Exposure to benzo(a)pyrene suppresses mitophagy via ANT1-PINK1-Parkin pathway in ovarian corpus luteum during early pregnancy

Abstract Circulating prostaglandin F2α metabolite (PGFM) after an oxytocin challenge was evaluated throughout the first 2 months of pregnancy in lactating Holstein cows. On day 11, 18, and 25 after artificial insemination (AI), and on days 32, 39, 46, 53, and 60 of pregnancy, cows were challenged with 50 IU oxytocin, i.m. Blood was collected before (0 min), 30, 60, 90, and 120 min after oxytocin for plasma PGFM concentrations. Ultrasound evaluations were performed for pregnancy diagnosis on day 32–60 post-AI. Nonpregnant (NP) cows on day 18 were designated by a lack of interferon-stimulated genes in peripheral blood leukocytes and Pregnant (P) based on day 32 ultrasound. On day 11, P and NP were similar with low PGFM and no effect of oxytocin on PGFM. On day 18, oxytocin increased PGFM (3-fold) in NP with little change in P cows. Comparing only P cows from day 11 to 60, basal circulating PGFM increased as pregnancy progressed, with day 11 and 18, lower than all days from day 25 to 60 of pregnancy. Oxytocin-induced PGFM in P cows on day 25 was greater than P cows on day 18 (2.9-fold). However, oxytocin-induced PGFM was lower on day 25 compared to day 53 and 60, with intermediate values on day 32, 39, and 46 of pregnancy. Thus, the corpus luteum (CL) of early pregnancy (day 11, 18) is maintained by suppression of PGF, as reflected by suppressed PGFM in this study. However, during the second month of pregnancy, uterine PGF secretion was not suppressed since basal PGFM and oxytocin-induced PGFM secretion were elevated. Apparently, mechanisms other than suppression of oxytocin receptors maintain CL after day 25 of pregnancy.

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Methotrexate effects on trophoblast and the corpus luteum in early pregnancy

American Journal of Obstetrics and Gynecology ◽

10.1016/s0002-9378(98)70052-3 ◽

1998 ◽

Vol 179 (3) ◽

pp. 604-609 ◽

Cited By ~ 10

Author(s):

Mitchell D. Creinin ◽

Ann M. Stewart-Akers ◽

Julie A. DeLoia

Keyword(s):

Corpus Luteum ◽

Early Pregnancy

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314 EARLY PREGNANCY DIAGNOSIS USING A NOVEL TRANSRECTAL ULTRASONOGRAPHY PROTOCOL IN JAPANESE BLACK COWS

Reproduction Fertility and Development ◽

10.1071/rdv21n1ab314 ◽

2009 ◽

Vol 21 (1) ◽

pp. 254

Author(s):

A. Gaja ◽

C. Kubota ◽

T. Kojima

Keyword(s):

Corpus Luteum ◽

Early Pregnancy ◽

Transrectal Ultrasonography ◽

Blood Collection ◽

Sectional Area ◽

Cross Sectional ◽

Plasma Progesterone ◽

Area Change ◽

Pregnancy Diagnosis ◽

Peripheral Plasma

The present study aims to establish a novel practical protocol for early pregnancy diagnosis in cows by using transrectal ultrasonography. The protocol is based on measurements of corpus luteum (CL) cross-sectional area (CL c-s area) change performed at 2 separate days before the coming estrus after AI. Fourteen cows were inseminated artificially, and transrectal ultrasonographical observation of the ovaries and blood collection for measurement of peripheral plasma progesterone (P4) concentration were carried out daily from Days 12 to 23 (Day 0 = the day of onset of estrus). Thereafter, cows were routinely diagnosed for pregnancy at Day 30 by transrectal ultrasonography. The largest CL c-s area was obtained at Day 14 in both pregnant and non-pregnant cows. Seven out of 8 non-pregnant cows showed significant CL c-s area regression between Days 14 and 20 (422 ± 112 v. 249 ± 63 mm2), whereas no regression was observed between Days 14 and 20 in pregnant cows (416 ± 65 v. 402 ± 78 mm2). The regression in the CL c-s area between pregnant and non-pregnant cows was significantly different during Day 18 (424 ± 65 v. 288 ± 88 mm2) to Day 23 (402 ± 71 v. 139 ± 64 mm2). P4 concentration was significantly low (less than 1 ng mL–1) at Day 20 in 3 out of 8 non-pregnant cows, whereas the pregnant cows showed significant increase of P4 between Days 14 and 20 (2.6 ± 0.2 v. 3.4 ± 0.5 ng mL–1). The pregnant cows showed significantly higher P4 concentration starting from Day 18 than non-pregnant cows. However, in non-pregnant cows, 4 cows returned to estrus on Day 20 or after, 3 cows showed no signs of estrus, and 1 cow came in estrus as early as Day 18 after AI. In conclusion, the results of the present study suggest that measuring the change in the CL c-s area at Days 14 and 20 makes it possible to detect the non-pregnant cows at Day 20 after AI. However, it was also indicated that measuring the change of P4 concentrations on the same days did not always successfully detect non-pregnant cows. The new protocol based on CL c-s area regression rate can detect almost certainly non-pregnant cows at Day 20 after AI. It is suggested that this method is advantageous in research and industrial breeding.

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