Progesterone [KLH]

This study examined the effect of administering an additional dose of prostaglandin F2 alpha (PGF2 alpha), in a fixed-time artificial insemination protocol (FTAI), on the fertility of female Nellore cattle. Two experiments were carried out: the first (Experiment I) took place in the state of Tocantins and the second (Experiment II) in the state of Para, Brazil. In Experiment I (E1), 80 cows were used in three treatments (T1, T2 and T3) in which all received the same FTAI protocol. In T1 (n = 29), the cows received 12.5 mg of Dinoprost on day 9; in T2 (n = 28), they received the additional dose on day 10; and in T3 (n = 23; control group), the animals did not receive the additional PGF2 alpha dose. Experiment II consisted of 147 bovine females distributed into two treatment groups, namely, T1 - 72 animals receiving the same protocol as T1 of E1; and T2 - 75 animals receiving the same protocol as T3 of E1. Statistical analysis was performed using SAS software, applying the PROC NPARWAY procedure for E1, and means were compared by the Wilcoxon test at the 5% significance level. In Experiment II, the data were subjected to analysis of variance by PROC GLIMMIX and means were compared by the T test at the 5% significance level. The following pregnancy rates were obtained in Experiment I: T1 - 62.06% (18/29); T2 - 57.14% (16/28); and T3 - 52.17% (12/23), with no significant difference observed between treatments. In Experiment II, pregnancy rate in T1 was 66.67% (48/72), whereas in T2 it was 41.33% (31/75), with a significant difference detected (P < 0.05). An additional dose of PGF2 alpha provides an increase in pregnancy rate in Nellore females.

One of the major problems of success in infertility treatment could depend on the understanding how the potential factors may affect the conception. The aim of this study was to evaluate present understanding of such factors or hormonal causes that may induce infertility. We studied the interactions between the two menstrual cycle hormones i.e., cortisol (COR) and prolactin (PRL), along with the ultrasonographic ovulation parameters in a group of N = 205 women with diagnosed infertility. The control group consisted of N = 100 women with confirmed fertility. In both groups, follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-Mullerian hormone (AMH), thyroid stimulating hormone (TSH), PRL, COR were examined on the third day of the cycle, and estradiol (E2), progesterone (P), and COR were examined during ovulation and 7-days afterwards. In the infertile group, higher levels of PRL and COR were observed than that of in the control group. Cortisol levels at all phases of the menstrual cycle and PRL negatively correlated with E2 secretion during and after ovulation, thus contributed to the attenuation of the ovulatory LH surge. Infertile women who conceived presented with higher levels of E2 during and after ovulation, higher P after ovulation, and thicker endometrium than that of the women who failed to conceive. In conclusion, elevated secretion of COR and PRL in infertile women impairs the menstrual cycle by decreasing the pre-ovulatory LH peak and E2 and postovulatory E2 levels that affect the endometrial growth, and consequently reduce the chances to conceive.