ABSTRACT
Stress has different effects on the body and endocrine system. The main aim of this study is to determine the effects of immobilization stress and Aloe vera extract on levels of TSH, T3 or T4 in male rats. In this experimental study, 90 male Wistar rats were randomly divided into 9 groups of control, receiving normal saline, receiving Aloe vera extract, acutely immobilized [8 h/day immobilization for 8 days], chronically immobilized [2 h/day immobilization for 21 days] acutely immobilized receiving Aloe vera extract, chronically immobilized receiving Aloe vera extract, acutely immobilized receiving normal saline and chronically immobilized receiving normal saline [n = 10]. Blood samples were collected using cardiac puncture method and hormone levels were measured by electrochemiluminescence [ECL] method. Data were statistically analyzed and compared among groups using ANOVA. Results showed that levels of T3 and T4 were significantly increased in rats enduring acute immobilization stress compared with animals in control group [P = 0.001]. Serum T3 and T4 were significantly decreased in Aloe vera receiving rats compared with control group [P < 0.05 or P < 0.01, respectively]. Level of T3 was significantly decreased in acutely immobilized rats receiving Aloe vera compared with control group [P = 0.001]. Level of T3 and T4 levels were significantly decreased in chronically immobilized rats receiving Aloe vera compared with control group [P < 0.05]. The findings show that acute immobilization enhances levels of T3, T4 and TSH and the use of Aloe vera extract can prevent this kind of increase
ABSTRACT
Various studies indicate that gonadal hormones exert modulatory effects on pain threshold. The aim of this study was to investigate the role of estradiol or progesterone in the response by female rats to thermal nociceptive stimulation. In this laboratory experimental study, thirty 7 week old albino [Wistar] rats were randomly divided into control, sham and ovariectomised groups of 10 each. After 10, 20 or 40 days thermal pain threshold was measured through tail immersion test [55[degree sign]C water bath]. The pain threshold was measured as the time required eliciting a flick of the tail which was called analgesia time. Serum estradiol, progesterone or prolactin levels were also simultaneously measured by radioimmunoassay method. Data were statistically analyzed and compared between groups using ANOVA. There was no significant change in serum estradiol or progesterone levels as well as analgesia time 10 days after ovariectomy; however, a significant decrease was observed 20 or 40 days after operation compared with control female rats [p<0.001, p<0.05 or p<0.001, respectively]. Also there was no significant change in serum prolactin level 10 or 20 days after ovariectomy compared with control rats; however, a significant decrease was observed 40 days compared with 20 days after ovariectomy [p<0.05]. Our findings clearly indicate that depletion of female gonadal hormones 20 or 40 days after ovariectomy modulates the pain-induced behavioral responses related to thermal nociception in female animals
ABSTRACT
Studies show that smoking can influence endocrinological functions of thyroid gland. The main aim of this study was to determine the effects of cigarette and waterpipe smoke on serum level of TSH, T3 and T4 in male rats. In this laboratory experimental study, male Wistar rats were randomly divided into control, cigarette, and waterpipe smoking animals of 5 in each group. After 6 weeks, blood samples were collected using cardiac puncture method. Following serum collection, levels of TSH, T3 and T4 were measured by radioimmunoassay method. Data were statistically analyzed and compared between groups using ANOVA. The results indicated that serum T3 and T4 levels were significantly increased in cigarette smoking rats compared with control animals [p<0.001 and p<0.01 respectively]. Serum levels of T3 and T4 were also increased in waterpipe smoking rats compared with control animals [p<0.01]. Serum level of TSH was insignificantly decreased in cigarette and increased in waterpipe smoking rats, respectively. Our findings show that cigarette or waterpipe smoking enhances endocrinilogical function of thyroid gland appeared in increased serum level of T3 and T4; therefore, the effects of cigarette and waterpipe smoke on hyperthyroidism induction is important