Regulation of uterine immune function during the estrous cycle and in response to infectious bacteria in sheep.

Ramadan, Abeer; Johnson, Gordon; Lewis, Gregory S.

doi:10.2527/1997.7561621x

Cited by 51 publications

(63 citation statements)

References 31 publications

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“…It is also known that endometritis prevents release of luteolytic PGF2a from the uterus [21] and often induces a persistent corpus luteum [32]. Our data showed that the number of cows with a persistent corpus luteum in the ovulated and anovulated groups were identical.…”

Section: Discussionsupporting

confidence: 69%

Relationship between the First Ovulation within Three Weeks Postpartum and Subsequent Ovarian Cycles and Fertility in High Producing Dairy Cows

Kawashima

Kaneko

Montoya

et al. 2006

Journal of Reproduction and Development

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Abstract. The aim of this study was to investigate the relationship between the first ovulation within 3 weeks postpartum and subsequent ovarian cycles and fertility in high producing dairy cattle in Hokkaido, Japan. In Experiment 1, 110 cows (44 primiparous and 66 multiparous) were used to determine the effects of the first ovulation within 3 weeks postpartum on subsequent ovarian cycles. Milk samples were collected twice weekly from 7 to 100 days postpartum. The first ovulation was identified by an increase in milk progesterone (P4) to more than 1 ng/ml within 3 weeks postpartum. The numbers of cows showing ovulation and anovulation within 3 weeks postpartum were 31 (70.5%) and 13 (29.5%) in the primiparous cows and 35 (53.0%) and 31 (47.0%) in the multiparous cows, respectively. The patterns of ovarian resumption after calving were classified into two types (normal ovarian cycles and abnormal ovarian cycles) on the basis of milk P4 concentrations. Initiation of normal ovarian function in cows ovulated within 3 weeks postpartum occurred earlier than in anovulated cows regardless of the number of calvings (primiparous, 27.8 days vs. 44.4 days; multiparous, 30.6 days vs. 55.7 days; P<0.01). Out of the multiparous cows that ovulated within 3 weeks postpartum, initiation of normal ovarian function followed by a normal luteal phase was earlier than when it was followed by an abnormal luteal phase (25.5 days vs. 40.4 days; P<0.05). Milk P4 concentrations after the first ovulation were lower than those after the second ovulation in both the primiparous and multiparous cows (P<0.05). In Experiment 2, 22 multiparous cows were used to determine the effects of the first ovulation within 3 weeks postpartum on subsequent fertility. Blood samples were collected once a week from 0 to 3 weeks postpartum. The interval from parturition to first service in ovulated cows was shorter than in anovulated cows (68.4 days vs. 94.8 days; P<0.05). The conception rate by 100 days after calving tended to be higher in ovulated cows than in anovulated cows (50.0% vs. 16.7%, P=0.09). In conclusion, our data strongly suggests that ovulation within 3 weeks postpartum is a crucial phenomenon for subsequent resumption of ovarian function and conception, and thus it can be used as an index of subsequent reproductive performance.

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Section: Discussionsupporting

confidence: 69%

Relationship between the First Ovulation within Three Weeks Postpartum and Subsequent Ovarian Cycles and Fertility in High Producing Dairy Cows

Kawashima

Kaneko

Montoya

et al. 2006

Journal of Reproduction and Development

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“…In such events, intensive therapy is not always successful. The main cause of these failures is loss of the contraction ability of the uterine muscular layer (Olson et al 1984;Hussain 1989;Hussain and Daniel 1992;De Winter et al 1995;Ramadan et al 1997).…”

Section: Contractile Activity Uterus Endometritis Pge 2 Pge 2 -Amentioning

confidence: 99%

Participation of Prostaglandin E2 in Contractile Activity of Inflamed Porcine Uterus

