BDNF and colitis: However, in rats with high estrogen at the time of testing (proestrus), experimental colitis caused a significant up-regulation of BDNF colonic content from 26.1±8.5 pg/ml to 83.4±32.5 pg/ml (3.2-fold increase, Fig. 4A,N = 7, p≤0.05 to respective control).