Role of the vomeronasal organ on the estral cycle reduction by pheromones in the rat

Abstract

The role of he vomeronasal organ on the estral cycle reduction induced by pheromones is studied in adult female wistar rats.The animals were divided in three groups: I, intact rats; II, vomeronasalectomized rats (VNX); and III, sham operated rats (sham).Each group was submitted to another three distinct conditions from the day they were weaned (21 days old): Isolated female rats; with male odors from two adult males of tested sexual potency, and isolated rats again.The isolated intact rats show mainly 5 day length cycles.The groups I and III (intacts and sham) with male odors, show 4 day length cycles.The VNX animals show 5 day cycles in any one experimental conditions.These results support the idea that the vomeronasal organ is the receptor of the male reducing cycle pheromone in the female rat.