et al. 2010

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The aim of our study was to estimate the participation of prostaglandin E 2 (PGE 2 ) in the contractile activity of inflamed porcine uterus. On day 3 of the oestrous cycle, 50 ml of saline or 50 ml of Escherichia coli suspension, containing 10 9 colony-forming units/ml, was injected into each uterine horn in the control or experimental group, respectively. Seven days later the uteri were collected. Endometritis developed in all bacteria-inoculated gilts. Endometrium/myometrium and myometrium strips were incubated with PGE 2 alone or together with PGE 2 receptor (EP) subtypes (EP 2 , EP 4 , EP 1 and EP 3 ) blockers: AH 6809 (BEP 2 ), ONO-AE 2 (BEP 4 ), ONO-AE 3 -240 (BEP 1 ) and SC19220 (BEP 3 ), respectively. In the control group, PGE 2 (10 -8 and 10 -7 M) increased the intensity of contractions in endometrium/myometrium, and at the higher dose in myometrium. PGE 2 (10 -8 M) decreased the contraction intensity of the strips from inflamed uteri. After the use of BEP 2 , PGE 2 (10 -7 M) increased the values of this indicator in endometrium/myometrium and myometrium from the control gilts. In these animals, PGE 2 (10 -8 M) in the presence of BEP 4 reduced the contraction intensity in endometrium/myometrium. In the bacterial group, PGE 2 (10 -8 M) in the presence of BEP 2 and BEP 4 enhanced the intensity of contractions in myometrium. Similar reaction was evoked by PGE 2 (10 -7 M) in endometrium/myometrium of the inflamed uteri in the presence of BEP 4 . The intensity of contractions in myometrium from the inflamed uteri significantly decreased after the use of BEP 1 and PGE 2 (10 -7 M). PGE 2 (10 -7 M) administered after BEP 3 , significantly decreased the intensity of contractions in myometrium of the control gilts. These results show that PGE 2 decreases the contraction intensity of inflamed porcine uteri. Further studies are needed to closely determine the role of PGE 2 and other prostanoids in the contractile activity of inflamed uterine tissue.

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“…O ne of the long-standing enigmas of reproductive biology is why the fetus is not rejected by the mother's immune system (1)(2)(3). Many explanations for this phenomenon have been proposed and tested, including the idea of paternal antigen sequestration and reduced MHC expression (4,5), the possibility of local immune changes in the uterus (6,7), and a potential maternal shift from Th1 to Th2 immune responses (8)(9)(10). Although each of these mechanisms appears to play some role in protection of the fetus from the maternal immune system, none has been directly shown to be required.…”

mentioning

confidence: 99%

Progesterone receptors in the thymus are required for thymic involution during pregnancy and for normal fertility

Tibbetts

DeMayo

Rich

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

149

123

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Thymocyte development is reported to be inhibited by pregnancy, although the impact of this effect on fertility is unknown. We demonstrate, using progesterone receptor null mutant mice, that the inhibitory effects of pregnancy hormones on T cell development require the presence of functional progesterone receptor (PR). A combination of hysterectomy, thymic immunohistochemistry, and transplant studies reveals that local expression of PR in thymic stromal cells is specifically required for thymic involution to occur. These cells, under the influence of progesterone, block T cell development at the early pre-T cell (CD3 ؊ CD44 ؉ CD25 ؉ ) stage of development via a paracrine mechanism. In addition, age-related thymic involution is shown to occur by a separate PR-independent mechanism. Finally, pregnancy studies with thymic transplants from progesterone receptor null mutant mice to wild-type female recipients demonstrate that thymic stromal PR is required for normal fertility. Together, these observations provide evidence for a PR-dependent paracrine mechanism that blocks very early T cell lymphopoiesis during pregnancy and is essential for normal fertility. O ne of the long-standing enigmas of reproductive biology is why the fetus is not rejected by the mother's immune system (1-3). Many explanations for this phenomenon have been proposed and tested, including the idea of paternal antigen sequestration and reduced MHC expression (4, 5), the possibility of local immune changes in the uterus (6, 7), and a potential maternal shift from Th1 to Th2 immune responses (8-10). Although each of these mechanisms appears to play some role in protection of the fetus from the maternal immune system, none has been directly shown to be required. It now appears that pregnancy may in fact have many redundant mechanisms acting both systemically and at the maternal-fetal interface to protect the fetus from the mother's immune system.One particularly interesting effect of pregnancy on the maternal immune system is a general blockade of lymphocyte development. This blockade manifests itself grossly in the form of thymic involution and bone marrow involution. Involution of the thymus, the site of T cell differentiation, has long been recognized to occur during pregnancy in a number of species including rat, mouse, and human (11-13) and may be mimicked by the administration of the female sex hormones estrogen (E) and progesterone (P), although the relative contributions of the two hormones are controversial (14,15). Although the functional importance of pregnancy-induced thymic involution remains unknown, the fact that it has been observed in all mammals that have been examined has led to the speculation that reduced or altered output of mature T cells by the thymus could be an important component of maternal immune regulation. It also has been reported that bone marrow, the site of B lymphocyte development, undergoes an involution process similar to that occurring in the thymus during pregnancy. The result is a specific block to B cell de...

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Regulation of uterine immune function during the estrous cycle and in response to infectious bacteria in sheep.

Cited by 51 publications

References 31 publications

Relationship between the First Ovulation within Three Weeks Postpartum and Subsequent Ovarian Cycles and Fertility in High Producing Dairy Cows

Relationship between the First Ovulation within Three Weeks Postpartum and Subsequent Ovarian Cycles and Fertility in High Producing Dairy Cows

Participation of Prostaglandin E2 in Contractile Activity of Inflamed Porcine Uterus

Progesterone receptors in the thymus are required for thymic involution during pregnancy and for normal fertility

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