Comparative Activities of Growth Hormone and Luteinizing Hormone in the Direct Stimulation of Local Release of Progesterone from Microdialyzed Ovine Corpora Lutea In Vivo
スポンサーリンク
概要
- 論文の詳細を見る
To assess the direct effects of growth hormone (GH) on the release of progesterone (P) in the microenvironment within the ovine corpus luteum (CL) in vivo, a microdialysis system (MDS) was implanted into the CL during the breeding season. In experiment 1 (single CL model), on Day 7 after estrus, three microcapillary dialysis membranes (cut off Mr=1000 kDa; transfer rate, 1% for P and 0.1% for LH and GH) were surgically implanted into the cyclic CL paralleled to each other with a distance of at least a 5 mm between capillaries (n=5 ewes). Each MDS line was continuously perfused with Ringers solution during the experiment. Serial fractions were collected every 30 min for 35 h on Days 8-9 following a pre-perfusion period of 10-12 h. A 16-h perfusion with GH (10 μg/ml) induced an acute increase of P release to 300% of the baseline throughout the infusion (P<0.001). A 3-h perfusion with oxytocin (OT: 2 × 10-5 M) also stimulated the P release to approximately 200% of the baseline (P<0.01). When OT was infused following the GH infusion, no additional effect was observed. In experiment 2 (a multiple CL model), four ewes were treated for superovulation, and multiple CLs formed thereafter were implanted with the MDS (1 line/CL) on Day 7 after GnRH injection. Infusions with GH or LH on Days 9-10 at doses of 2.5, 5 or 10 μg/ml for 4 h twice with an 8-h interval similarly induced a clear increase of P release. The 2nd GH infusion had a greater stimulative effect than the 2nd LH infusion at all the doses tested (P<0.05). Furthermore, the 2nd infusion with GH at 5 and 10 μg/ml induced a higher increase of P release than did the 1st infusion (P<0.05), while LH, at any of the tested doses, stimulated P release to a similar extent during the 1st and 2nd infusions. The finding that GH, like LH, directly stimulates the local release of P within the CL in cyclic and superovulated ewes in vivo strongly suggest that GH, like LH, is an essential luteotropic pituitary hormone in ewes.
- 日本繁殖生物学会の論文
著者
-
Miyamoto Akio
Graduate School Of Animal And Food Hygiene Obihiro University Of Agriculture And Veterinary Medicine
-
FUKUI Yutaka
Department of Food Production Science, Obihiro University of Agriculture and Veterinary Medicine
-
MIYAMOTO Akio
Department of Agricultural and Life Science, Obihiro University of Agriculture and Veterinary Medici
-
Acosta Tomas
Department of Animal Science, Obihiro University of Agriculture and Veterinary Medicine
-
Takemoto Ken-ichi
Department of Animal Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080
-
OHTANI Masayuki
University Farm, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080, Japan
-
YAMADA Junzou
Department of Veterinary Anatomy, Obihiro University of Agriculture and Veterinary Medicine, Obihiro
関連論文
- Gene Expression of 11β-HSD and Glucocorticoid Receptor in the Bovine (Bos taurus) Follicle During Follicular Maturation and Atresia: The Role of Follicular Stimulating Hormone
- Classification of Bovine Follicles Based on the Concentrations of Steroids, Glucose and Lactate in Follicular Fluid and the Status of Accompanying Follicles
- Vascular Changes in the Corpus Luteum During Early Pregnancy in the Cow
- Prostaglandin F_ Differentially Affects mRNA Expression Relating to Angiogenesis, Vasoactivation and Prostaglandins in the Early and Mid Corpus Luteum in the Cow
- eCG/hCG処理した未成熟雌マウスの卵巣におけるPin1(ペプチジルプロピルイソメラーゼ)の発現
- Effects of Seasonal Changes on In Vitro Developmental Competence of Porcine Oocytes
- 北西太平洋において捕獲されたミンククジラおよびニタリクジラの血清中の性ホルモン濃度と精細管組織像との関連性について
- 未成熟クロミンククジラにおける卵巣の発達
- Basal Levels and GnRH-induced Responses of Peripheral Testosterone and Estrogen in Holstein Bulls with Poor Semen Quality
- ウシ生体を用いた黄体形成期における黄体内のプロスタグランジン(PG)F2αおよびPGE2濃度の経時的変化