Effects of male rat urine on norepinephrine levels in the accessory olfactory bulb of young and aged female rats.
Norepinephrine (NE) concentrations in the accessory olfactory bulbs (AOB) of young (4-5 months) and old (25-26 months) ovariectomized Sprague-Dawley rats, which were implanted with a 17 beta-estradiol silastic capsule and then exposed to male rat urine, were studied. The unilateral vomeronasal organ was removed in all rats one week before exposure to the urine stimulation. The NE level in the AOB of this surgical side served as the control. Urine collected from young adult male rats was poured into the female's cage at 12:00h and the animals were sacrificed before and 1, 2, or 3 hours after the male urine was given. The NE basal levels in the AOB of young rats decreased significantly at 14:00h compared to those at 12:00h, while no obvious changes in the NE concentrations were observed in the AOB of old rats during the same period. Two hours after continuous exposure to male urine, the NE concentrations in the AOB of young rats markedly increased, but no similar response occurred in the old rats. These data suggest that the noradrenergic functions in the AOB under basal conditions as well as in response to pheromonal stimulation may be modified with increasing age.
Wang
H J
HJ
Department of Physiology, College of Medicine, National Taiwan University, Taipei, Republic of China.
Tsai
Y F
YF
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D004958:Estradiol / Q000008:administration & dosage; D005260:Female; D008125:Locus Coeruleus / Q000502:physiology; D008297:Male; D009638:Norepinephrine / Q000032:analysis*; D009812:Odorants; D009830:Olfactory Bulb / Q000737:chemistry*; D010052:Ovariectomy; D010675:Pheromones / Q000494:pharmacology* / Q000652:urine; D051381:Rats; D011919:Rats, Inbred Strains
D010675:Pheromones; D004958:Estradiol; D009638:Norepinephrine