Goat ureter - an alternative model for measuring ureteral peristalsis.

An alternative model for the measurement of ureteral peristalsis is described using the goat ureter. Ureters from freshly slaughtered goats (Capra aegagous hircus) were collected from a local slaughter house. The peristaltic reflex of these preparations was recorded using a specially designed apparatus. The preparations were mounted so that contractile responses to drugs could be recorded isometrically. Histological studies were undertaken to enable a correlation to be made between the anatomical observations and the functional studies. The spontaneous peristaltic reflex of the goat ureter (7 +/- 2 per 2 min) showed a 50% increase in the frequency of contraction (13.66 +/- 1.6, P<0.001) after application of histamine at a concentration of between 6.512 microM and 13.024 microM, but was blocked completely by 10.4 microM of pheniramine (P>0.05). The reflex was not blocked by the H2 blocker ranitidine (P<0.001). The effects of acetylcholine were variable. Calcium chloride at 6.8 microM resulted in a tetanic response (P<0.001). Nicorandil showed partial inhibition of spontaneous peristaltic reflex at 189.4 microM and complete inhibition at 473.4 microM (P<0.001). Although acetylcholine did not show any appreciable effect on the isometric contractions at a maximum dose of 275.2 microM, adrenaline increased the frequency of contractions by 8.2 +/- 6.5 (P<0.001), while salbutamol and isoprenaline had no effect. The histology revealed a striking resemblance to the human ureter, with a structure that explained the responses obtained. The anatomic, physiologic and histological similarities to the human ureter make it an effective alternative in tropical countries for research on ureteral peristalsis.