Effect of stress on galanin secretion in rats fed different levels of their energy requirement

Aim and Galanin is a potent factor regulating appetite and energy balance. galanin injection to the nucleus involved in food intake، stimulate food intake. On the other hand، negative energy balance is accompanied with epinephrine and cortisol level. In this study was investigated cortisol and epinephrine effect on galanin secretion in rats fed different levels of their energy requirement. 45 male wistar rats (300-350 g، 15 per group) were fed a diet containing 100%، 50% and 25% of their energy requirement for 10 days. Afterwards each rat after 48 h prolonged fasting was anesthetized and then cannulated in the carotid artery for injection and blood sampling. Animals were divided into 3 treatment groups that recived (3 µg/Kg BW) either EN، Cortisol or combination of those tow (0. 1 mg in 1 ml of PBS). Galanin and glucose levels were analyzed before (in time of 0) and 30، 60 and 120 min after injection. in 50% and 100% food restricted group fasting galanin levels fell after EN injection. (p≤0. 05). cortisol just reduced galanin in 50% food restricted group (p≤0. 05). In contrast، the group that has 25% food restriction didn’t show any response to cortisol، EN and combination of EN and cortisol injection (p>0. 05). These results indicate that injection of EN suppress starvation-induced secretion of ghalanin in normal (100%) and starved (50%) rats. And the galanin secretion response to EN might be affected by weight loss as it doesn''t be suppressed in starved (25%) rats.