| Abstract: | An investigation of the relationship of succinic dehydrogenase (SDH) and lactate dehydrogenase (LDH) in the pineal gland of the adult female albino rats was carried out during seven definitive stages of the estrous cycle: Early Estrus (E1), Late Estrus (E2), Metestrus (ME), Early Diestrus (D1), Late Diestrus (D2), Preproestrus (PPE) and Proestrus (PE). Controlled housing conditions were maintained on 7:00 A.M. to 7:00 P.M. light-dark cycle. The animals were necropsied at precise times after the onset of estrus and subsequent stages of the cycle. Comparative histochemical and biochemical analysis revealed the following for SDH activity: E2 greater than E1 greater than D2 greater than D1 greater than PPE greater than PE greater than ME; and for LDH activity: PE greater than E2 greater than ME greater than D1 greater than PPE greater than E1 greater than D2. Interrelationships are postulated between pineal SDH, GOT, GPT, and estrogen concentrations in the rat. |
