induced drinking was prevented by the β‐adrenergic antagonist propranolol and enhanced by the α‐antagonist phentolamine. 3. Ganglionic blockade with pentolinium or with hexamethonium did not interfere with the response. 4. A delay of 1 hr after injection of 100 μg isoprenaline, before drinking was permitted, did not significantly reduce the amount of water subsequently drunk. A preload of water approximately equal to the volume of water normally drunk caused a greater reduction in water intake in some dogs. 5. Isoprenaline caused an increase in heart rate and pulse pressure which lasted for between 1 and 3 hr according to dose. Central venous pressure fell, but mean arterial pressure was little altered. Haemodynamic changes preceded drinking by about 5 min. 6. Infusion of isoprenaline caused drinking in the bilaterally nephrectomized dog. 7. We conclude that isoprenaline is a potent stimulus to drinking in the dog and that the effect is not exclusively mediated by the renin‐angiotensin system.