Altered motility of myometrium from estrous ewes after the regulation of estrus with progestagen or prostaglandin

Hawk, H. W.; Conley, H.H.

doi:10.1016/0093-691x(74)90011-9

Cited by 12 publications

(2 citation statements)

References 10 publications

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“…Progestogen administration to ewes has caused either decreased (Smith and Aalison, 1971) or increased (Rexroad and Barb, 1977) production of cervical mucus during the ensuing estrus. Regulation of estrus by either progestogen or prostaglandin alters uterine contractions, both in vivo and in vitro, during the regulated estrus (Hawk, 1973;Hawk and Echternkamp, 1973;Hawk and Conley, 1974). Either cervical mucus or contractions of the reproductive tract might act as mediators of decreased efficiency of sperm transport into the cervix.…”

Section: Discussionmentioning

confidence: 99%

Sperm Transport into the Cervix of the Ewe after Regulation of Estrus with Prostaglandin or Progestogen

Hawk¹,

Cooper²

1977

Journal of Animal Science

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Mature ewes (12 per group) were given prostaglandin F20t (PG; 10 mg intramuscularly) on day 10 of an estrous cycle, to regress corpora lutea, or on day 16, after natural corpus luteum regression. Ewes treated on day 10 or 16 were in estrus on day 12 or 17, respectively. The PG-treated and untreated ewes were mated at estrus and necropsied 2 hr later. Sperm were counted in the oviducts, the uterus and the anterior, middle and posterior segments of the cervix. Sperm numbers were reduced in all three segments of the cervices of ewes treated with PG on day 10 but not in ewes treated on day 16. The results suggest that some factor associated with shortening of the estrous cycle inhibited sperm transport. Other ewes were treated with 60 mg of medroxyprogesterone acetate (MAP) by intravaginal sponge from day 6 to 14, 6 to 22 or 14 to 22 of an estrous cycle and mated at the ensuing estrus, 2 or 3 days after MAP withdrawal. Sperm numbers in the anterior cervix 2 hr after mating were reduced in all MAP-treated ewes, and sperm numbers in the entire cervix were significantly lower in the 6 to 14 day group than in the other MAP-treated ewes. In the ewes treated from day 6 to 14, endogenous progesterone secretion was similar to that of untreated ewes through day 14, and estrous cycles averaged 16.8 days in length. Thus, MAP treatment reduced sperm numbers in the cervix Mention of products or companies in this report does not constitute endorsement by the U.S. Department of Agriculture to the exclusion of others not mentioned. 2Reproduction Laboratory, Animal Physiology and Genetics Institue, Agricultural Research Center. 3The authors express appreciation to The Upjohn Company, Kalamazoo, Michigan, for supplying the prostaglandin and medroxyprogesterone acetate and to Rosemary Rollins and D. J. Bolt of the Reproduction Laboratory for conducting the blood serum progesterone assays. regardless of whether the estrous cycle was prolonged or normal in length.

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Section: Discussionmentioning

confidence: 99%

Sperm Transport into the Cervix of the Ewe after Regulation of Estrus with Prostaglandin or Progestogen

Hawk¹,

Cooper²

1977

Journal of Animal Science

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“…The postovulatory increase of uterine and oviductal muscle contractions facilities transport of gametes and thereby enable fertilization as well support the labor. However, almost all length of pregnancy needs uterine quiescence [24,25]. It is reached by progesterone (P4) block of oxytocin (OT) receptors in the myometrium, [26] and relaxin (RLX), which directly inhibit the uterine contractions, as well it is involved in cervical dilation and relaxation of pubic symphysis [27].…”

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confidence: 99%

The Preliminary Study About the Involvement of Relaxine in Adverse Effect of Polychlorinated Biphenyls on Bovine Myometrial Contractions

Wróbel¹

2017

J Clin Mol Endocrinol

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Polychlorinated biphenyls (PCBs) are a group of synthetic xenobiotics, which were used in lots of industrial applications. Two individual congers (PCB 153 and PCB 77) belong to the most prominent environmental contaminations among PCBs, but they have opposite type of configuration and therefore they can exert a different way of action. Since PCBs increased the force of myometrial contractions, in this work, their effect on myometrial sensitivity on inhibitor of myometrial contractions (relaxine, RLX) was studied.Bovine myometrial cells and strips, and luteal cell at 4-8 month of pregnancy, were obtained accidentally in commercial abattoir. They were treated by PCB 153 and PCB 77 and mRNA expression of RLX receptor in myometrial cells and contractions of myometrial strips as well as the secretion of progesterone (P4) and oxytocin (OT) from luteal cells, were measured under their effect.Both studied congeners decreased (P<0.05) the mRNA expression of RLX receptor in myometrium. Admittedly, both PCB 77 and 153 increased (P<0.05) the basal force of contractions, while RLX showed any effect on myometrial contractions. Studied PCBs increased also (P<0.05) secretion of P4 and OT from luteal cells.It is suggested that PCBs can decreased the sensitivity of myometrium on RLX but their direct effect on RLX function have to be further investigated. Keywords: Endocrine Disruption; Pregnancy; Uterus IntroductionPolychlorinated biphenyls (PCBs) are a group of synthetic, chlorinated aryl hydrocarbons, which were extensively used in lots of industrial applications, mainly in transformers, capacitors or as hydraulic fluids, heat exchange liquids as well as plasticizers and others [1]. Because of different degree of chlorination, there are possible up to 209 congeners of PCBs. Among them, 3,3 ' ,4,4 ' -tetrachlorobiphenyl (PCB 77) is one of the most abundant PCB congeners in human milk. This congener is a non-ortho chlorine substituted with coplanar configuration and appear to exert its toxic effects via interacting with the cytosolic aryl hydrocarbon receptor (Ahr). Hence is recognized also as dioxin-like PCBs [2]. Since PCB 77 can affect the cell also through estrogen [3] and glucocorticoid receptors [4], it is recognized as a significant environmental pollutant and endocrine disruptor [3] with a wide spectrum of way of action. Admittedly 2,2',4,4', 5,5'-hexachlorobiphenyl PCB 153 is also one of the most prominent environmental contaminants, but oppositely to PCB 77 is classified as di-ortho, non-coplanar, non-dioxin congener of PCBs [5] and is known to have rather estrogenic properties [6]. Even though PCBs production and use were banned in USA and Europe more than three decades ago, they are still measured in environment [7]. Due to their lipophilic nature and resistance for biodegradation, PCBs have been bio-accumulated in animal tissues [8], also in domestic animals [9,10]. Therefore PCBs have been also measured in food samples [11] and they can be mentioned as a serious health risk.Since PCBs accumulation in preg...

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Effect of prostaglandins on uterine contractions in the estrous ewe

Rexroad¹,

Barb²

1975

Theriogenology

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Altered motility of myometrium from estrous ewes after the regulation of estrus with progestagen or prostaglandin

Cited by 12 publications

References 10 publications

Sperm Transport into the Cervix of the Ewe after Regulation of Estrus with Prostaglandin or Progestogen

Sperm Transport into the Cervix of the Ewe after Regulation of Estrus with Prostaglandin or Progestogen

The Preliminary Study About the Involvement of Relaxine in Adverse Effect of Polychlorinated Biphenyls on Bovine Myometrial Contractions

Effect of prostaglandins on uterine contractions in the estrous ewe

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