The In Vitro effect of mercury compounds on noradrenaline output from guinea pig vas deferens

Abstract

An increase in the noradrenaline output induced by organic and inorganic mercury compounds was investigated using isolated vas deferens from guinea pigs. Methylmercuric chloride (MMC, 2.5 × 10 −5 −2 × 10 −4 m ), p -chloromercuri phenyl sulfonate (PCMBS, 2.5 × 10 −5 −10 −3 m ) and HgCl 2 (5 × 10 −5 −2 × 10 −4 m ) were found to be effective in increasing the noradrenaline output in a concentration dependent manner. MMC and HgCl 2 did not require extracellular calcium, but the response to PCMBS was reduced in the absence of extracellular calcium. Thiols, such as cysteine and penicillamine reversibly inhibited the effects of mercury compounds, when added simultaneously with them in equal or in twofold concentrations. It is suggested that the mercury compounds may increase the noradrenaline output from adrenergic nerve terminals by modifying SH groups.