Induction of tyrosine aminotransferase mRNA by glucocorticoids and cAMP in fetal rat liver.
Author(s) -
Norka Ruiz-Bravo,
Michael J. Ernest
Publication year - 1982
Publication title -
proceedings of the national academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.79.2.365
Subject(s) - tyrosine aminotransferase , endocrinology , medicine , in utero , fetus , enzyme inducer , biology , tyrosine , hormone , messenger rna , in vivo , steroid hormone , enzyme , biochemistry , pregnancy , genetics , microbiology and biotechnology , gene
Tyrosine aminotransferase (L-tyrosine:2-oxoglutarate aminotransferase, EC 2.6.1.5) enzyme and mRNA activity were not detectable in day 20 fetal rat liver. Precocious induction of catalytic activity by in utero injection of dibutyryl cAMP was a direct consequence of the de novo appearance of translatable tyrosine aminotransferase mRNA. In contrast, in utero injection of hydrocortisone acetate failed to elicit fetal liver enzyme activity. This failure was due to the inability of the steroid hormone to induce the appearance of tyrosine aminotransferase mRNA activity. In fetal rat liver explants, either compound was capable of stimulating the synthesis of adult levels of enzyme and mRNA. However, catalytic and mRNA activity comparable with that seen in vivo 24 hr after birth required the concerted action of both inducers.
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