The Effects of Acute and Chronic Immobilization Stress and Aloe vera Extract on Serum Levels of TSH, T3 and T4 in Male Rats

Abstract

Thyroid gland function is influenced by various types of stress and plant extracts. The aim of this study was to investigate the role of immobilization stress and Aloe vera extract on serum levels of TSH, T3 and T4 in male rats. Male Wistar rats were divided into control, normal saline receiving, Aloe vera extract (300mg/kg/body weight) receiving, acutely immobilized (8h/day for 8 days), chronically immobilized (2h/day for 21 days) and under acutely or chronically immobilized Aloe vera extract receiving groups of 10 in each. Following serum collection, hormone levels were measured by electrochemiluminescence method. Data were compared statistically between groups using ANOVA. Serum level of TSH was not significantly altered in experimental groups compared to control rats. However, serum T3 and T4 levels were significantly increased in acutely immobilized rats compared with control rats (P<0.001, P<0.01 respectively); however, there was no significant difference in serum T3 and T4 levels between chronically immobilized rats and control animals. Serum T3 and T4 levels were significantly decreased in extract receiving and chronically immobilized extract receiving rats compared to control animals (P<0.05, P<0.001, P<0.05, respectively). Serum T3 level was significantly decreased in acutely immobilized extract receiving rats compared to control animals (P<0.001). Serum T3 and T4 levels were significantly lower in chronically immobilized extract receiving rats compared to chronically immobilized animals (P<0.01). Our findings indicate that acute immobilization stress has excitatory effects on thyroid function to enhance serum T3 and T4 level, however, Aloe vera extract administration can withstand against.