Abstract
Using an EDTA extraction procedure, bones from pregnant Wistar rats were analyzed for their content of collagen and non-collagenous components (sialoprotein, proteoglycan and carbohydrate). The bone matrix size was found to be smaller in pregnant rats than in normal rats (19·5% vs 17·5% of the dry weight bone). The EDTA extractability of the bone protein from pregnant rats was higher than that from controls (2·6% vs 1·9% dry weight bone). EDTA extracts from pregnant rats contained higher amounts of soluble collagen (1·6% vs 0·5% of dry weight tissue) and lower amounts of non-collagenous components (1·65% vs 2·23% for hexoses, 2·38% vs 3·95% for sialic acid and 1·24% vs 1·73% for uronic acid). In bone matrix, collagen content was lower in the pregnant rats (9·45% vs 10·6%). Similarly, the amounts of non-collagenous components were slightly decreased in the bone matrix from the pregnant rats. The respective values were: 0·91% vs 0·93% for hexoses, 0·45% vs 0·52% for sialic acid and 0·39% vs 0·50% for uronic acid. These results suggest that in pregnancy collagen and non-collagenous protein content in bone is decreased while the total mineral content is increased.