Premium
CHANGES IN VESICULAR DOPAMINE‐β‐HYDROXYLASE RESULTING FROM TRANSMITTER RELEASE
Author(s) -
Fillenz Marianne,
West D. P.
Publication year - 1974
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1974.tb04373.x
Subject(s) - dopamine , vesicle , chemistry , medicine , endocrinology , catecholamine , biology , biochemistry , membrane
—Exposure of rats to 3°C for up to 30 min leads to a decrease of 30 per cent in the dopamine‐β‐hydroxylase activity of the vesicular pellet of the heart; this is greater than can be accounted for by loss of soluble DBH from the two populations of noradrenaline storage vesicles known to be present in the heart. Cold exposure in the presence of α‐methyltyrosine causes a much smaller reduction in dopamine‐β‐hydroxylase activity; this suggests that there is a decrease in transmitter release when synthesis is inhibited. The noradrenaline concentration of the vesicular pellet rises briefly during cold exposure and is then maintained at control levels; the early rise is absent in the presence of α‐methyltyrosine. The use of the noradrenaline : dopamine‐β‐hydroxylase ratio as an index of saturation of vesicular storage capacity suggests that during cold exposure an increased synthesis rate leads to increased filling of vesicles.