Effect of continuous administration of nicotine on urinary histamine and Nτ-methylhistamme levels in the guinea pig

Abstract

The effect of continuous subcutaneous administration of S-(−)- and R-(+)-nicotines on urinary excretion levels of histamine and N τ -methylhistamine in guinea pigs, over a 23-day period, has been studied. Urinary levels of these endogenous compounds were measured utilizing paired-ion reversed-phase high performance liquid chromatography with flow-through electrochemical detection. Urinary histamine levels of animals that had been administered either of these nicotine isomers were not significantly different from control values. Initial levels of urinary N τ -methylhistamine (days 2–3) in R-(+)- and S-(−)-nicotine-treated animals were, 2-fold and 8-fold higher, respectively than control levels but in both cases these levels returned to control values over the remainder of the time course examined (days 6–23). These results suggest that exposure to S-(−)-nicotine results in initial histamine release and/or inhibition of histamine uptake. However, longer term exposure to S-(−)-nicotine may not result in significantly altered levels of circulating histamine.