Experimental protein malnutrition in primates: cytochemical studies on the cerebellum of the squirrel monkey, Saimiri sciureus

Effect of Lithium on Rat Cerebrum Under Different Dietary Protein Regimens

This study was designed to investigate the effects of lithium in adult rat brain under different dietary protein regimens. Lithium as carbonate was given at a dose of 1.1 g/kg diet to female rats fed normal (18% protein), low protein (8% protein), and high protein (30% protein) diets for 30 days. Lithium treatment resulted in a significant decrease in the levels of norepinephrine, dopamine, and serotonin in the cerebrum of the rat brain. Further, administration of lithium to rats fed low protein (LP) and high protein (HP) diets also showed a significant decrease in the levels of norepinephrine and dopamine but caused no significant change in the serotonin concentration. Lithium administration to normal diet, LP, and HP groups resulted in a significant increase in the activities of acetylcholinesterase and monoamine oxidase. Lithium treatment led to decrease in the activity of enzyme Na+ K+ ATPase in all groups. On the second day, the LP group showed enhanced transfer latency (TL), a dependent variable to study elevated plus-maze test, whereas HP diet went from 34% reduction to normal. On the other hand, lithium administration restored the already enhanced TL in the LP group. The study concludes that lithium treatment to protein-deficient cases may not further aggravate the effects of protein-deficient conditions, but it may afford protection.

Postnatal vascular growth in the cerebellar cortex of normal and protein-deprived rats. Morphometric studies

The postnatal vascular growth in the cortex of vermis cerebelli folium IX of normal and pre- and postnatally protein-deprived rats was examined. The rate of increase in specific length of vessels seem to parallel the functional maturation of neurons in all cortical layers. From the first postnatal week there is a higher specific length of vessels in the Purkinje cell layer than in the adjoining parts of the molecular and granular layers. The results indicate that such differences are present also after the period of rapid vascular growth. Protein deprivation appears to affect the postnatal increase in specific length of vessels less in the Purkinje cell layer than in the granular and molecular layer where a significant reduction compared to controls was seen for the interval 7--20 days of age. At 90 days of age no significant differences were seen between control and protein-deprived rats.

Cytochemical response of kidney, liver and nervous system of fluoride ions in drinking water

Morphological and cytochemical studies on the squirrel monkey have been made after maintaining the sujects on pure distilled water and fluoridated distilled water for 18 months with the objective of determining the effect of fluoride on the activity of some hydrolytic and oxidative enzymes in the kidney, liver and nervous system. Daily water intake by individual animals was measured over the final 10 months of the animal's exposure to 0,1 and 5 ppm fluoride. Water consumption was considerably higher in the animals on higher fluoride intake. Whereas the nervous system remained totally unaffected by this experimental procedure, the liver showed a slightly enhanced acivity of Krebs citric acid cycle enzymes. The kidneys, however, showed significant cytochemical changes, especially in the animals on 5 ppm fluoride intake in their drinking water. In these animals, the glomeruli showed an increase in the activity of acid phosphatase and the enzymes belonging to the citric acid cycle and the pentose shunt, whereas lactate dehydrogenase, a resentative of the anaerobic glyoclytic pathway, remained unchanged or only slightly changed. These observations suggest that fluoride in concentrations as low as 5 ppm interferes to some extent with the intracellular metabolism of the excretory system.