INTERACTION BETWEEN ENDOTELINS-NORADRENERGIC TRANSMISSION IN THE OLFACTORY BULB OF DOCA-SALT RATS

ABRAMOFF T; NABHEN S; HOPE S; GUIL MJ; BIANCIOTTI LG; VATTA MS

NEW ORLEANS, LOUSIANA, USA

Congreso; EXPERIMENTAL BIOLOGY'09; 2009

AMERICAN PHYSIOLOGICAL SOCIETY

We have previously reported that endothelins (ETs) modulate noradrenergic transmission in the olfactory bulb (OB) of normotensive rats. As it has been suggested that ETs are involved in the development and/or maintained hypertension we sought to establish the effect of exogenous ETs on tyrosine hydroxilase (TH) activity and expression in the left and right OB of DOCA-salt rats. Results were expressed as percentage of control group, and statistical analysis was performed by two-way ANOVA and SNK. P values of 0.05 or less were considered significant. Results showed that in the right OB of DOCA-salt rats TH activity and expression were increased by 40% and 145%, respectively (p<0,001, n=8). In the left OB TH expression was unaltered but its activity was increased by 25% (p<0,001, n=8). When right and left OBs of DOCA-salt rats were incubated with 10nM ET-1 or ET-3 TH activity was reduced 31% in the right OB (p<0,001, n=8) but not in left OB.             These findings show that TH activity and expression were different in DOCA-salt rats as compared with control rats. Furthermore, ETs exerted distinct effects on TH in the right and left OBs, supporting an asymmetric functionality as reported in other brain areas, but the significance of this finding is presently unknown. This study suggests that ETs may be involved in the development and/or maintained hypertension in this animal model. (UBACyT B079, CONICET-PIP 5929, ANPCyT PICT-38333)