Anaero bic heat production of bull spermatozoa.

A micro-calorimeter, suitable for detecting rates of heat production of the order of 1 mcal/h in about 2*3 ml. fluid, is described. Measurements have been made with it of the anaerobic heat production of bull spermatozoa in semen. The result, for the first hour, 220+ 15 mcal/109 live spermatozoa/h at 37° C, is consistent with the hypothesis that, in the first hour of incubation, the heat produced is derived from the enthalpy change associated with the breakdown of fructose to lactic acid. In the second hour of incubation the heat produced by the spermatozoa, 111 + 18 mcal/109 live spermatozoa/h at 37° C, was sometimes greater than that associated with fructolysis. Measurements were also made of the heat production of spermatozoa killed or inactivated by various methods, of seminal plasma, and of the heat of partial neutralization of seminal plasma by lactic acid.