Abstract: | The content and metabolism of cyclic nucleotides in the aorta as well as contractility were studied in rats given different doses of indometacin. High doses of the drug (5 mg/kg) favored an abrupt decrease in cAMP and cGMP levels in the aorta and did not essentially affect vascular response to electric stimulation. Low doses of indometacin (2 mg/kg), particularly when coupled with salt load, resulted in the decreased cAMP/cGMP ratio and in the potentiation of vasoconstrictor responses. It has been demonstrated that the reduced proportion of cAMP in cyclic nucleotide metabolism is related to the activation effect of indometacin on cAMP-phosphodiesterase activity. The role of the prostaglandin-cyclic nucleotide system in the vascular tone control is discussed. |