Changes in intracellular calcium of porcine sperm during in vitro incubation with seminal plasma and a capacitating medium.
The intracellular free Ca2+ concentration in ejaculated, porcine sperm was determined with a fluorescent, Ca2(+)-specific probe, Fura 2. Following suspension of sperm in a medium capable of sustaining capacitation and the acrosome reaction, the intracellular [Ca2+] increased from an initial value of about 75 nM to a peak value of 130 nM, after about 4 to 5 h of incubation. Within this period of time, a peak value of 246 nM was attained when sperm was incubated in seminal plasma. Ca2+ uptake is presumably not associated with membrane potential-dependent channels. The results indicate that a pronounced increase in intracellular free Ca2+ occurs towards the end of the incubation period when rather synchronous acrosome reactions take place in the sperm population, either in capacitating medium or in seminal plasma.
Zhou
R
R
Department of Microbiology, Michigan State University, East Lansing 48824.
Shi
B
B
Chou
K C
KC
Oswalt
M D
MD
Haug
A
A
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D004542:Ejaculation; D016257:Fura-2; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D012661:Semen / Q000502:physiology*; D013050:Spectrometry, Fluorescence; D013075:Sperm Capacitation; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism*; D013552:Swine
D000001:Calcimycin; D016257:Fura-2