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：1982
卷号：79
期号：15
页码：4823-4827
DOI：10.1073/pnas.79.15.4823
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Mechanisms regulating the developmental increase in the activity of adrenal phenylethanolamine-N-methyltransferase (PNMTase), an index of the adrenergic phenotype, were examined. Immunotitration indicated that the increase in catalytic activity in rat adrenal from birth to adulthood was attributable to increased numbers of PNMTase molecules, not enzyme activation. To determine whether the ontogenetic increase in PNMTase protein was associated with elevation of mRNA coding for PNMTase, cell-free translation was performed on total cellular mRNA obtained from adrenals at different ages. Translation in wheat-germ and reticulocyte lysate systems, followed by immunoprecipitation of the PNMTase product, NaDodSO4 gel electrophoresis, and fluorography, showed an 8-fold increase in the proportion of specific PNMTase mRNA relative to total mRNA in rat adrenals from birth to adulthood. Moreover, bovine adrenal medullae exhibited a 100-fold increase in PNMTase mRNA levels between embryonic life and adulthood. Consequently, the ontogenetic increase in adrenal PNMTase appears to be due to a developmental rise in specific mRNA coding for the protein.
