The relation between in vitro efflux of noradrenaline from platelets and vas deferens in man.

The efflux of isotope-labelled noradrenaline from platelets and vas deferens was compared in 29 healthy males. Platelets and a preparation of tissue from vas deferens were incubated with isotope-labelled noradrenaline until equilibrium in the uptake was obtained. The spontaneous efflux of noradrenaline in buffer was measured for 20 min. There was a significant positive correlation between the efflux of noradrenaline from platelets and vas deferens (r = 0.56, P less than 0.001).