Decreases in urinary pheromonal activities in male mice after exposure to 3-methylchoranthrene

Abstract

Many classes of environmental pollutants, which are found at significant levels in the environment, affect the reproductive functions. The gonadal functions of various animals are regulated by pheromones excreted from mating partners. Pheromones in male urine play essential roles in the sexual maturation of female mice. Pheromones are received by sensory neurons in the vomeronasal organ, which innervate to the accessory olfactory bulb (AOB). The effects of a typical aromatic environmental pollutant (3-methylchoranthrene) on excretion of pheromones from male mice were explored based on neuronal Fos responses of the AOB of female mice. On days 1 and 3 after intraperitoneal administration of 3-methylchoranthrene (3-MC), the density of Fos-immunoreactive (Fos-ir) cells in the AOB of female mice after exposure to urine excreted from the administered males was lower than that after exposure to urine from non administered males.These results suggest that 3-MC blocks chemical communication from male to female mice by reducing pheromonal activities.

Modulating role of pheromonal cues from oestrus-specific urine on 3-methylcholanthrene-induced male reproductive toxicity

“…() and Shiraiwa et al . (). McClintock () stated that the pheromones have the ability to exhibit long‐lasting changes in behaviour via the activation of hypothalamic–pituitary–adrenal (HPA) axis.…”

“…Shiraiwa et al . () suggested that 3‐MC would block the chemical communication between male and female mice by reducing sex‐attracting pheromones. In the present investigation, the frequency and duration of visit by the female responders to the urine of 3‐MC‐treated male rats were significantly reduced, which was due to the impaired testosterone production.…”

“…There has been concern about 3‐MC as it causes reduction in the testosterone level (Konstandi et al ., ). Possibly, it suppresses the pheromonal communication between male and female by affecting the pheromonal activities (Shiraiwa et al ., ). Male and female sexual behaviours are known to be influenced by olfactory information.…”