ラット精細管および精巣上体管における経上皮性アンドロゲン移行に関する研究

Abstract

微小穿刺法と微小灌流法を用いた。精細管の管内アンドロゲン濃度は間質液中のその濃度が10-2, 000nMに増大するに従い直線的に増大したが, 精巣上体頭部における管内アンドロゲン濃度は間質液中の濃度が増大するに従い双曲線的に増大し, 精細管におけるそれよりもはるかに高い値を示した。灌流液中に0.1nMのジニトロフェノール, 0.1mMのKCN, 100μg/mlのサイクロヘキサミドを加えたとき, 管内アンドロゲンの移行は組織ATP濃度とともに有意に減少した。アンドロゲン結合蛋白を含まない人工的精上体頭部の管内液で管内を灌流したとき濃度勾配に抗したアンドロゲン移行は完全に抑制された

The mechanisms involved in the maintenance of the endocrinological microenvironment of the seminiferous and epididymal tubules were examined in a series of experiments utilizing in vivo microperifusion, microperfusion, and micropuncture technique. The intraluminal 3H-androgen concentration in the seminiferous tubules increased linearly as the interstitial 3H-androgen concentrations increased from 10 nM to 2, 000 nM, but in the caput epididymidal tubules, the intraluminal 3H-androgen concentration increased hyperbolically across the same range of peritubular 3H-androgen concentration. Intraluminal 3H-androgen concentrations in the caput epididymidis did not rise above approximately 340 nM even when the peritubular 3H-androgen concentration exceeded 2, 000 nM. Perifusion of caput tubules with 0.1 mM dinitrophenol or potassium cyanide or 100 micrograms/ml cyclohexamide significantly reduced the proluminal 3H-androgen movement, but tubules perifused with control medium did not support antigrade 3H-androgen movement in the absence of native lumen fluids which contain androgen-binding protein. Energy-requiring protein synthesis is necessary for antigrade 3H-androgen movement in the caput epididymidis, but the mechanism for the interaction of intracellular protein(s) and 3H-androgen movement remains undetermined.