Levels of Adenin-nucleotides In the Myocardium of Rats in Experimental Hyper and Hypothyroidism

Abstract

The adenin-nucleotide concentrations (ATP, ADP, AMP) and orthophosphate (Pi) were studied in the ventricular myocardium of 4 groups of 10 male Wistar rats in the following conditions: 1) Controls; 2) and 3) were injected v.i.p. with thyroid hormone (T4) 0.25 and 0.50 mg/Kg/day for 16 days, respectively; 4) thyroidectomyzed after 16 days. An ATP decrease and a Pi increase, both significant, were observed in the ventricular myocardium of rats treated with 0.50 mg T4; while the group treated with 0.25 mg T4 did not show any significant parameter changes. The thyroidectomyzed group, however, experienced an ATP increase and a significant decrease in the concentrations of ADP, AMP and Pi with respect to the control group.