Summary: Comp. Biochem. Physiol. Vol. 118A, No. 1, pp. 131139, 1997 ISSN 0300-9629/97/$17.00
Copyright © 1997 Elsevier Science Inc. PII S0300-9629(96)00402-1
Cholinergic and Adrenergic Tones
in the Control of Heart Rate in Teleosts.
How Should They be Calculated?
and Michael Axelsson2
Unitat de Fisiologia Animal, Facultat de Cie`ncies, Universitat Auto`noma de Barcelona,
E-08193 Bellaterra, Spain; and 2
Department of Zoophysiology, Go¨teborg University, Medicinaregatan 18,
S-413 90 Go¨teborg, Sweden
ABSTRACT. Cholinergic and adrenergic tones were calculated for three different teleost fish species: Gadus
morhua, Labrus bergylta, and Sparus aurata using atropine as a muscarinic receptor antagonist and either sotalol
or propranolol as -adrenoceptor antagonists. Depending on the order of administration of atropine and the
two -adrenoceptor antagonists, it was observed that propranolol but not sotalol enhanced cholinergic tone.
Thus, if propranolol is used to determine autonomic cardiac influences, it has to be injected after atropine and
not before. Differences in intrinsic heart rate were observed between treatments in two of the three species