In Vivo Studies on the Vascular Function in the Bovine Ovary: Determination of Blood Flow and Hormonal Secretion in the Follicle and Corpus Luteum

A transpectal color Doppler ultrasonography was used to assess changes in the ovarian structures and to determine blood flow that tale place in the follicle wall and within the corpus luteum (CL) dring specific physiological events such as ovulation, CL development, and CL regression in cows. To investigate the local release of vasoactive peptides, steroid hormones, and prostaglandins (PGs) in each ovarian structure, the capillary membranes (0.2mm diameter and 5-10mm length) of a microdialysis system (MDS) were implanted surgically implanted into the follicle wall or within the CL along with ovarian venous and jugular catheters to collect simultaneous, real-time information on the ovarian and systemic change in the secretion of factors regulating vascular function. Based on the results obtained from in vivo experiments, it was proposed that a physiological relevant "cross-talk" between the vascular components (endothelial cells) and steroidogenic cells occur in the bovine ovary particularly during ovulation, CL formation and regression.

カラードップラー超音波断層診断装置は，直腸を介して卵巣内の構造変化および血流変化を評価することができ，排卵，黄体形成，黄体退行などの卵巣生理現象の観察に有効である．私は，ウシにおいてカラードップラー超音波断層診断装置を用いて卵胞壁および黄体内の血流変化について検討するとともに，微透析システム（MDS；microdialysis system）を卵胞壁および黄体内に装着し，局所的な血管作動性物質，ステロイドホルモンおよびプロスタグランディン類の分泌を調べた．また，卵巣静脈および頚静脈より血液を経時的に採取し，血管機能を調節する因子の経時的変化についても検討した．これらの成果から，ウシの卵巣生理現象（特に，排卵，黄体形成，および黄体退行）において，卵巣内の血管内皮細胞とステロイド産生細胞（卵胞内膜細胞，顆粒層細胞および黄体細胞）間にクロストーク（相互調節作用）の存在することが示唆された．