Effect of acute and subacute lead exposure on responsiveness of adrenergic system in rat

Lead exposure can induce hypertension in human experimental animals. The exact mechanism of lead-induced hypertension is unknown but many factors such as changes in responsiveness of adrenergic system may be involved. In this study the effects of acute and subacute lead exposure (28 days) on responsiveness of thoracic aorta were aorta and pacing in ice-cold Kreb`s solution at 37 C and gassed with %95 O2 / %5 CO2.Aorta rings were ppaced under optimal resting force of 2 gr for 45 min, and then exposed twice to 40-mmo1/1KC1. The contraction response to the second exposure ti KC1 was taken as refrence for other calculations. The contractile responses were evaluated by adding incremental doses of different factors such as phenylephrine, Prazosin, clonidine, yohimbine, dopamine and SCH in the presence or absence of L-NAME and indomethacin. The results showed that acute and subacute lead exposure significantly increases contractileresponse. It also seems that adrenergic system in not solely resposible for this effect and cyclooxygenase rout may be involved.