Luminal Fluid Proteins of the Male Rat Reproductive Tract

Abstract
Micropuncture samples from rat testis and epididymis were subjected to protein analysis, microelectrophoresis and ABP [androgen binding protein] determinations. Rete testis fluid [RTF] contained only 5% of the total protein concentration of blood serum. Other reproductive tract fluids contained 1/3 to 1/2 the total protein concentrations of blood. Electrophoresis of intratubular fluids from the various testicular and epididymal zones allowed separation of reproductive tract-specific protein bands in each fluid studied. Luminal fluids from the epididymal tubule contained several proteins not appearing in blood. Analysis for androgen binding activity revealed higher concentrations in RTF than in seminiferous tubule fluid. Caput epididymal fluid contained the highest ABP concentration.