期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1975
卷号：72
期号：3
页码：1152-1156
DOI：10.1073/pnas.72.3.1152
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：An increase of cAMP/cGMP concentration ratio is the earliest stimulus-coupled biochemical change that has been measured in the adrenal medulla during the trans-synaptic induction of tyrosine 3-monooxygenase [EC 1.14.16.2 ; L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating)]. In adrenal medulla of rats receiving reserpine alone (16 mumol/kg intraperitoneally) or reserpine and propranolol (40 mumol/kg intraperitoneally 30 min before reserpine), or exposed to 4 degrees for 4 hr, the extent and duration of the increase of the cAMP/cGMP concentration ratio exceeds the critical value that is required to activate the protein kinases (EC 2.7.1.37 ; ATP:protein phosphotransferase). Gel filtration experiments indicate that during this activation, the catalytic subunit of the protein kinase (low-molecular-weight enzyme) is released from the holoenzyme. The activation of protein kinase lasts longer than the increase in the cAMP/cGMP concentration ratio and appears to be an obligatory early event that mediates the increase of tyrosine monooxygenase synthesis. The trans-synaptic induction of the monooxygenase in adrenal medulla appears to be due to an increased synthesis of the enzyme;the rate for monooxygenase degradation is proportional to the number of enzyme molecules that are present at various stages of the induction process.
