European Journal of Biomedical and Pharmaceutical Sciences

DIFFERENTIAL ENDOCRINE RESPONSES OF ANIMALS TO COLD-HYPOXIA- RESTRAIN STRESS

Dishari Ghosh*, Geetha Suryakumar and Karan Pal

ABSTRACT

There are large and enduring differences between individuals in the magnitude of their response to stress. The aim of the present study is to differentiate the animals exposed to simulated cold and hypoxia in a restrain condition (C-H-R) and to evaluate the hormonal profile responsible for individual variation in response to the stress. Time taken to attain the rectal temperature (Trec) of 23oC was measured after exposing the animals to Cold (5OC), Hypoxia (428 mmHg) Restrain (C-H-R) stress and screened with reference to their timing to attain Trec 23OC and segregate them as susceptible, normal and resistant. The hormonal profiles of these animals were evaluated after exposure to the test. The study showed a distinct individual difference in response to C-H-R test. There was a significant increase in plasma norepinephrine concentration (p<0.05) in resistant group than susceptible rats. Total circulating corticosterone (CORT) level also increased but this was not significant between those two groups. Corticosteroid binding globulin (CBG) concentration differ significantly (p<0.05) between resistant and susceptible groups of rats resulting in significant changes in circulating free CORT that in turn may be responsible for individual differences in stress response. Present study showed that multiple components rather than only plasma glucocorticoid are responsible for individual differences in physiological responses to stress. The results also indicate that these endocrine parameters can serve as biomarkers for screening individuals for resistance/susceptibility to high altitude stress.

Keywords: C-H-R stress, catecholamine, corticosterone, ACTH, CBG.