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This study was conducted to estimate the effects of kisspeptin-10 on blood concentrations of LH and GH in prepubertal dairy heifers. Heifers received a single injection of 1 mg kisspeptin-10 (nZ5) or saline (nZ5) intravenously, and serial blood samples were collected at 15-min intervals to analyze the response curves of both LH and GH after injection. Peakshaped responses were observed for concentrations of LH and GH, and the peaks were observed at 27G3 and 75G9 min, respectively, after injection, only in heifers injected with kisspeptin-10.

Recent studies suggest that IGF-I is a crucial regulatory factor in follicular growth during early post-partum period. The aim of the present study was to determine in detail the changing profiles of metabolic and reproductive hormones in relation to ovulation of the dominant follicle (DF) of the first follicular wave post-partum in high-producing dairy cows. Plasma concentrations of related hormones in 22 multiparous Holstein cows were measured from 4 weeks pre-partum to 3 weeks post-partum, and the development of DF was observed with colour Doppler ultrasound. Thirteen cows showed ovulation by 15.2 days post-partum. Anovulatory cows showed higher GH and lower IGF-I levels than those in ovulatory cows during the peri-partum period. Each DF developed similarly, and a clear blood flow in the follicle wall was observed despite ovulation or anovulation. In addition, detailed endocrine profiles were analyzed in 9 out of the 22 cows. Five cows showed an increase in plasma oestradiol-17b (E2) with follicular growth followed by E2 peak, LH surge and ovulation. In these cows, plasma IGF-I concentrations remained high until 10 days post-partum followed by a gradual decrease. Subsequently, the insulin level increased together with the E2 peak towards ovulation. These profiles were not observed in anovulatory cows. In conclusion, our data strongly support the concept that IGF-I and insulin represent 'metabolic signals' of the resumption of ovarian function post-partum in high-producing dairy cows. Moreover, we provide the first visual evidence that both ovulatory and anovulatory DFs of the first follicular wave post-partum are similarly supplied with active blood flow.

This study aimed to investigate the presence of polymorphonuclear neutrophils (PMNs) in bovine oviduct fluid under physiological conditions and to determine the possible role of bovine oviduct epithelial cells (BOECs) in the regulation of the phagocytic activity of PMNs for sperm. During the pre-ovulatory stage, PMNs were identified in the bovine oviduct fluid in relatively constant numbers. In our experiments, PMNs were incubated for 4 h with the supernatant of cultured BOECs stimulated for 24 h by LH (10 ng/ml). Phagocytosis was then assayed by co-incubation of these PMNs with sperm treated to induce capacitation. The BOEC supernatant significantly suppressed sperm phagocytosis by PMNs, and the LH-stimulated BOEC supernatant further suppressed phagocytosis. Importantly, in the BOEC culture, LH stimulated the secretion of prostaglandin E 2 (PGE 2 ), which dose-dependently (10 K6 , 10 K7 , and 10 K8 M) suppressed sperm phagocytosis by PMNs. Furthermore, a PGEP 2 receptor antagonist significantly abrogated the inhibition of phagocytosis by the LH-stimulated BOEC supernatant. Additionally, using scanning electron microscopy, incubation of PMNs with either PGE 2 or LH-stimulated BOEC supernatant before phagocytosis was found to prevent the formation of DNA-based neutrophil extracellular traps for sperm entanglement. The results indicate that sperm are exposed to PMNs in the oviduct and PGE 2 released into the oviduct fluid after LH stimulation may play a major role in the suppression of the phagocytic activity of PMNs for sperm via interaction with EP 2 receptors. Thus, the bovine oviduct provides a PGE 2 -rich microenvironment to protect sperm from phagocytosis by PMNs, thereby supporting sperm survival in the oviduct.Free Japanese abstract A Japanese translation of this abstract is freely available at

