The effects of urine on mast cells and smooth muscle of the human ureter

Abstract

Electron microscopy was performed on normal human ureteral rings before and after incubation in human urine for 30 minutes. A large number of mast cells was detected subepithelially and in close proximity to smooth muscle fibres. Treatment with urine (346 mOsm/l) induced various degrees of degranulation in the majority of mast cells. Some membrane bound granules were found free in the surrounding connective tissue and near smooth muscle cells indicating rupture of the cell membrane. In the functional study frequency and amplitude of peristaltic contractions were studied in-vitro. Addition of urine increased frequency and amplitude of peristaltic contractions and addition of the histamine-1-blocker mepyramine (10(-6) M) partially reversed these changes. It can be concluded that in a situation with urothelial damage such as ureteral calculus, urine can penetrate subepithelially and induce degranulation of mast cells with release of mediators. This is followed by forceful peristaltic contractions which are induced by histamine and other newly formed mediators such as prostaglandins. The process is likely to occur in renal colic with impacted kidney stones.

Involvement of Rho‐kinase in the contractile mechanism of human ureteral smooth muscle

“…Ischemia during tissue harvest or transport has also been mentioned as a possible cause [Santis et al, 2003]. Meanwhile, spontaneous activity of human ureteral strips has been observed in vitro by many [Angelo-Khatter et al, 1986;Ugaily-Thulesius and Thulesius, 1988;Nakada et al, 2001]. However, no clear-cut explanation has been made so far regarding the di¡erences in observing spontaneous ureteral contractility.…”

Comparison of Effect of Morphine-Chlorpheniramine Combined Versus Morphine Alone in Alleviating Acute Renal Colic Pain: A Randomized Clinical Trail

“…Furthermore, they showed that under pathological conditions such as renal colic mast cells of ureters releases histamine, which lead to contraction and consequent pain (13). In another study they showed that urothelial damage in ureteral stone can penetrate subepithelially and make degranulation of mast cells mediators that includes histamines (14).…”

Urothelial Cell Platelet-activating Factor Production Mediated by Calcium-independent Phospholipase A2γ

“…Mast cells are present in the subepithelium of the normal human ureter and are activated by urine in vitro (22,23). Activation of mast cells in the ureter has been implicated in pathological conditions such as renal colic and vesicoureteral reflux (24).…”