Dependency on sex and stimulus quality of nociceptive behavior in a conscious visceral pain rat model

• Sex and type of mechanical stimulation strongly influence visceral pain. Responses to tonic stimuli are less intense compared those phasic stimuli. influences the responses but not stimulation. Visceral pain behavior may depend on abdominal musculature composition features. Estrogens modulate different pathways activated by be influenced many factors. The aim this study was analyze impact sex quality intracolonic stimulus behavioral manifestations in a preclinical model. Male female young adult Wistar rats were sedated, 5 cm long latex balloon inserted into colon. Sedation reverted recorded. pressure gradually increased using sphygmomanometer. sensitivity measured as contractions response Two types used: phasic. Phasic consisted repeating several times (3x) same short (20 s) within min interval allowing 1 break between individual For maintained throughout whole interval. Both produced pressure-dependent increase contractions. more under than stimulation, with differences depending animals: females exhibited males similar duration at all pressures, whereas pressure-dependently males. tonically stimulated lower sex- or pressure-dependent. In rat, colonic distension stimulus, which also produces sex-dependent that must taken account development models pathology treatments.