261 EVALUATION OF TWO GAS MIXTURES, ADDITION OF N-ACETYLCYSTEINE, AND LIPOPEROXIDATION LEVELS IN PORCINE EMBRYOS PRODUCED IN VITRO

In vitro embryo development can be affected by many different factors, such as incubation atmosphere, which can cause oxidative stress. In this study the effect of 2 gas mixtures and the addition of the antioxidant agent N-acetylcysteine (NAC) on porcine embryos produced in vitro and lipoperoxidation (LPO) were evaluated. Ovaries collected from slaughtered gilts were aspirated to obtain oocytes, to be matured and fertilized in vitro. In experiment 1 (E1), putative zygotes were cultured in NCSU-23 medium at 38.5°C in humidified air and randomly allocated to each of the following atmospheres: conventional atmosphere (CA: 5% CO2 in air) and modified atmosphere (MA: 5% CO2, 5% O2, 90% N2). In experiment 2 (E2), zygotes were incubated in CA or MA and cultured in NCSU-23 with 2.5 mM NAC. In experiment 3 (E3), embryos produced in E1 and E2 were used to evaluate LPO with the TBARS method: embryos were sonicated, then 300 μL of distilled water and 680 μL of thiobarbituric acid were added and heated at 95°C for 20 min in a water bath. The resulting reaction was read by spectrophotometry at 532 nm. Final concentration was expressed in micromoles of TBARS/embryo (μMTE). Five days after IVF, embryos were evaluated to determine their development to the morula stage. Data from each experiment were transformed using arcsine square root function before analysis, and means were compared using ANOVA. For E1, 954 oocytes were used, 475 for CA and 479 for MA, in 5 replicates. The percentage of cleaved embryos was significantly higher in MA (300/479, 63%) compared with CA (245/475, 52%) (P < 0.05). The percentage of morulae obtained was higher in MA (127/479, 27%) than in CA (80/475, 17%) (P < 0.05). In E2, 936 oocytes were used, 470 for CA NAC and 466 for MA NAC, in 5 replicates. There were no differences in the percentages of cleaved embryos in MA NAC (250/466, 54%) compared with CA NAC (243/470, 52%), and morulae in MA NAC (86/466, 18%) compared with CA NAC (81/470, 17%) (P > 0.05). In E3, during the first 24 h of culture the embryos in CA NAC had lower LPO concentrations (0.029μMTE) (P < 0.05) than in CA (0.059μMTE), MA (0.057μMTE), and MA NAC (0.054μMTE). In morulae, a higher concentration of LPO was observed in the CA group (0.103μMTE) compared with MA (0.083μMTE), CA NAC (0.085μMTE), and MA NAC (0.081μMTE). A correlation analysis between morulae development and LPO in CA and MA, with or without NAC, did not show a significant relationship (r = 0.20; P > 0.05). It is concluded that MA improves the development of in vitro-derived porcine embryos; that NAC treatment did not cause differences in any stage of embryo development, probably meaning that the embryo has its own defensive mechanisms against LPO, and therefore that NAC is not a good antioxidant for porcine embryos, or that it does not work well at the dosage and/or in the culture medium used; that the embryos exposed to CA and MA showed higher LPO that the groups with NAC, indicating that the addition of NAC tends to decrease LPO; and that LPO could be a good indicator of embryo viability. We thank CONACYT Mexico for the graduate student’s scholarship.

Melatonin and testicular function: characterization of binding sites for 2-[125I]-iodomelatonin in immature rat testes

Melatonin-binding sites in membrane preparation immature rat testes were demonstrated by utilizing 2-[125I]-iodomelatonin as a radioligand. Binding at these sites was found to be reversible, saturable, specific and of, high affinity. Scatchard analysis of the specific binding revealed an equilibrium binding constant (kd) of 215 +/- 23 pmol/L and a total number of binding sites (Bmax) of 0.94 +/- 0.1 fmol/mg protein. The Hill coefficient of 1.0 suggests a single class of 2-[125I]-iodomelatonin-binding site in the rat testes. The Kd value determined from kinetic analysis was 179 pmol/L, which is in close agreement with the value determined from equilibrium studies. In competition studies, the order of pharmacological affinity for 2-[125I]-iodomelatonin binding sites in the rat membrane testes was: melatonin > 6-hydroxymelatonin > N-acetylserotonin > 5-hydroxyindole-3-acetic acid > 5-hydroxytryptamine > 5-hydroxy-L-tryptophan > tryptamine > > 5-methoxytryptamine, 5-methoxyl-DL-tryptophan, D-L-tryptophan. The 2-[125I]-iodomelatonin binding was markedly reduced by guanine nucleotides; treatment with nonhydrolyzable GTP analog guanosine 5'-O-(3-thiotriphosphate) caused a 10-fold decrease in receptor affinity. In this paper, we report evidence indicating the presence of binding sites in immature rat tests, suggesting a possible direct role of melatonin on testicular steroidogenesis.

The client's view of high-quality care in Santiago, Chile

The meaning of quality of care for the women who receive reproductive health services at a family planning and maternal and infant care clinic in Santiago, Chile, was examined to describe the clinic's service from the women's point of view. A participatory research project with the staff of the clinic was conducted. The central part of that study, reported here, consisted of interviews with 60 of the 330 women who came to the clinic during two weeks in June 1991. The women defined high quality of care as "being treated like a human being." Among specific elements of care they identified were cleanliness, promptness and availability of service, time made available for consultation, learning opportunities for themselves and their partners, and cordial treatment. Clients' view of quality of care must be supplemented by professional judgments about how well services meet clients' needs. But the client's view is determinant if improvements are to result in greater acceptance and sustained use of the services offered. The issues identified by the clients involve only minor costs for the clinic.