Maxillary and dental development in the offspring of protein-restricted female rats.

Nutritional restriction during developmental periods impairs organ physiology. Female rats were subjected to protein restriction during pregnancy and lactation to analyze dental and maxillary development. Four exposure groups were considered: normal-protein diet during pregnancy and lactation (NP, 17% casein), low-protein diet during lactation (LP-L, 6% casein), low-protein diet during pregnancy and lactation (LP), and low-protein diet during pregnancy (LP-G). Maxillae from 15-day-old male pups were collected. All protein-restricted groups presented increased dentin thickness and reduced alveolar bone area. When protein restriction was applied during both gestation and lactation (LP), harmful effects were observed in the form of loss of protective OPG (osteoprotegerin) in tooth epithelium-mesenchyme, due to higher RANKL expression, delay in odontoblast maturation, less dental pulp vascularity, reduction in amount of alveolar bone, and less matrix mineralization. In the LP-L group, effects of protein restriction seemed less harmful, and despite less alveolar bone, the enhancement in BMP-7, VEGF, and RANKL seems a compensatory signal to maintain maxillary osteogenesis. In LP-G animals, Dspp expression was higher, suggesting a delay in odontoblast maturation or expression recuperation. In conclusion, maternal protein restriction affects dental and maxillary development. A low-protein diet only in gestation allows for normal development. A low-protein diet during gestation-lactation results in impaired odontogenesis that may increase susceptibility of dental anomalies.

Morphofunctional and immunological cardiac evaluation of protein restriction on rat offspring.

Cardiovascular diseases affect a large part of the population during adulthood. Several epidemiological and experimental studies have demonstrated an association between maternal protein restriction and a marked risk of developing heart disease during early intrauterine and postnatal life. Maternal nutritional conditions act by modulating the microenvironment, thus favoring adaptive processes of the fetal organism for development to occur. However, the physiological profile is established in this period and its effects can be observed in the long term. In the present study, the cardiac muscles of 15-day-old offspring of Wistar rats subjected to maternal protein restriction during pregnancy and/or lactation were evaluated to identify possible cardiac changes relevant for heart disease in adulthood. The offspring of restricted female rats during pregnancy had a lower birth weight. Male offspring subjected to restriction during pregnancy and lactation showed an increase in the concentration of H2O2, a reduction in the expression of the Mn-SOD enzyme, and a greater expression of ß-MHC and Connexin 43. There was also an increase in the MPO enzyme activity in the tissue. It was observed that the effects of protein restriction are sex-specific, since the cardiac muscle of male animals showed alterations suggestive of oxidative stress, hypertrophy, signs of tissue inflammation, and increased expression of important proteins in intercellular communication. These changes characterize the ongoing cardiac remodeling process. Finally, the data revealed that the lactation phase accentuated harmful effects on the cardiac tissue of the offspring.

Gestational protein restriction alters the RANKL/OPG system in the dental germ of offsprings.

Evaluate the dentinogenesis in the offspring of rats submitted to gestational protein restriction (GPR). DESIGN: The offspring were evaluated at the 21st day of gestation (21 dG). Assessments were made of morphological parameters and the RANKL/OPG system - bone tissue maturation markers - in the upper incisor tooth germ. Pregnant 10-week-old female Wistar rats were divided into normal protein (NP, 17% casein, n = 5) and low protein (LP, 6% casein, n = 5) diet groups. At 21 dG, the offspring maxillae were collected for histomorphometric and immunohistochemical analyses. RESULTS: The LP group showed decreased thickness of the dentin and odontoblast cell layers on the tooth germ. GPR led to decreased OPG expression and increased RANKL expression in the incisor germ. CONCLUSION: The results suggested that gestational protein restriction altered odontoblast RANKL/OPG expression and decreased dentin matrix deposition and thickness in tooth development.