EFFECT OF PARTIAL WATER-DEPRIVATION AND RESTRICTED FEEDING ON AGE-RELATED-CHANGES IN 2 ENZYMES OF ENERGY-METABOLISM IN THE BRAIN OF MALE GARDEN LIZARDS

The lactate dehydrogenase (LDH) activity of garden lizard brain did no t change with advancing age. On the other hand the succinate dehydroge nase (SDH) activity showed a decline during maturation (young to middl e-aged) remaining stabilized thereafter. Seven days of partial water d eprivation did not alter the LDH activity of lizards of all three age groups but caused an increase in SDH activity of old lizards only. Res tricted feeding led to a decline in the activities of both the enzymes (LDH and SDH) in young lizards and an increase in LDH activity of onl y the old, the response in middle-aged being insignificant. The protei n content of the brain did not change during maturation, but declined in old lizards. Partial water deprivation caused an increase in protei n content of the brain of both middle-aged and old lizards but not in young counterparts. Only the young lizards showed an increase in prote in content of the brain in response to food restriction.