Studies of the Fixation of Carbon Dioxide by Washed Ram Spermatozoa

Abstract

Fixation of carbon dioxide by ram spermatozoa was studied by incubating washed cells with NaH14C03? More fixation of carbon dioxide occurred as the substrate concentration was increased, and was very low in the absence of added substrate. Less incorporation occurred with acetate than with pyruvate or lactate. A marked increase in fixation was seen when ketoglutarate or malate replaced portion of the lactate in the medium, but not when other tricarboxylic acid cycle intermediates were substituted. Fixation of carbon dioxide was higher when ketoglutarate plus malate rather than when either substrate alone partially replaced lactate.