Superovulation and embryo collection in nulliparous Boer goat does immunized against a recombinant ovine alpha-subunit inhibin

With the purpose of eliciting a superovulatory response, 12 adult nulliparous Boer goat does were actively immunized against a recombinant a-subunit of ovine inhibin (roIHN-alpha; two injections of 100 mg 4 weeks apart). Another 12 control Boer goat does were treated with physiological saline and acted as controls. One year later the immunized animals were boostered by the administration of another dose (100 mg) of the immunogen. Following treatment, blood samples were collected twice weekly for the periods of 16 and 12 weeks, respectively, to monitor the inhibin binding ability with the aid of a radio-tracer binding assay. Throughout the experiment, estrus detection was conducted twice daily with the aid of an aproned intact buck. From the first day after treatment to 48 h after standing estrus, ovarian activity was monitored daily by transrectal ultrasonography. On alternate estrous cycles, does were mated and 6 days later flushed transcervically to recover embryos. All goats treated with the roIHN-alpha produced antibodies reactive to the native bovine inhibin tracer-the titre increasing from 2.9 +/- 0.4 to a maximum of 21.9 +/- 2.9% binding after the second injection. The antibody titre gradually subsided over the next 16 weeks. The booster injection restored an elevated antibody titre (11.7 +/- 0.4%), which was maintained until the end of the sampling period 12 weeks later. In the control goats only trace amounts of antibody were recorded throughout the trial. In the roIHN-alpha-immunized goats the number of follicles reaching a diameter of > 4 mm was 14.6 +/- 1.2 per doe. A positive correlation was recorded between the follicle number and antibody titre (r=0.61; P < 0.01). The number of follicles ovulating per doe (6.9 +/- 0.7) followed the same tendency-however, the proportion decreased with increasing follicle numbers. A relatively weak correlation was recorded between the inhibin binding ability and number of ovulations (r=0.27; P < 0.05). In the control goats the majority (92%) of follicles exceeding 4 mm in diameter ovulated (2.5 +/- 0.1 follicles/doe). Embryo collection proved unsatisfactory (42% versus 39% recovery for immunized and control animals, respectively)-presumably because the uterine lumen of the nulliparous does was too narrow to permit effective flushing. In the group of immunized goats the occurrence of short estrous cycles (< 15 days) recorded was 34% versus only 6% in the controls. Overall, immunization of goats against roIHN-alpha led to an almost six-fold increase in number of ovarian follicles, a three-fold increase in ovulations and, despite the low recovery rate, a more than three-fold increase in ova or embryos recovered. It may be concluded that treatment of female goats with roIHN-alpha leads to an inhibin antibody response, accompanied by enhanced ovarian activity. The response was, however, accompanied by a large proportion of retained follicles and a high incidence of short estrous cycles. These problems need to be further investigated before rendering the method fit for application in embryo transfer programs in goats. (C) 2007 Elsevier B.V. All rights reserved.

Increased apoptosis in first trimester extravillous trophoblasts from pregnancies at higher risk of developing preeclampsia

Preeclampsia complicates 5 to 10% of pregnancies and is a leading cause of maternal and fetal mortality and morbidity. Although the cause is unknown, inadequate invasion and remodeling of maternal uterine arteries by extravillous trophoblasts (EVTs) in the first trimester is a common feature. Uterine spiral artery resistance as detected by Doppler ultrasound is commonly used in the second trimester to identify pregnancies destined to develop preeclampsia. Correlation between high uterine resistance and the failure of trophoblast invasion has been reported as early as 12 weeks. However, the reason for this failure has not been established. Understanding the processes involved would significantly improve our diagnostic potential. In this study, we correlated increased first trimester uterine artery resistance with a biological abnormality in trophoblast function. EVTs derived from high-resistance pregnancies were more sensitive to apoptotic stimuli than those from normal-resistance pregnancies. Survival of EVTs from high-resistance pregnancies could be increased by nitric oxide, whereas inhibition of nitric oxide in cells from normal-resistance pregnancies increased apoptotic sensitivity. This predates the onset of symptoms by several weeks and provides evidence for a mechanism responsible for the incomplete uterine vessel remodeling and the differences in artery resistance between preeclamptic and normal pregnancies.

Functional and molecular characterization of Tachykinins and tachykinin receptors in the mouse uterus

The aim of this study was to analyze the function and expression of tachykinins, tachykinin receptors, and neprilysin (NEP) in the mouse uterus. A previous study showed that the uterotonic effects of substance P (SP), neurokinin A (NKA), and neurokinin B (NKB) in estrogen-treated mice were mainly mediated by the tachykinin NK, receptor. In the present work, further contractility studies were undertaken to determine the nature of the receptors mediating responses to tachykinins in uteri of late pregnant mice. Endpoint and real-time quantitative RTPCR were used to analyze the expression of the genes that encode the tachykinins SP/NKA, NKB, and hemokinin-1 (HK-1) (Tac1, Tac2, and Tac4); and the genes that encode tachykinin NK1 (Tacr1), NK2 (Tacr2), and NK3 (Tacr3) receptors in uteri from pregnant and nonpregnant mice. The data show that the mRNAs of tachykinins (particularly NKB and HK-1), tachykinin receptors, and NEP are locally expressed in the mouse uterus, and their expression changes during the estrous cycle and during pregnancy. The tachykinin INK, receptor is the predominant tachykinin receptor in the nonpregnant and early pregnant mouse and may mediate tachykinin-induced uterine contractions in the nonpregnant mouse. The tachykinin NK, receptor is predominant in the late pregnant mouse and is the main receptor mediating uterotonic responses to tachykinins at late pregnancy. The tachykinin NK, receptor is expressed in considerable amounts only in uteri from nonpregnant diestrous animals, and its physiological significance remains to be clarified.

Oestrogenic activity of benzylparaben

Previous work has demonstrated that the alkyl esters of p-hydroxybenzoic acid (parabens) possess oestrogenic activity, which increases with length of alkyl chain from methylparaben to n-butylparaben and with branching in the alkyl chain from n-butylparaben to isobutylparaben. This study reports on the oestrogenic activity of benzylparaben in a variety of assays in vitro and in vivo. Benzylparaben was able to displace [H-3]oestradiol from cytosolic oestrogen receptor (ER) of MCF7 human breast cancer cells by 22% at 1000-fold molar excess, by 40% at 10000-fold molar excess, by 57% at 100000-fold molar excess and by 100% at 1000000-fold molar excess. It was able to increase expression of a stably transfected oestrogen responsive reporter gene (ERE-CAT) in MCF7 cells after 24 h at 10(-5)M/10(-4)M and after 7 days at 10(-6)M/10(-5)M/10(-4)M. Proliferation of MCF7 cells could be increased by 10(-6)M/10(-5)M benzylparaben and this could be inhibited by 10(-7)M pure anti-oestrogen ICI 182,780, indicating that growth effects were ER mediated. Further evidence for ER-mediation was provided from the ability of benzylparaben to increase the growth of a second oestrogen-dependent human breast cancer cell line ZR-75-1, but not the oestrogen-insensitive NIDA-MB-231 cell line. When tested in the presence of 10(-10)M 17beta-oestradiol, benzylparaben gave no antagonist response on the growth of either MCF7 or ZR-75-1 cells. Finally, benzylparaben could increase uterine weight in the immature mouse following topical application of three daily doses of 33 mg to dorsal skin. These results demonstrate that the oestrogenicity of methylparaben can be increased by the addition of an aryl group as well as by lengthening or branching the alkyl grouping. Copyright (C) 2003 John Wiley Sons, Ltd.