QUANTITATIVE HISTOCHEMISTRY OF THE NEPHRON. VI. HYDROXYPROLINE IN THE HUMAN GLOMERULUS*

Abstract

The hydroxyproline concentration in glomerular tufts from 9 healthy kidneys was measured, and was found to be 1.109% of the dry weight. Its concentration was not related to the age of the subjects. In renal arcuate arteries the hydroxyproline concentration was 3.88 to 4.88% of dry weight. In abnormal glomeruli from 3 subjects the hydroxyproline concentration was significantly higher than in normal glomeruli, the highest concentration being found in a case of diabetic nephropathy. These findings indicate that collagen is present in the glomerular basement membranes. The absence of fibrils, which has been demonstrated by the electron microscope, suggests that the collagen is present in a form which is a precursor of that with 640 A banded fibrils, possibly neutral salt-extractable collagen.