Differential effects of collagen in oral tissues and skin by protein-energy malnourished newborn rats and lactating dams.

Effects of protein-energy malnutrition were studied in newborn rats and their dams. Upon delivery, dams received 6%, 12% or 20% protein diets. At Day 15 pups received 14C(U)-proline. The posterior tongue, hard palatal mucosa, soft palatal mucosa and skin were analyzed for collagen and counts incorporated (collagen synthesis, that is, the rate of 14C-proline converted to 14C-hydroxy-proline into gingival collagen). These regions of the dams were also removed to study collagen content. Although soft palatal mucosal collagen of newborns in the 6% and 12% protein groups was decreased, that of skin in the 6% protein group was increased. No such differences were observed in tongue and hard palatal mucosa. Counts incorporated was decreased in the tongue, soft palatal mucosa and skin, but not in hard palatal mucosa. Collagen contents of tongue and hard palatal mucosa and skin of the dams showed no differences, whereas that of soft palatal mucosa in the 6% protein groups was increased. Effects of protein-energy malnutrition on oral tissues and skin were therefore different between newborns and lactating dams. Furthermore, one part of oral mucosa is affected differently from other parts of mucosa and in both, degree of malnutrition has different influences.