EXPOSURE TO LOUD NOISE ALTERS THE FUNCTION OF HYPOTHALAMUS PITUITARY ADRENAL (HPA) AXIS RESULTING IN DEPRESSED LEVEL OF

HUMORAL IMMUNITY BY SUPPRESSING B-LYMPHOCYTE PROLIFERATION

ABSTRACT

Aims:  Aim of this study was to determine the effects of Diazepam on the rate of proliferation in corticotrophs of adenohypophysis which occurs in response to noise stress. Also the effect of the above mentioned drug on plasma ACTH and serum Corticosterone levels was investigated.

Study Design: Experimental Study

Method: Male Albino rats of Brooklyn strain were used in this experimental study. The animals were divided into Groups A, B and C. Group A served as control, Group B animals got exposed to loud noise of 100 dB 4-6 hrs daily for 30 days while, the animals of Group C had been injected with Diazepam (5mg/kg of body weight) intraperitoneally 30 minutes prior to the induction of noise-stress. At the end of the 30 days animals were decapitated, pituitary glands were dissected out for processing and sectioning and blood samples were collected for hormonal analysis.

Results: The results indicated that prior treatment with Diazepam reduces the rate of cell (Corticotroph) proliferation with in the adenohypophysis to some extent. The results also suggest that pretreatment with Diazepam leads to stress hormones levels much close to the normal levels even during highly stressful conditions.

Conclusion: It has been concluded from the present study that an anxiolytic drug like Diazepam can slow down the rate of proliferation of stress hormone producing cells (corticotrophs) with in the pituitary glands of rats exposed to intense noise-stress for a longer period of time and this drug is also able to lower down the continuously raised cortisol levels in stressful conditions which can be damaging for different body system