Effects of unilateral ischemia on the contractile response of the bladder:Protective effect of Tadenan (Pygeum africanum extract)

Recent studies indicate that localized (regional) ischemia may play an impo rtant role in the etiology of the contractile dysfunctions secondary to par tial outlet obstruction, Pretreatment with Tadenan(R) (Pygeum africanum ext ract) has been shown to protect the rabbit bladder against the development of both contractile and biochemical dysfunctions induced by partial outlet obstruction, possibly by protecting the bladder against ischemic injury. Th e current study was designed to determine if Tadenan pretreatment of rabbit s protected the bladder against the development of contractile dysfunctions induced by unilateral ischemia and to correlate effects in the presence an d absence of Tadenan with the molecular response in relation to two of the most prominent genes activated by both ischemia and partial outlet obstruct ion: Hsp-70 and c-myc, Male New Zealand rabbits were separated into four gr oups of six rabbits each. Three rabbits of each group were treated for 3 we eks with Tadenan, The other three rabbits of each group were untreated cont rols, Each rabbit in Groups 2, 3, and 4 was anesthetized, and all major art eries entering on the right side of the bladder were ligated. Rabbits in Gr oup 1 were nonischemic. After 30, 60, and 120 minutes of unilateral ischemi a, the rabbits in groups 2, 3, and 4, respectively, were euthanized, The bl adders were removed, and contractility studies were performed on strips of detrusor muscle isolated from both the ischemia and nonischemic sides. The balance of the ischemic and nonischemic sides were frozen and stored in liq uid nitrogen until analyzed for the expression of Hsp-70 and for c-myc, Tad enan pretreatment protected the nonischemic side of the bladder from the de velopment of contractile dysfunctions, and unilateral ischemia resulted in a 10-fold increase in the expression of both Hsp-70 and c-myc in the bladde rs isolated from the Tadenan-treated rabbits. These results indicate that T adenan has a protective effect against ischemic damage to the bladder. This protection may involve enhanced expression of Hsp-70 and other genetic fac tors.