FACTORS INFLUENCING THE RATE OF NOREPINEPHRINE BIOSYNTHESIS IN NERVE TISSUE

¹ Department of Physiology, Karolinska Institute, Stockholm, Sweden

isolated guinea-pig vas deferens and the bovine splenic nerve are capable of synthesizing norepinephrine (NE) from L-tyrosine. The rate of synthesis in the splenic nerve tissue is 15 to 20 times that of the vas deferens. In the vas deferens, nerve stimulation causes about a 3-fold increase in the synthesis of NE from tyrosine. This acceleration of NE biosynthesis is independent both of effector organ activity and of the uptake of tyrosine into the tissue. However, in the splenic nerve, stimulation does not alter the synthesis of NE from tyrosine. suggesting that nerve depolarization as such is not the triggering mechanism for acceleration of NE synthesis.