Effects of pregnancy and hysterectomy on antral follicular population and growth in the ewe

Al-Gubory, Kaïs Hussain; Paly, J.; Martinet, J.

doi:10.1016/0378-4320(92)90035-c

Cited by 8 publications

(3 citation statements)

References 32 publications

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“…In ewes, it seems that suppression of follicular growth is chiefly by the developing conceptus (Bartlewski et al., 2000). Surgical removal of the gravid uterus on Day 31 after mating restored follicular growth (Al‐Gubory, Paly, & Martinet, 1992). Placental protein PSPGO is a potent inhibitor of aromatase activity and hence may affect ovarian follicle growth in pregnant ewes (Al‐Gubory et al., 1997).…”

Section: Discussionmentioning

confidence: 99%

Relationships among the corpus luteum, follicles and conceptus in sheep

Ali

Derar

2020

Anat Histol Embryol

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This study aimed to investigate the intra‐ and interovarian relationships among the corpus luteum (CL), the largest follicle (LF) and follicular population in non‐pregnant and between the conceptus and ovarian structures in pregnant ewes. In experiment 1, the follicular and luteal structures were examined in 538 reproductive systems of non‐pregnant Awassi ewes. The follicular population was categorised into small (SF), medium (MF) and large (LF) groups. Inter‐relationships between CL and follicular population and between LF and subordinate follicles were determined. In experiment 2, the location and number of conceptuses were identified and correlated with the ovarian structures in 58 reproductive systems of pregnant ewes. Effects of pregnancy status, stage of pregnancy, pregnancy side and conceptual number on follicular population were determined. The results showed that the right ovary was more active than the left ovary. CL had intraovarian positive effect on the number of medium and large follicles. LF had no local suppressive effect on the subordinate follicles. Side and stage of pregnancy and the conceptual number did not affect the follicular population. Accordingly, it can be concluded that the LF has no local suppressive effect on the subordinate follicles. The CL has intraovarian positive effect on the follicular population. Follicular population does not show remarkable changes during the first term of pregnancy. The present study probably provides information which may help in the understanding of the ovarian dynamics during pregnancy in sheep.

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Section: Discussionmentioning

confidence: 99%

Relationships among the corpus luteum, follicles and conceptus in sheep

Ali

Derar

2020

Anat Histol Embryol

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“…The reproductive tract was exteriorized through a midventral incision and the CL of each ewe were marked with Indian ink for subsequent identification. Hysterectomy was performed as described previously (2). The ewes that underwent sham operation were laparotomized and the uterus and ovaries were exteriorized and manipulated.…”

Section: Experimental Designmentioning

confidence: 99%

“…These investigations have shown that follicular growth decreases progressively with advancing pregnancy, and the largest follicles never exceed a diameter larger than 3 mm and 2 mm during the last month of pregnancy in ovaries of cattle and sheep respectively. In the ewe, hysterectomy performed on day 30 of pregnancy allows the maintenance of corpus luteum (CL) structures and progesterone secretion (2,3) at least until day 120 post-mating and subsequently enhances follicular growth, which is characterized by the presence on day 120 post-mating of healthy follicles larger than 3 mm (2), without changes in follicle-stimulating hormone (FSH) and luteinizing hormone (LH) secretion (3). These findings suggest that the gravid uterus and/or the fetoplacental unit exert a suppressing action at the ovarian level, thereby preventing the development of large healthy follicles during late pregnancy.…”

Section: Introductionmentioning

confidence: 99%

The secretory patterns of growth hormone in pregnant and hysterectomized ewes

Al-Gubory

Bolifraud

Kann

et al. 1999

European Journal of Endocrinology

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This work was undertaken to determine the secretory patterns of GH during pregnancy, and to evaluate the effect, if any, of hysterectomy during early pregnancy on subsequent secretion of GH in ewes. The concentrations of GH were determined in the plasma of jugular blood samples collected at 15-min intervals during a 6-h period on days 20, 40, 60, 80, 100 and 120 post-mating, and three times per week between days 29 and 120 post-mating from 5 pregnant ewes and from 5 ewes from which the gravid uterus was removed on day 30 post-mating. A pulse analysis program (Pulsar) was used to analyse the secretory patterns of GH in individual profiles of the serial sampling period. In the two groups of ewes, peripheral concentrations of GH fluctuated in an episodic manner during the frequent blood sampling of any stage of the post-mating period examined. The overall GH concentrations, the basal GH concentrations, the frequency and the amplitude of GH pulses remained fairly stable between days 20 and 120 post-mating in the two groups of ewes. The parameters of GH secretion were not different between the two groups of ewes. The secretory patterns of GH, as determined in plasma of blood collected three times per week between days 29 and 120 post-mating were also not different between the two groups of ewes.In conclusion, results of this study show that (i) the pulsatile secretion of GH does not change as pregnancy advances, and (ii) hysterectomy performed during early pregnancy does not subsequently affect the secretory patterns of GH. These findings suggest that the gravid uterus and/or the fetoplacental unit secretory products are unlikely to be involved in the control of GH secretion during pregnancy in the ewe.

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