Significance of adenosinetriphosphate in human sperm as clinical parameter

Adenosine triphosphate (ATP) in human spermatozoa

The seminal adenosine triphosphate (ATP) content was determined by bioluminescence after treatment with trichloroacetic acid (TCA) in 81 semen samples 1.5 h after ejaculation obtained from men attending our fertility clinic, and selected to contain either 20% or less spermatozoa with good progressive motility (n = 22), or 60% or more spermatozoa with good progressive motility (n = 59) (Study I), and in 18 semen samples from fertile men 30 min and 3.5 h after ejaculation (Study II). The latter samples were divided into 2 equally large groups according to sperm motility. In Study I the mean sperm ATP concentration was significantly higher in the semen samples with bad motility (0.63 nmol per living spermatozoa x 10(-6)) than in semen samples with good motility (0.39 nmol per living spermatozoa x 10(-6); P less than 0.01). In Study II the ATP concentration per living spermatozoa was also lower in the group with the best motility in comparison with the spermatozoa with lower motility (P less than 0.01), both 30 min and 3.5 h after ejaculation. During the 3-5 h incubation the sperm ATP concentration decreased by 21% (P less than 0.01) in the former group of samples but remained unchanged in the latter group. The results indicate that, in semen samples with highly motile spermatozoa, the consumption of ATP is higher than in semen samples with impaired sperm motility. It is therefore essential that the time between ejaculation and ATP measurement is as short as possible to obtain comparable results. Repeated ATP measurements in combination with an analysis of the number of living spermatozoa, may provide further information on the fertilizing capacity of spermatozoa.

Absence of correlation between the levels of ATP and other seminal compounds in semen and the results of human in-vitro fertilization

As part of an in-vitro fertilization programme (IVF), semen levels of adenosine triphosphate, fructose, citrate, zinc, free L-carnitine and glycerophosphocholine were measured in 178 men. None of these substances appeared to have any predictive value with regard to the fertilizing potential of the semen during IVF.

ATP content in human semen and sperm quality

Five semen characteristics (count, motility, normal forms, bovine cervical mucus penetration, and ATP) were evaluated in patients attending the infertility clinic. Multiple regression analysis indicated that the only characteristic independently affecting ATP concentration was sperm count, whereas motility and percent normal forms had no additional contribution to ATP level. Penetration into bovine cervical mucus did not depend on ATP levels. Comparison of semen characteristics in the same group between patients who have impregnated their wives and those who have not indicated that with respect to count, motility, morphology, and ATP the only sperm characteristic independently predicting fertility was motility. ATP measurements have limited value in the evaluation of semen quality.

On the use of adenosine triphosphate for estimation of motility and energy status in human spermatozoa

Following the development of a reliable technique for analysis of total ATP in semen, the ATP concentration of untreated human ejaculates was compared with progressive sperm motility during 3 continuous days following ejaculation. As correlation was poor between these variables, spermatozoa were separated by self-migration on Percoll gradients and washed free of Percoll solution. ATP concentration and sperm motility was then assessed. Aliquots of separated sperms were transferred to separate tubes, and increasing concentrations of sera were added prior to incubation at 37 degrees C for 4 days. Under these conditions a good correlation between specific progressive motility and specific ATP content was found (r = 0.88). A high concentration of human blood serum (10% v/v) was found to be necessary for maintainance of motility, but neither the addition of bovine serum albumin nor an increase in the glucose concentration had any effect on sperm motility or on the ATP concentration. Addition of different fractions of human blood serum indicated that the components mainly responsible for maintaining sperm motility are greater than 10,000 daltons. Our findings strongly indicate that ATP assessment can be used to estimate the energetic condition of a human sperm population after its separation from seminal plasma. It is suggested that this in vitro system can be used to define optimal conditions for sperm function.