Evidence against a functional ATP-dependent calcium extrusion mechanism in bovine epididymal sperm

Molecular Reproduction and Development
Srinivasan VijayaraghavanK Hermsmeyer

Abstract

Bovine epididymal sperm resuspended in ionic buffers take up relatively large amounts of calcium. This uptake, which is almost entirely mitochondrial, apparently bypasses the sperm cytosol. The direct mitochondrial loading is an unusual aspect of sperm calcium uptake, which suggests that the plasma membrane region surrounding the mitochondria should be highly permeable to calcium, whereas the membrane domains surrounding the head and tail regions of sperm should be impermeable. This study was undertaken to determine the role of a plasma membrane calcium ATPase in sperm calcium homeostasis. Kinetics of calcium (45Ca2+) uptake into intact and permeabilized caudal epididymal sperm confirmed that mitochondrial calcium uptake occurs with virtually no resistance from the surrounding plasma membrane. Cytoplasmic calcium accumulation by sperm depleted of intracellular ATP, measured in the presence of mitochondrial calcium uptake inhibitors, showed no increase upon energy depletion as would be expected if an ATP-dependent calcium extrusion mechanism were present. Furthermore, lowering the incubation temperature to further reduce the activity of the calcium ATPase in these energy-depleted sperm was also without effect on calcium accumula...Continue Reading

References

Jul 15, 1975·European Journal of Biochemistry·K C Reed, F L Bygrave
Jun 1, 1978·The Journal of Experimental Zoology·Donner F BabcockT Hutchinson
Mar 1, 1979·Developmental Biology·Donner F BabcockH A Lardy
Jan 1, 1988·Methods in Enzymology·E Carafoli
Jul 1, 1987·FASEB Journal : Official Publication of the Federation of American Societies for Experimental Biology·J San AgustinH A Lardy
Jan 1, 1987·Annual Review of Biochemistry·E Carafoli
Apr 1, 1969·The Journal of Physiology·H J Schatzmann, F F Vincenzi
Jul 27, 1983·Biochimica Et Biophysica Acta·H Breitbart, S Rubinstein
Mar 9, 1983·Biochimica Et Biophysica Acta·H BreitbartS Rubinstein
May 19, 1980·FEBS Letters·S VijayasarathyP Balaram
Aug 14, 1980·Biochimica Et Biophysica Acta·H BarrabinA F Rega
Mar 23, 1982·Biochimica Et Biophysica Acta·A CittadiniG Calviello

Citations

May 1, 1996·Molecular Reproduction and Development·S A Adeoya-Osiguwa, L R Fraser
Mar 30, 2007·Molecular Reproduction and Development·Zhide DingYonglian Zhang
Feb 21, 1997·The Journal of Biological Chemistry·Srinivasan VijayaraghavanD W Carr

Related Concepts

Ca(2+)-Transporting ATPase
Adenosine Triphosphate, Chromium Ammonium Salt
Calcium
Bos indicus
Plasma Membrane
Cell Membrane Permeability
Cold Temperature
Digitonin
Epididymis
Mitochondria

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