The Role of Dl-Dihydroxy Phenyl Alanine (Dopa) on Plasma Transaminase Level Under Altitude Stress

Abstract

Various conditions of experimental and clinical stress and exercise are followed by a change in the level of transaminases in plasma and tissues. This is also true under various pathological conditions. Andreotti et al.(1) reported a transient increase in serum glutamic-oxalacetic (GOT) and glutamic-pyruvic transaminase (GPT) levels during a boxing match. Lending et al. (2) found that there is no significant effect on plasma GOT levels of puppies when exposed under reduced atmospheric pressure conditions for 3 hr. Bedrak (3) observed that even exposure to heat stress and muscular exercise increased the serum GOT and GPT levels of dogs as compared to the corresponding controls. Nerdrum and Berg (4) reported an increase in serum GOT level 10 min after brief exertion, falling to normal in 45 min. Vanlerenberghe et al. (5) found that rats subjected to hypoxia showed marked increase in serum GOT and GPT levels.In the present investigation, the effect of exposure to simulated altitude conditions on plasma transaminases, non-protein nitrogen (NPN) and total protein percentages have been studied, both with and with out the administration of an antistress drug, DOPA. The aim of the administration of DOPA was to assess its efficacy as an antistress drug. Previously our similar studies (6) with methylamphetamine have shown that the drug, methylamphetamine increases serum glutamic pyruvic transaminase (GPT) and NPN values quite significantly as compared to sea level controls.Materials and methods: 1) Male albino rats weighing approx. 200 g were divided into four groups of eight or more. 2) The drug (DOPA) was given to the animals i.p. at a concentration of 2.0mg/kg body wt., 30 min prior to drawing of blood or subjection to stress. 3) The stress involved enclosing the animals in a vacuum chamber for 3 hr at 350 mm of Hg. After the stress period, the animals were quickly anaesthetized with ether and blood was drawn by cardiac puncture into a bottle containing sodium fluoride. The total time from removal out of the high altitude chamber to the collection of blood was approx. 7 min. 4) Transaminases in blood were estimated colorimetrically according to the method of Reitman and Frankel (7). 5) Non-protein nitrogen (NPN) in blood was estimated by the method of Folin and Wu (8). 6) Total protein was estimated by Micro-Kjeldahl method (9).