The effect of different stimuli applied in several parts of the digestive tract on blood pressure was studied in unconscious Wistar rats. Gastric distension and electrical and pinching stimuli produced a significant increase in both systolic and diastolic arterial blood pressure. When different gastric zones were stimulated by either electrical or pinching stimuli, the highest pressor response was found in the antropyloric zone. The stimuli applied to the small intestine, outside the duodenum, did not modify the blood pressure. The pinching of the abdominal peritoneum caused a pronounced (P less than 0.001) blood pressure decrease. These data suggest that the pressor response to gastric distension could be mediated by gastric mechanoreceptors. The pressor response observed after stimulation of the gastric antropyloric zone suggests that this area has a greater number of mechanoreceptors.