Abstract

ROLE OF THYROXIN IN IMMUNE MODULATION IN GOATS: AN IN VIVO AND IN VITRO STUDY

Somenath Ghosh*

Abstract

The immune system is coordinated by a number of cytokines which are regarded as chemical messengers of immunity. Some of them are proinflammatory (e.g. IL-2), some are anti-inflammatory (e.g. IL-6), some can be regarded as a switch between pro and anti-inflammatory processes (e.g. TNF-α). Further, immune regulation in body is a proper balance between mitosis and apoptosis occurring simultaneously in the body. In the present paper we explored the spleen and thymus functions by assessing %SR and % apoptotic rate of splenocytes and thymocytes being significantly high levels of cell proliferation (in terms of %SR) and apoptosis rate during monsoon and winter seasons. We noted IL-2 (a pro-inflammatory cytokine), IL-6 (an antiinflammatory cykine), TNF-α (a switch between pro and antiinflammatory cytokine) and IFN-γ (a marker of viral infection) in circulation of goats. We noted significantly high levels of IL-2 and TNF-α levels during monsoon and winter but IFN-γ and IL-6 levels were only high during monsoon. Hence, to ameliorate the elevated inflammatory stress level particularly during monsoon goats have evolved a number of adaptive strategies. But, simultaneously during monsoon the gonadal steroid levels are also high which are reported as immune suppressor. Thus, the basic query may arise how goats are proved to be a better survivor under the season of stress (Particularly during monsoon) when the level of potent immune enhancer neurohormone melatonin level is also low.

Keywords: Goat, Hormone, Immunity, Melatonin, Thyroxin.