The Tissue Catecholamine Concentration of the Rabbit in Experimental Cardiac Failure

Abstract

The determination of urine and tissue catecholamine levels were undertaken in rabbit with or without cardiac failure produced by aortic obstruction. The tissue catecholamine have tended to be lowered in cardiac failure, especially in the heart, while urinary catecholamine levels showed elevation. Uptake of the exogenous noradrenaline by the heart was lowered in cardiac failure than that of the normal subject. It was found that with nialamide, propranolol, or bethanidine, catecholamine concentration of heart could have increased in normal health, but in cardiac failure, such increase could be suppressed. It has been known that a condition of catecholamine depletion of the tissues by reserpine appears to be associated with aggravation of cardiac failure. The failing heart seems to yield acceleration of the sympathoadrenal activity, which results in depletion of tissue catecholamine perhaps due to the increased release of stored catecholamine and deficient retention by enhanced turnover rate, or lowered uptake in the tissues. It is concluded that the tissue catecholamine plays a compensatory role in cardiac failure.