The influence of the density of adrenergic innervation on the extracellular steady-state concentration gradient for 3H-noradrenaline.
After inhibition of extraneuronal uptake by corticosterone, isolated right atria and lengthwise halved vasa deferentia of the rat were incubated with 0.2 mumol/l 3H-noradrenaline for 60 min, washed out for 100 min and then prepared for autoradiography. The autoradiographic images were digitized, and silver grain density was determined as a function of the distance from the surface. Silver grain density declined towards the centre of the tissue; the decline was monophasic exponential and significantly steeper in the vas deferens (0.016 microns-1) than in the less densely innervated right atrium (0.011 microns-1). Silver grain density at the surface of the tissue was higher in vas deferens than in right atrium. The results show that the extracellular steady-state concentration gradient for 3H-noradrenaline (generated by uptake1 during the incubation with this amine) largely depends on the density of the adrenergic innervation.
Schömig
E
E
Institut für Pharmakologie und Toxikologie, Universität Würzburg, Federal Republic of Germany.
Azevedo
I
I
Moura
D
D
Trendelenburg
U
U
D000818:Animals; D006325:Heart Atria / Q000294:innervation; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000032:analysis*; D051381:Rats; D013564:Sympathetic Nervous System / Q000502:physiology*; D014316:Tritium; D014649:Vas Deferens / Q000294:innervation
D014316:Tritium; D009638:Norepinephrine