Acrosome reaction changes the pattern of cyclic nucleotide phosphodiesterases in human sperm.
Three categories of cyclic nucleotide phosphodiesterases (cNPDE) are distinguished at present: type 1 with high affinity to cyclic GMP; type 2 with low affinity to cyclic AMP and to cyclic GMP; and type 3 with high affinity to cyclic AMP. For the evaluation of normal values in human spermatozoa 50 semen samples with normal classical semen parameters were investigated. The activities (means +/- SD) of the cNPDE types (10(-11) mol/10 min x 10(8) spermatozoa) of washed human spermatozoa amounted to 47 +/- 22 (type 1), 3350 +/- 1537 (type 2), and 70 +/- 38 (type 3). A significant inhibition of type 3 by cyclic GMP could not be detected. One milligram protein of the spermatozoa hydrolyzed about 20-fold the amount of cyclic nucleotides compared with 1 mg protein of the seminal plasma. Furthermore, the cNPDE of the spermatozoa and of the seminal plasma differed in the influence of type 3 by cyclic GMP and in the pattern of activities. The acrosome reaction (AR) induced by the cold shock method led to an activation of type 2 and 3 unlike the initiation of the AR by the digitonin method. The latter did not cause significant differences of the cNPDE activities before and after the AR.
Glander
H J
HJ
Department of Dermatology/Andrology, University of Leipzig, Germany.
Dettmer
D
D
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism*; D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism*; D000177:Acrosome / Q000201:enzymology*; D004789:Enzyme Activation / Q000502:physiology; D006801:Humans; D007248:Infertility, Male / Q000201:enzymology; D008297:Male; D012661:Semen / Q000201:enzymology; D013094:Spermatozoa / Q000201:enzymology* / Q000648:ultrastructure
D015105:3',5'-Cyclic-AMP Phosphodiesterases; D015106:3',5'-Cyclic-GMP Phosphodiesterases