Effect of FSH and progesterone on human spermatozoa cytosolic calcium.
Ejaculated spermatozoa must undergo a number of modifications before fertilizing the oocyte: among these the capacitation and the acrosome reaction. Calcium signals play an essential role in these functional and structural modifications. Mature spermatozoa have few organelles and a very small cytoplasmic volume but maintain the homeostasis of [Ca(2+)](c) with great accuracy. We study Ca(2+) mobilization in human spermatozoa exposed to FSH and progesterone by measuring the [Ca(2+)](c) with the FURA-2AM method and report for the first time that the exposure to FSH (up to 98ng/ml) produced an increase of [Ca(2+)](c) to an extent comparable to that observed with 1muM progesterone. FSH and progesterone increase the spermatozoa [Ca(2+)](c) by acting primarily on calcium entry from the external medium. The effects of the two hormones on [Ca(2+)](c) were similar but not identical; the pre-treatment of progesterone blocks the effects of FSH, but not vice-versa. The increase of [Ca(2+)](c) due to FSH was more sensitive to nifedipine (VOCCs inhibitor) than that of progesterone. The effects of these hormones on calcium homeostasis may be relevant for sperm activation.
Arienti
Giuseppe
G
Laboratory of Biochemistry, Department of Internal Medicine, Via del Giochetto, 06127 Perugia, Italy.
Mazzoni
Michela
M
Spapperi
Chiara
C
Saccardi
Carla
C
Palmerini
Carlo A
CA
D000328:Adult; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism*; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D006801:Humans; D008297:Male; D011374:Progesterone / Q000378:metabolism*; D013094:Spermatozoa / Q000378:metabolism*
D011374:Progesterone; D005640:Follicle Stimulating Hormone; D002118:Calcium