Roles of Adrenergic Drugs in the Renal Pelvic Pacemaker Control of Ureteral Peristalsis

Abstract

Experiments were performed to explore the influence of noradrenaline and isoproterenol on the ureteral peristalsis in the canine pelviureteral system in vitro. The rhythmic changes of intrapel vie pressure no longer became manifest, and simultaneously recorded electromyograms revealed disappearance of peristalsis at sites distal to the upper region of the renal pelvis following application of isoproterenol, while the pacemaker at the pelvicalyceal border continued to discharge at an unaltered rate. It is concluded from our findings that both noradrenaline and isoproterenol act upon conduction of peristalsis rather than on the pacemaker as such, thereby facilitating or inhibiting the conduction, respectively, in their behavior toward ureteral peristalsis. The results also have demonstrated that the renal pelvic pressure recorded during treatment with isoproterenol did not reflect pacemaker activity of the renal pelvis.

Pacemaker activity in the upper urinary tract

“…Isoproterenol also had no affect on the interval of pacemaker discharge, but increased the interval between discharges along the ureter Kondo et al, 1985). Tetrodotoxin and blockers of the autonomic nervous system, both parasympathetic and sympathetic, have little effect on peristalsis suggesting that autonomic neurotransmitters have little role in maintaining pyeloureteral motility (Morita and Tsuchida, 1983;Lang et al, 2001;. Capsaicin-sensitive sensory afferents and the endogenous release of tachykinins and prostaglandins are involved in the maintenance of normal ureteral peristalsis (Lang et al, 2002).…”

Effect of Dibutyryl Cyclic Adenosine Monophosphate on Canine Pelviureteral Discharge Potentials

“…db-cAMP increases the contractile force but slightly decreases the contractile rate in rat heart muscle [12]. In our studies [6,10], a Pi-adrenergic agonist, dobutamine, caused an increase in amplitude but not in the frequency of the pacemaker discharge potentials in the PC region, neither did isoproterenol quicken the discharge frequency in the PC region. In the present study, db-cAMP caused an increase in amplitude but not in the frequency of the pacemaker discharge in the PC region.…”

“…Isoproterenol, a (3-adrenergic agonist, decreases ureteral contractile activity and the effect may be mediated by an increase in cyclic AMP [9]. In our previous study [10]. isoproterenol abolished the ureteral discharge potentials in association with an abolishment of renal pelvic con traction waves.…”

Effects of Dobutamine and Terbutaline on Adenylate Cyclase Activity and Cyclic AMP Content in the Renal Pelvis of Rabbits

“…In the renal pelvis the pacemaker for ureteral peristalsis is located at the pelvicalyceal region where is the border region between the calyces and the renal pelvis [1], It has been reported that the responsiveness of the pacemaker to P-agonists is different from that of the nonpacemaker region of the renal pelvis [2], Also it has been reported that there are significant amounts of P-adrenergic receptors in the rabbit renal pelvis without regional differences in the total density of P-receptors and that there is a difference in the proportion of P-receptor subtypes between the upper and lower portions of the renal pelvis [3]. It was estab lished that cyclic AMP (cAMP) acted as the intracellular second messenger in the response elicited by P-agonists in a variety of smooth muscles [4], Therefore, in the present study we measured the adenylate cyclase (AC) activities and tissue cAMP contents of the rabbit renal pelvis in order to clarify whether cAMP acted as the intracellular messenger in the renal pelvic smooth muscle and dis-cussed the differences in the changes of these substances induced by P-agonists between the pacemaker region and nonpacemaker region of the renal pelvis.…”