[Stress caused by immobilization and low protein intake in rats. Morphological changes]

The periodic immobilization of the animals receiving a control diet resulted in a smaller weight gain than in controls. The animals fed a protein deficient diet gained also less weight as compared to controls. The association of the deficiency and the stress of immobilization further decreases the weight gain, but the differences were not significant. The animals submitted to restraint or protein deficiency stress showed an increase in their heart weight in relation to body weight. This increase in more significant when immobilization and protein deficiency were associated. The degree of cardiac muscle fibers damage was also found more pronounced in this group of animals, when analysed through histochemical methods. Liver weight was not found different in the animals submitted to the experimental program. Histological examination of this organ showed fatty infiltration in the protein deficient animals. The picture was not found to be agravated when the animals were further stimulated by the restraint mechanism. Spleen weight was found to be similar in all groups. Histological study of the protein deficient group showed small lesions, that were increased when the deficiency was associated to immobilization. The relative testis weight of the restraint animals receiving the control diet was found to be similar to the animals not immobilized. The protein deficient animals have significantly smaller testis weight than the well nourished group. The histologic study showed that restraint or protein deficiency are responsible for a sexually retarded animal, but the lesions increased with the association of restraint and deficiency.