Figure 3.

Typical tracings showing the effects of U46619, ANG II, and KCl on the basal IAS tone, before and after BDNF and K252a, in the young and aging groups of rats. The tracing show that BDNF enhances the effects of U46619 and ANG II, which are minimized by the combined use of BDNF and K252a, in both age groups. It is noteworthy that in the aging group, BDNF rescues the agonists’ effects approximately to the young control levels. Conversely, neither BDNF nor BDNF+K252a affect the KCl-induced smooth muscle contractility in any of the age groups. ANG II, angiotensin II; BDNF, brain-derived neurotropic factor; IAS, internal anal sphincter; KCl, potassium chloride; K252a, TrkB inhibitor; U46619, thromboxane A₂ analog