Preliminary observations on the mechanical and electrical activity of the rat ureter

Abstract

SUMMARY1. The electrical and mechanical activity have been recorded from the rat ureter in situ.2. The frequency of peristaltic contractions is usually about 25/min, and each peristalsis is preceded by electrical activity which normally travels from the renal end of the ureter towards the vesicular end. The electrical and mechanical activities are closely correlated. 4. The normal electromyogram probably arises in the first 5 mm of the renal end of the ureter, and retrograde activity may arise from a similar region at the vesicular end of the ureter.5. A close arterial injection technique shows that the proximal end of the ureter behaves as if it possessed a-receptors; the distal end behaves as if it had fl-receptors. This conclusion is discussed. PNTRODUCTION Several studies have been made of the functioning of the ureter of various species (Fagge, 1902;Gruber, 1928;Bozler, 1938;Prosser, Smith & Melton, 1955; Kiil, 1957), but few of them have been on the ureter of the rat, and most of them have used the isolated organ. Although much can be learned from such preparations they cannot demonstrate the normal physiology of the organ and, in particular, they are quite unable to throw light on the still unsolved problem of the role of the innervation of the ureter. In this study the electrical and mechanical activities of the rat ureter have been examined in situ, the ureter being undisturbed except for the removal of the peritoneal membrane covering it.

Characterization of .ALPHA.-adrenoceptor subtypes involved in regulation of ureteral fluid transport.

“…Norepinephrine, phenylephrine, and clonidine, all produced an elevation in baseline and contractile pressure, while both prazosin, and yohimbine, produced a small fall in baseline and contractile pressure. It has been reported that norepinephrine, a relatively selective aadrenoceptor agonist, causes an increase in frequency of ureteral peristalsis and in ureteral pressure in vivo (Boatman et al 1967 ;Kaplan et al 1968 ;Tindall 1972;Hannappel and Golenhofen 1974 ;Reid et al 1974 ;Rose and Gillenwater 1974;Tsuchida and Sakamoto 1974;Mayo and Halbert 1981). However, previous studies carried out in the ureter have not addressed the subtypes of aadrenoceptors involved in changes in a-adrenoceptor-induced activities.…”

“…Agonists were dissolved in distilled water, containing 1 mg/ml ascorbic acid and antagonists were dissolved in 75% ethanol to give a concentration of 10 M and then diluted to the desired concentration with distilled water. The concentrations of drugs administred were chosen based on experiments on the ureter by previous investigators (Boatman et al 1967;Kaplan et al 1968;Tindall 1972;Hannappel and Golenhofen 1974;Reid et al 1974;Rose and Gillenwater 1974;Tsuchida and Sakamoto 1974;Mayo and Halbert 1981;Morita et al 1985 …”

“…The role of a-adrenoceptor subtypes involved in the control of ureteral function has not been fully elucidated while it is reported that norepinephrine causes an increase in the frequency of ureteral peristalsis in ureteral pressure (Boatman et al 1967;Kaplan et al 1968;Tindall 1972;Hannappel and Golenhofen 1974;Reid et al 1974;Rose and Gillenwater 1974;Tsuchida and Sakamoto 1974;Mayo and Halbert 1981). We have recently developed an experimental model which permits to assess changes in ureteral peristaltic frequency and bolus volume independently .…”

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

“…[10][11][12]. Figure 4 shows representative tracings of the effect of isoproterenol in the left pyeloureteral preparation (10a) from dog No.…”

Ureteric Function and Upper Urinary Tract Urodynamics in Patients with Stones in Kidney and Ureter

“…However, it was demonstrated that excitation of latent pacemakers by noxious/irritant stimuli occurring during a passage of a stone or a bacterial infection can generate the antiperistaltic contractile waves producing urine reflux toward the kidney (Santicioli & Maggi, 1998). Moreover, in a divided ureter, the normal antegrade electrical activity can be replaced by retrograde contractions occurring in different UUT parts independently (Tindall, 1972). Cellular and molecular processes directing normal ureter development as well as disease mechanisms leading to obstructive uropathies are still unknown (Airik, et al, 2010).…”