In vitro effects of beta-carotene for the motility, ATP, and intracellular free Ca2+ concentrations of fowl spermatozoa.

摘要

The motility of intact fowl spermatozoa was vigorous at 25deg C, but decreased gradually following the addition of 0-100μM beta-carotene in a dose-dependent manner. Even in the presence of stimulators of fowl sperm motility, such as Ca2+ or calyculinA, the motility of intact spermatozoa at both 25 and 40deg C remained inhibited following the addition of beta-carotene. Under all of these circumstances, sperm ATP concentrations were not reduced by the addition of beta-carotene. Moreover, the motility ofdemembranated spermatozoa was not inhibited by the addition of the same concentrations of beta-carotene. No changes in intracellular free Ca2+ concentrations, measured by means of a fluorescent Ca2+ indicator, fura-2, were observed in intact beta-carotene-treated spermatozoa. These results suggest that beta-carotene is involved in the inhibition of the flagellar movement of fowl spermatozoa without change in energy production, and that the target of beta-carotene might be present in the cytoplasmic matrix and/or the plasma membrane, but not retained in the axoneme and/or accessory cytoskeletal components.