A CELLULAR ACTION OF MERCURIAL DIURETICS

¹ Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee

Diuretic and nondiuretic organic mercurials, added in vitro, inhibit the (Na⁺ and K⁺)-activated component of the ATPase system of membrane fragments prepared from rat kidneys. These compounds also reduce the ability of the membrane preparation to stimulate cytoplasmic glycolysis. The (Na⁺ and K⁺)-activated ATPase activity was reduced when membrane fragments were prepared from kidneys of rats pretreated with therapeutic doses of diuretic mercurials. The ability of these membrane preparations to stimulate cytoplasmic glycolysis was also decreased.

Pretreatment with nondiuretic mercurials at equivalent levels did not result in a decreased ability of membrane preparations to stimulate glycolysis. The ATPase activity of the membrane fragments was not significantly inhibited until the mercurial dose was 8 mg Hg/kg.

Thus, a membrane enzyme system that can be correlated with active Na⁺-K⁺ transport has been shown to be inhibited by mercurial diuretics in vitro and in vivo.