Abstract:  

Neurotrophins are well-known growth factors which can play integral roles in the control and regulation of the gastrointestinal tract (GIT). The anabolic steroid testoster?one is involved in altering the contractile function of the stom?ach and intestine. The interactions between neurotrophin fac?tors and testosterone are strong in many systems such as the nervous and respiratory systems. However, these interactions are not clearly determined in the gastrointestinal tract. The aim of this study is to investigate the effect of the anabolic steroid sustanon on the expression levels of neurotrophins in the chicken GIT. Neurotrophins? ELISA was done on normalized total protein extracts from the stomach, intestine, and colon, and the results were compared between control and sustanon?treated groups. BDNF, NGF, NT-3, and NT-4 are present at different levels in the entire wall of the chicken GIT. Sustanon increased BDNF levels in the stomach and intestine in dose?dependent manner and had no effect in the colon. Sustanon had no effect on NGF in the stomach and intestine; however, at high doses, it increased NGF levels in the colon. High dose of sustanon increased the levels of NT-3 in all regions of the chicken GIT. The effect on NT-4 was obviously region spe?cific, where sustanon had an inhibiting effect in the stomach, augmenting effect in the intestine, and no effect in the colon. These results indicate that the anabolic steroid sustanon has differential effects on neurotrophins? levels in the chicken GIT and this effect might explain the GIT symptoms associated with the use of these steroids.