Sexual behavior during successive ejaculations in bonnet and pigtail macaques.
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The direct overlay technique with iodinated calmodulin on boar sperm fractions evidenced a strong bond in the 45,000 molecular weight, which is the region recognized by anti-actin antibodies. This result and the close codistribution of the two staining patterns for calmodulin and actin with immunofluorescence and immunoelectronmicroscopy suggest a possible interaction between calmodulin and actin in boar sperm.
Four experiments were replicated 1) to establish dose-response relationships between lysophosphatidylcholine (LPC), sperm motility, and the acrosome reaction (AR), 2) to evaluate the influence of rabbit serum (RS) on these endpoints, 3) to compare buck differences in induction of the AR, and 4) to examine fertilizing ability in vitro of sperm tested under the first three objectives. Semen was collected from Dutch-belted rabbits, washed once by centrifugation, resuspended, and preincubated for 2 or 4 hr in a chemically defined medium (DM), DM plus 20% RS, or BSA-free DM plus 20% RS at 37 degrees C. At the end of preincubation LPC was added to the preincubated sperm at concentrations of from 0 to 100 micrograms/ml. Sperm were examined .5-4 hr later for AR and sperm motility. For in vitro fertilization, sperm and ova were coincubated in DM up to 24 hr after insemination and in a more complex medium for another 24 hr. Addition of LPC to 4-hr-preincubated sperm was more effective for inducing the AR than addition to 2-hr-preincubated sperm. A significant increase (P less than .05) in the AR occurred in 15 and 30 min following exposure to 100 and 80 micrograms of LPC per ml, respectively, but the higher concentration of LPC decreased sperm motility. Addition of 20% RS to DM with or without BSA surprisingly inhibited the AR but maintained sperm motility, as expected. Bucks differed (P less than .05) in the initial percentage and the induced percentage of AR sperm. For the AR the optimal concentration of LPC per ml was 80 micrograms, but for in vitro fertilization 60 micrograms tended to be superior.
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PURPOSE: To correlate levels of cholesterol (CH), calcium (Ca2+), and mitochondrial activity (MA) with the standard semen parameters and to compare them between fertile and infertile men. METHODS: We studied 151 semen samples from infertile (n = 60) or fertile (n = 91) males. Basic sperm parameters were analyzed. Ca2+ and CH concentrations on seminal plasma were determined by enzymoimmunoanalysis. Intracellular Ca2+ and CH concentrations in the sperm plasma membrane and mitochondrial activity by fluorometry. RESULTS: There was a significant positive correlation between sperm membrane CH and sperm morphology. Intracellular Ca2+ was lower in infertile patients compared to fertile. No differences were found regarding Ca2+ and CH concentrations in seminal plasma. MA is directly and strongly related with sperm motility. CONCLUSIONS: Intracellular concentrations of Ca2+ and the proportion of CH in the sperm membrane are two important markers of the sperm quality due to its direct relationship with sperm morphology and fertility potential.
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Gossypol, a promising male contraceptive isolated from cottonseed oil, inhibits spermatozoal motility. This antimotility effect accompanies a biphasic change in the spermatozoal respiratory rate: a stimulation at low concentrations and an inhibition at high concentrations. With various respiratory inhibitors, gossypol was shown to take effect by the uncoupling of the respiratory chain and the oxidative phosphorylation. The implication of this uncoupling action in the strategy of producing an ideal gossypol-like male contraceptive is discussed.