The effect of prostaglandin synthesis inhibition on motility of the sheep ureter

Abstract

To determine the effect of prostaglandin-synthesis inhibition on ureteral motility, isolated rings of sheep ureters were suspended for recording isometric tension in organ baths filled with Krebs-Henseleit solution. The non-steroidal anti-inflammatory drugs (NSAIDs) indomethacin and diclofenac sodium (10(-5) M) inhibited rhythmic ureteral motility by reducing frequency, amplitude and finally stopping contractions. Prostaglandin F2 alpha, 6-keto-prostaglandin F1 alpha and thromboxane B2 were determined by radioimmunoassay in the bathing solution before and after addition of NSAIDs. Peak contractile activity at 100 min of suspension was associated with increased concentration of all three prostanoids and 50 min after addition of indomethacin and diclofenac sodium when rhythmic contractions stopped, concentration dropped to low levels. The concentration of prostaglandins released into the organ bath were not quantitatively related to the frequency of contractions and therefore do not seem to affect pacemaker activity within ureteral smooth muscle but rather intercellular recruitment of myo-genically active fibres. These findings indicate that prostaglandins play a role in the motor control of the ureter, and that non-steroidal anti-inflammatory drugs exert an inhibitory action.

Eicosanoid Synthesis in the Isolated Human Renal Pelvis, Ureter and Bladder

“…The present study shows that the human upper urinary tract, the renal pelvis and the ureter are able to synthesise eicosanoids, as has been found in the bladder of man (Abrams et al, 1979;Jeremy et al, 1987) and of rabbit (Brown et al, 1980). These results give credance to the study of Al-Ugaily et al (1986), who suggested that the large number of lipophilic granules seen in the vicinity of smooth muscle cells on electron microscopy could serve as prostaglandin precursors and reinforce the results of Thulesius (1987), who found eicosanoid release from sheep ureter into an organ bath.…”

Modulation by stereoselective inhibition of cyclo‐oxygenase of electromechanical coupling in the guinea‐pig isolated renal pelvis

“…indomethacin, produce a profound inhibitory effect on spontaneous or evoked motility of isolated pyeloureteral smooth muscle from various species (Thulesius & Angelo-Khattar 1985;Lundstam et al, 1985;Thulesius et al, 1986;1987;Cole et al, 1988;Kimoto & Constantinou, 1991): the general conclusion emerging from these studies is that prostanoid generation is an important step for the local regulation of pyeloureteral motility. In some studies, a complete suppression of pyeloureteral motility by COX inhibitors has been reported (Lundstam et al, 1984;Thulesius & Angelo-Khattar 1985;Thulesius et al, 1987;Cole et al, 1988): this may suggest that prostanoid generation is mandatory for the maintenance/activation of ureteral peristalsis. The evidence from this approach is, however, strictly limited by the selectivity and specificity of the pharmacological tools employed.…”

Gallbladder Motility in Laparoscopic Cholecystectomy Specimens

“…As reference we had to rely on sheep gallbladder strips which apparently qualita tively responded to cholinergic stimulation like human specimens. The selection of ovine gallbladders was a com promise since these specimens are always readily avail able from freshly slaughtered sheep and we have previous extense experience with smooth muscle preparations from sheep [9] which basically responded in a similar way to human specimens [10]. In our study we chose carbachol as a stimulant of contractility since we found that the nat urally occurring agonist cholecystokinin in a series of 12 experiments only resulted in a 59% efficacy (maximal response) as compared to carbachol (results not shown).…”