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Sex differences in mouse heart rate and body temperature and in their regulation by adenosine A 1 receptors
Author(s) -
Yang J.N.,
Tiselius C.,
Daré E.,
Johansson B.,
Valen G.,
Fredholm B. B.
Publication year - 2007
Publication title -
acta physiologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.591
H-Index - 116
eISSN - 1748-1716
pISSN - 1748-1708
DOI - 10.1111/j.1365-201x.2007.01690.x
Subject(s) - caffeine , medicine , heart rate , adenosine , endocrinology , adenosine receptor , agonist , adenosine receptor antagonist , adenosine a1 receptor , receptor , antagonist , chemistry , biology , blood pressure
Aim: To examine cardiac function, body temperature and locomotor behaviour in the awake adenosine A 1 receptor knock out mouse of both sexes. Methods: Male and female A 1 R (+/+) and (−/−) mice, instrumented with telemetric devices, were recorded during basal conditions and after drug administration. Results: Female mice had higher heart rate, body temperature and locomotion, both during daytime and during the night. Awake A 1 R (−/−) mice had a slightly elevated heart rate, and this was more clear‐cut in males. Heart rate was also higher in Langendorff‐perfused denervated A 1 R (−/−) hearts. Body temperature was higher in A 1 R (−/−) males and females; locomotor activity was higher in A 1 R (−/−) females, but not in males. The adenosine receptor agonist R‐PIA (0.2 mg kg −1 ) decreased heart rate and body temperature, but less in A 1 R (−/−) animals than in A 1 R (+/+) mice ( P < 0.001 in both parameters). The unselective adenosine receptor antagonist caffeine had a minor stimulatory effect on heart rate in lower doses, but depressed it at a dose of 75 mg kg −1 . Body temperature was increased after a low dose (7.5 mg kg −1 ) of caffeine in both sexes and genotypes, and markedly reduced after a high dose (75 mg kg −1 ) of caffeine. An intermediary dose of caffeine 30 mg kg −1 increased or decreased body temperature depending on genotype and sex. Locomotor responses to caffeine were variable depending both on genotype and sex. Conclusion: Thus, the adenosine A 1 receptor is involved in the regulation of heart rate, body temperature and locomotor activity, but the magnitude of the involvement is different in males and females.