Calcium efflux mechanism in sperm mitochondria
| Autor: | Haim Breitbart, Michal Gruberger, Sara Rubinstein |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone
Male Spermatozoon Digitonin Atractyloside Mersalyl Phosphates chemistry.chemical_compound Cyclosporin a Animals Lactic Acid Mitochondrion Uniporter Inner mitochondrial membrane Calcium efflux Molecular Biology Membrane potential Sheep Voltage-dependent calcium channel Chemistry Uncoupling Agents Calcium-Binding Proteins Cell Biology Ruthenium Red Spermatozoa Mitochondria Adenosine Diphosphate Mitochondrial permeability transition pore Biochemistry Biophysics Cyclosporine Lactates Calcium Efflux Calcium Channels Mitochondrial ADP ATP Translocases |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Molecular Cell Research. 1312(2):79-84 |
| ISSN: | 0167-4889 |
| DOI: | 10.1016/0167-4889(96)00022-5 |
| Popis: | This paper reports an investigation on calcium efflux mechanism in ram sperm mitochondria. Energized sperm mitochondria take up Ca2+ via the ruthenium-red sensitive uniporter, and possess a ruthenium-red insensitive efflux mechanism. Extramitochondrial Na+ did not affect the rate of Ca2+ efflux indicating that Na+Ca2+ exchange mechanism is not involved. Depolarization of inner mitochondrial membrane induced by the uncoupler carbonylcyanide-p-trifluoromethoxyphenyl hydrazone (FCCP) or by the organomercurial SH-reagent mersalyl, causes high stimulation in Ca2+ efflux. This stimulated Ca2+ efflux determined in the presence of ruthenium-red and phosphate, is not inhibited by cyclosporin A (CSA), indicating that mitochondrial permeability transition pore (MTP) is not involved in this Ca2+ efflux mechanism. The stimulated Ca2+ efflux is inhibited by ADP or atractyloside suggesting that the Ca2+ transport mechanism might be intrinsic to the ADP/ATP carrier (AAC). Thus, the data indicate that sperm mitochondria contain a Ca2+ efflux mechanism operated via AAC and regulated by mitochondrial membrane potential and by ADP concentration. |
| Databáze: | OpenAIRE |
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