-transparent.png){kind=logo}
1. The pharmacokinetics and the dromotropic action (increased PQ interval) of intravenously administered ajmaline (2 mg kg-1) were studied in hyperthyroid rats with sinus tachycardia. The hyperthyroidism was induced by intraperitoneal injection of 3,5,3'-triiodo-L-thyronine (0.5 mg kg-1) for 4 days. 2. The change in the ajmaline concentration in whole blood could be described by a biexponential equation. The steady state distribution volume of ajmaline decreased from 4.81 l kg-1 in control rats to 3.80 l kg-1 in hyperthyroid rats and the total body blood clearance was slightly higher in hyperthyroid rats than in control rats. 3. Ajmaline exhibited a saturable binding to rat plasma proteins, and one kind of binding site was found in the observed range of concentrations. The binding capacity was 2 fold higher in hyperthyroid rats than in control rats. 4. On the basis of the plasma unbound concentration, ajmaline exhibited an increased negative dromotropic activity in hyperthyroid rats compared with control rats. 5. A positive correlation was found between the pacing rate and the dromotropic action of ajmaline on atrioventricular conduction in isolated perfused hearts. There was no significant difference in the rate-dependence of the effect of ajmaline on the heart between control and hyperthyroid rats. 6. Our findings suggest that the increased dromotropic activity of ajmaline is mainly due to the increased heart rate in hyperthyroid rats.
Y Hashimoto, and
M Yasuhara, and
A Kamiya, and
K Okumura, and
R Hori
January 1967,
Therapie,
Y Hashimoto, and
M Yasuhara, and
A Kamiya, and
K Okumura, and
R Hori
December 1976,
Archives internationales de pharmacodynamie et de therapie,
Y Hashimoto, and
M Yasuhara, and
A Kamiya, and
K Okumura, and
R Hori
January 1987,
European journal of drug metabolism and pharmacokinetics,
Y Hashimoto, and
M Yasuhara, and
A Kamiya, and
K Okumura, and
R Hori
July 1977,
Archives des maladies du coeur et des vaisseaux,
Y Hashimoto, and
M Yasuhara, and
A Kamiya, and
K Okumura, and
R Hori
November 1993,
Clinical pharmacokinetics,
Y Hashimoto, and
M Yasuhara, and
A Kamiya, and
K Okumura, and
R Hori
July 2014,
Journal of ovarian research,
Y Hashimoto, and
M Yasuhara, and
A Kamiya, and
K Okumura, and
R Hori
January 1993,
Biological & pharmaceutical bulletin,
Y Hashimoto, and
M Yasuhara, and
A Kamiya, and
K Okumura, and
R Hori
January 1978,
European journal of pharmacology,
Y Hashimoto, and
M Yasuhara, and
A Kamiya, and
K Okumura, and
R Hori
January 1982,
European journal of clinical pharmacology,
Y Hashimoto, and
M Yasuhara, and
A Kamiya, and
K Okumura, and
R Hori
January 1991,
Research in veterinary science,
