The Effects Of Rhynchophylline On Relaxation And Contraction Of The Bladder Detrusor In Rats

ObjectiveObserve the effect of Rhynchophylline on the relaxation and contraction of rat bladder detrusor and urodynamics, changes in the tension of isolated rat bladder muscle strips, Analysis the mechanism of Rhy, Propos new ideas and OABrections of treatment of OAB for the future.MethodsSD rats are randomly dvided into four groups: Sham operation group;OAB model group; rhynchophylline intervening OAB; Saline-treatment OAB group. Sham operation group: only suture after cut,no treatment;OAB model group: received surgical treatment, OAB model of rat .rhynchophylline intervening OAB:OAB rats are given intraperitoneal injection of rhynchophylline (5ml·kg^-1).Saline-treatment OAB group:OAB rats are given intraperitoneal injection of saline (5ml·kg^-1).Section of urodynamic testing and electrophysiological inOABcators of detrusor are needed. Make isolated rat bladder detrusor muscle strips, wide for 1²mm,length for 5¹0mm,detect the effect of tension on isolated rat bladder detrusor muscle strips and calcium-activated potassium ion channel activator NS1619 and antagonists Ib(Iberiotoxin) by applying the method of tension In vitro. Clarify the effects of Rhy in large conductance calcium-activated potassium channel (BKca) and L-type calcium channel by applying the method of tension In vitro. Verapamil as a control to observe the contraction of detrusor muscle strips and antagonized acetylcholine (ACh) dependent on intracellular and extracellular calcium caused by changes in muscle contraction. ResultsCompared with the OAB group and the saline- treatment group,the rhynchophylline -intervening group is significant in decreasing maximum capacity of the bladder, bladder filling pressure , leak point pressure, contraction frequency and motility index (MI).(P< 0.05). Rhy is as similar as BKca agonist NS1619,affinity index (pD2) are 4.78±0.17,4.53±0.22,BKca antagonist Iberiotoxin can competitive antagonism and make Rhy cumulative dose-response curves parallel to the right, antagonism parameter(pA2) is 7.27±0.16; Rhy1²0μmol/L makes CaCl——2 cumulative dose-response curves to the right of non-parallel, lowers maximum response and shows non-competitive antagonism.ConclusionsRhy inhibit contraction of detrusor by ion channels (blocking ICa-L, activating BKca). Low concentration can inhibit muscle contraction caused by intracellular calcium, but no effect of extracellular calcium.With higher concentration of Rhy on both, the inhibition is more and more obvious. Rhynchophylline plays an important role in the treatment of OAB and decreases effectively on Section of urodynamic testing and electrophysiological inOABcators of detrusor.