Protein absorption by tubular mesonephric and metanephric structures in the human embryo. An immunohistochemical study.

The presence of different serum proteins in the cells of the proximal tubule of both meso- and metanephric nephrons in human embryos (7th-12th week of intrauterine life) was investigated using immunohistochemistry. Endogenous lysozyme, alpha-1-antitrypsin and ferritin were detected in mesonephric proximal tubules and, starting from the 8th week, also in metanephric proximal tubules. Our observations provide information concerning the appearance and distribution of tubular protein reabsorption during the early stages of development.