Effects of maternal caffeine intake on the growth of rat tooth germs in protein-energy malnourished neonates.

Fourteen rat dams with 8 pups each were fed either a 6, 12 or 20 per cent protein diet upon birth. Another group of 12 dams with the same number of pups was pair-fed either a 6, 12 or 20 per cent protein diet supplemented with caffeine (2 mg/100 g body weight). At day 15, randomly-selected pups were injected with [14C]-proline to determine collagen synthesis of the incisor and molar tooth germs. Another group of pups was used to determine calcium content of these tooth germs. Body weight, incisor weight and total calcium contents of tooth germs of pups from dams fed with 6 per cent protein diet were greater in the caffeine-supplemented group, whereas in the 20 per cent protein diet with caffeine group, these parameters were lower. The molar weights of the 12 per cent protein diet with caffeine animals were greater than the 12 per cent group without caffeine. The total hydroxyproline content of the incisor tooth germs from animals in the 12 per cent protein diet with caffeine was greater than is the non-caffeine group. However, total hydroxyproline of the molar tooth germs in the 20 per cent protein groups with caffeine was less than in the non-caffeine group. The rate of collagen synthesis of the incisor and molar tooth germs showed no difference in the presence or absence of caffeine in the 6, 12 and 20 per cent protein groups. Incisor and molar tooth germs are thus affected differently by the interaction of protein and caffeine, possibly due to differences in the pattern of tooth development.

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.

The role of ascorbic acid deficiency in human gingivitis--a new hypothesis.

Periodontal disease is one of the most prevalent health problems in the world and is the major cause of tooth loss in the adult population. Its two major subdivisions are gingivitis where disease is confined to the gingiva, and periodontitis where disease is present both in the gingiva and the supporting periodontal tissues. During the first stage there is a vasculitis of vessels subjacent to the junctional epithelium which is followed by exudation of fluid from the gingival sulcus and migration of leukocytes. There is variable expression of this stage throughout the mouth with new areas of involvement appearing in place of healed areas. Mast cells which are present in the gingival connective tissues may participate in this inflammatory response by liberating histamine. Ascorbic acid deficiency has been shown to be a conditioning factor in the development of gingivitis. When humans are placed on ascorbic acid deficient diets there is increased edema, redness and swelling of the gingiva. These changes have been attributed to deficient collagen production by gingival blood vessels. However, this may be due to an antihistamine role of ascorbic acid. This vitamin may act to directly detoxify histamine or effect a change in the level of enzymes responsible for histamine metabolism. This could occur through the influence of ascorbic acid in altering cyclic AMP (c-AMP) levels. Such changes in the level of this regulatory molecule could result in increased histamine-N-methyl transferase and other enzymes responsible for the breakdown of histamine.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of retinoic acid on the growth of mandible and long bone in fetal rats.

Timed-pregnant rats were injected with a total of 90 microgram of retinoic acid from day 13 until delivery. Other pregnant groups were given either a total of 390 microgram of retinol from day 5 or a total of 270 microgram of retinol from day 13 until delivery. Although the weight gains and food intake of the dams during gestation showed no difference between groups, the long bones were slightly heavier in pups born from retinoic acid-injected dams. Total collagen content in both mandibles and long bones did not show differences between retinoic acid- and retinol-injected groups, but collagen synthesis in both bones was greatly increased in the retinoic acid-injected groups. Calcium content of the mandible in the retinol-injected group from day 13 of gestation was increased, whereas 45Ca uptake of long bone of this group was increased. Retinoic acid, when injected in physiological doses during gestation, may have some effects on the organic phase of bone, long bones being slightly more sensitive to retinoic acid than the mandibles.

Significance of protein-energy malnutrition in dentistry: some suggestions for the profession.

A sound nutritional state is extremely important for the maintenance of healthy oral tissues as well as the body in general. Dentistry is, by nature, related to nutrition and dental practitioners should inform their patients and the public of its importance. For this reason, dentists should have a much broader background in nutrition and food sciences.

The effect of calcitonin in vitro on tooth germs in protein-energy malnourished rats.

The effect of calcitonin on the development of incisor and molar tooth germs was studied in normal and nutritionally deprived newborn rats. Calcitonin affected the calcium uptake of nutritionally deprived molar tooth germs in the early postnatal period; this interaction was not seen in the later postnatal period, however.

In vitro collagen synthesis of tooth germs from newborn rats with protein-energy malnutrition.

Mineralization and matrix formation are closely related processes in the growth and development of both incisor and molar tooth germs. Addition of ascorbic acid does not affect in vitro collagen synthesis of tooth germs from protein-energy malnourished rats.