Adenosine triphosphate in human semen: a study on conditions for a bioluminescence assay

A comparison of different procedures for adenosinetriphosphate (ATP) determination in whole ejaculates showed that it is advantageous to treat the specimens with trichloroacetic acid (TCA before quantification of ATP by bioluminescence). Semen samples from different men were found to cause varying degrees of inhibition of the luciferin-luciferase reaction. Hence, internal ATP standard had to be added to each sample to allow calculation of endogenous ATP. Mean recovery of ATP was 98.5%. The intrassay and interassay coefficients of variation were 3.0% and 3.9%, respectively. A correlation between the number of progressively motile spermatozoa and the ATP concentration was found (r = 0.89, P = 0.0005, n = 22). The mean level of ATP was 0.49 nmol/living sperm X 10(6) in semen with normal sperm motility and sperm density obtained from 22 men attending our fertility clinic. Seminal ATP was detected only in the spermatozoa.