Abstract. The cryopreservation of ovarian tissues is a technology with significant potential for the preservation of the genetic resource materials of working dogs, including guide dogs for the blind. However, no attempt has been reported on cryopreservation of the canine ovary. Thus, we evaluated a vitrification method for cryopreservation of canine ovaries and determined the potential functionality of vitrified-warmed canine ovaries by means of transplantation into non-obese diabeticsevere combined immunodeficiency (NOD-SCID) mice. All ovarian tissues cryopreserved by vitrification were morphologically normal in terms of histology. Cryopreserved ovaries were transplanted into the ovarian bursa of the NOD-SCID mice, and the xenografts were recovered from 23 of 23 mice (100%) 4 weeks after the operation. The transplanted canine tissue was tightly adhered to the mouse ovary. Although antral follicle formation did not occur after grafting, proliferating cell nuclear antigen immunoreactivity was detectable in many of the granulosa cells in the primary follicles of the grafts. These results indicate that cryopreservation of the canine ovary by vitrification appears to have the potential to restore endocrine function and ovulation potential.

Abstract. In cows, interferon-tau (IFNT) regulates maternal recognition around days 15-19 after artificial insemination (AI). The present study hypothesized that if key target genes of IFNT are clearly upregulated in earlier stages of pregnancy, these genes could be use as indices of future pregnancy in cows. Therefore, we determined the expression of these genes in peripheral blood mononuclear leukocytes (PBMCs) and polymorphonuclear granulocytes (PMNs) during the maternal recognition period (MRP). Twenty multiparous Holstein cows were subjected to AI on day 0 and categorized into the following groups: pregnancy (Preg, n = 9), embryonic death (ED, n = 5) and non-pregnancy (NP, n = 6). Progesterone levels in the Preg group were higher than those in the NP group on days 12-21. ISG15 and OAS-1 (IFN-stimulated genes: ISGs) mRNA in PBMCs on day 8 was higher in the Preg group than in the NP group, and these mRNAs in PMNs was higher in the Preg group on day 5 than in the NP and ED groups. Interleukin-10 (IL-10, Th2 cytokine) mRNA expression increased on day 8 in the PBMCs of pregnant cows. Tumor necrosis factor α (TNFα, Th1 cytokine) mRNA expression was stable in all groups. In an in vitro cell culture experiment, IFNT stimulated mRNA expression of ISGs in both PBMCs and PMNs. IFNT stimulated IL-10 mRNA expression in PBMCs, whereas IFNT increased TNFα mRNA levels in PBMCs in vitro. The results suggest that ISGs and IL-10 could be responsive to IFNT before the MRP in peripheral blood immune cells and may be useful target genes for reliable indices of pregnancy before the MRP. Key words: Cow, Immune cells, Interferon tau, Pregnancy (J. Reprod. Dev. 58: [84][85][86][87][88][89][90] 2012) D uring the past 5 decades, milk production per cow has dramatically increased because of improved management, nutrition, and genetic selection [1,2]. In contrast, the decreases in fertility and conception rates of the modern high-producing dairy cow are the major causes of economic loss for dairy producers [2,3]. After establishment of pregnancy in domestic ruminants, the conceptus secretes interferon-tau (IFNT) as a maternal recognition factor [4]. IFNT acts in the uterus around day 16 after insemination and prevents luteolysis by inhibiting prostaglandin F 2α release, resulting in the maintenance of corpus luteum function; therefore, this period is termed the maternal recognition period (MRP) [5]. IFNT induces the synthesis and secretion of IFN-stimulated genes (ISGs) such as ISG15, 2′,5′-oligoadenylate synthetase (OAS-1), IFN regulatory factor 1, Mx1 and Mx2 not only in the uterus but also in blood cells in ewes and cows [6][7][8][9][10]. In fact, in bovine peripheral blood leukocytes, ISG15 mRNA levels were higher in pregnant cows than in nonpregnant cows on days 18 and 20 after artificial insemination (AI) [7][8][9]. Technology for the early detection of pregnancy is needed to identify nonpregnant cows and to synchronize and artificially inseminate these cows prior to the next ovulation, and many studies have focused on identify...

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