Abstract

EFFECT ON BIOCHEMICAL CONSTITUENTS OF GAMBUSIA AFFINIS AT 30°C

Dr. Sabiha Khan*

Abstract

The fish Gambusia affiniswas exposed to sub-lethal concentration of 7x10-3 μg/ l cadmium for 30th days (probit method). Autopsy of liver and kidney was done after 30th days and SDH, GDH, MDH and LDH levels were estimated by using the method of Nachlas et al. (1960), Srikanthan and Krishnamoorthy (1955), Lee and Lardy(1965) and Burns and Bergmeyer (1965) respectively. A decrease in SDH activity levels is due to accumulation of the succinate. Decreased GDH activity in both tissues is an indication of decreased oxidation of glutamate. and may be due to low utilization of amino acids and low oxidation of amino acids. Marked decrease in MDH levels in both tissues might be due to restricted supply of substrate, as observed. Decrease in MDH may be due to diversion of aerobic metabolism at the level of malic acid, leading to the production of pyruvic acid. The elevation in the activity levels of LDH in both tissues indicates an increased production of pyruvate (or) greater breakdown of lactate. and high energy demand for survival in anaerobic conditions and to overcome cadmium stress.

Keywords: Sublethal, SDH, MDH, LDH and GDH.