Age and sex variations of bone matrix proteins in Wistar rats

Collagen and noncollagenous proteins (NCP) have been studied in Wistar rats according to the age and sex. The total amounts of bone matrix proteins, EDTA extracts and the soluble collagenase resistant fraction (SCRF) decreases with aging while the insoluble collagenase resistant fraction (ICRF) increases. No consistent sex-differences have been observed. In the bone matrix, the sialic acid and hexose contents increase with age, the uronic acid value decreases while hydroxyproline does not change. In the EDTA extracts, the collagen extractability decreases markedly with age, the sialic acid content increases while the hexose and uronic acid contents do not vary. Plasma proteins (albumin, orosomucoid and IgG) also do not change with aging. In the collagenase digests, no age and sex differences were found in the collagen and noncollagenous proteins of the SCRF while in the ICRF a decrease was observed for hexoses, uronic acid and sialic acid and an increase for hydroxyproline from the third month onwards.