Alternative Rat Models of Ureteric Nociceptive Stimulation In Vivo
Nociceptive stimulation in the ureter has also been obtained with modalities other than stones in past studies. One modality was electrical stimulation of the ureter in the unanesthetized rat (Giamberardino et al. 1988, Neurosci Lett 87:29). This model offered the advantage of a stimulus that could be controlled and modulated in intensity; unfortunately, the aversive reactions of the animals (nocifensive behavior, referred muscle hyperalgesia) were inconstant; furthermore, the stimulation adopted was not natural.
Another modality was distension of the renal pelvis after cannulation of the ureteric-pelvic junction; this produced rather variable pseudo-affective responses that were unrelated to stimulus intensity (Brasch and Zetler 1982, Arch Pharmakol 319:161).
A further modality of stimulation was acute distension of the ureter via a catheter in a preparation involving the anesthetized rat: the ureter was cannulated close to the bladder and graded stimuli applied. Roza and...