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| Registros recuperados: 26 | |
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| KAWASHIMA, Chiho; KIDA, Katsuya; MATSUHASHI, Miki; MATSUI, Motozumi; SHIMIZU, Takashi; MATSUNAGA, Nobuyoshi; ISHII, Mitsuo; MIYAKE, Yoh-Ichi; MIYAMOTO, Akio; 川島, 千帆; 木田, 克弥; 松井, 基純; 清水, 隆; 石井, 三都夫; 三宅, 陽一; 宮本, 明夫; 松長, 延吉. |
| The aim of our study was to investigate the effects of suckling on reproductive performance and metabolic status of obese (mean body condition score of more than 4.0 on a scale of 1-5) maternal Japanese Black cows during early postpartum period. We used 7 postpartum Japanese Black cattle. Four cows were suckled ad libitum (suckled) until completion of their first artificial insemination (AI), while 3 cows were not suckled at all because they were separated from their calves immediately after parturition (non-suckled). Body weight and plasma concentrations of metabolites and hormones were measured from wk 1 to 9 postpartum. Ovarian activity was detected using plasma progesterone concentration, and all cows received their first AI after application of the... |
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Palavras-chave: Japanese Black cattle; Metabolic status; Obesity; Reproductive performance; Suckling. |
| Ano: 2008 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2991 |
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| SHIRASUNA, Koumei; WATANABE, Sho; NAGAI, Kaya; SASAHARA, Kiemi; SHIMIZU, Takashi; RICKEN, Albert M.; SPANEL-BOROWSKI, Katharina; MIYAMOTO, Akio; 白砂, 孔明; 清水, 隆; 宮本, 明夫. |
| Cell-to-cell interaction via cell contact-dependent pathway is essentially important for maintenance and regulation of corpus luteum (CL) integrity and its physiological actions. The objective of the present study was to evaluate the mRNA expression of the cell adhesion molecules (CAMs) that are constituent factors of gap junctions [connexin (Cx) 43] and adherence junctions (VE-, E-, N-cadherin) in two types of endothelial cells from the mid CL and in CL tissue during the estrous cycle and PGF2α-induced luteolysis in the cow. Specific mRNA expression for Cx43 and N-cadherin was detected in cytokeratin-positive (CK+) and cytokeratin-negative (CK-) luteal endothelial cells (EC) and fully luteinized granulosa cells (LGC). E-cadherin mRNA was expressed in... |
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Palavras-chave: Cadherin; Connexin; Corpus luteum; Cow; Luteolysis. |
| Ano: 2007 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2988 |
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| SHIRASUNA, Koumei; ASAHI, Takayuki; SASAKI, Motoki; SHIMIZU, Takashi; MIYAMOTO, Akio; 白砂, 孔明; 佐々木, 基樹; 清水, 隆; 宮本, 明夫. |
| We have shown that luteal blood flow increases in the peripheral vasculature of the mature corpus luteum (CL) prior to the onset of luteolysis in response to prostaglandin F2α (PGF2α) in the cow, but this phenomenon does not occur in the early CL. We therefore hypothesize that this acute increase of luteal blood flow occurs by vasodilation of large blood vessels due to local release of nitric oxide (NO). In the present study, we characterized the CL vasculature together with endothelial NO synthase (eNOS) expression during the estrous cycle in the cow. Immunohistochemistry was used to quantify the number of arteriolovenous vessels (surrounded with smooth muscle actin-positive smooth muscle cells), capillaries (with von Willebrand Factor-positive... |
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Palavras-chave: Blood vessels; Corpus luteum; ENOS; Luteolysis. |
| Ano: 2010 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2989 |
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| MAGATA, Fumie; SHIRASUNA, Koumei; STRÜVE, Klaas; HERZOG, Kathrin; SHIMIZU, Takashi; BOLLWEIN, Heinrich; MIYAMOTO, Akio; 清水, 隆; 宮本, 明夫. |
| Persistence of the corpus luteum (CL) in cattle usually occurs during the puerperium and is associated with interference of prostaglandin (PG) F2α release from the uterus. The objective of the present study was to determine for the first time the gene expressions in the persistent CL compared with the CL of pregnancy and cyclic CL. Three types of CL biopsy samples were collected from 32 lactating Holstein cows: (1) CL persisting for 29 to 33 days after the first ovulation postpartum (persistent CL, n=9), (2) CL between days 29 and 33 of early pregnancy (CL of pregnancy, n=8) and (3) CL between days 10 and 13 of the estrous cycle (cyclic CL, n=27). mRNA expression of 2',5'-oligoadenylate synthetase-1 was upregulated only in the CL of pregnancy, confirming... |
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Palavras-chave: Dairy cow; Early pregnancy; Persistent corpus luteum; MRNA expression. |
| Ano: 2012 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4039 |
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| KAWASHIMA, Chiho; MATSUI, Motozumi; SHIMIZU, Takashi; KIDA, Katsuya; MIYAMOTO, Akio; 川島, 千帆; 松井, 基純; 清水, 隆; 木田, 克弥; 宮本, 明夫. |
| During recent decades, milk production per cow has increased drastically due to improved management, nutrition, and genetic selection; however, the reproductive performance of high-producing dairy cows has been declining. One of the factors responsible for this low reproductive performance is negative energy balance (NEB). NEB affects the onset of first ovulation in early postpartum cows. It is generally accepted that early first ovulation positively relates to the resumption of normal ovarian function, first service, and conception rate in dairy cows. Hence, delayed first ovulation has a negative impact on subsequent fertility. The metabolic condition of cows in NEB shifts to catabolic metabolism, which in turn causes increased plasma growth hormone and... |
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Palavras-chave: Β-Carotene; Dairy cow; First follicular wave postpartum; First ovulation; Metabolic hormone. |
| Ano: 2012 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4041 |
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| Registros recuperados: 26 | |
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