Ionized calcium in human seminal plasma.
A low concentration of ionized calcium (Ca++) - 2-4% - was found in human seminal plasma with a calcium sensitive electrode. The mean level of ionized calcium (measured after a standardized air exposition) was 0.17 mM +/- 0.05 (s.d.) (range 0.09-0.29 mM). Dilution of the seminal plasma gave a linear decrease in free calcium concentration. Freezing and thawing or storage of the seminal plasma under anaerobic conditions did not influence the level of ionized calcium. Storage under aerobic conditions gave a temperature dependent decrease in which Ca++ parallelled a spontaneous increase in pH. Spermatozoa in semen samples with an ionized calcium level less than average had a better motility and viability than in semen samples with a higher Ca++ level.
D000328:Adult; D002118:Calcium / Q000378:metabolism*; D002413:Cations, Divalent; D006801:Humans; D008297:Male; D012661:Semen / Q000032:analysis / Q000378:metabolism*
D002413:Cations, Divalent; D002118:Calcium