Detection and hormonal regulation of the mRNA for cytosolic phosphoenolpyruvate carboxykinase in rat lung.
We have studied the presence of the messenger RNA (mRNA) for the cytosolic enzyme, phosphoenolpyruvate carboxykinase (PEPCK), in rat lung by Northern blot hybridization to a complementary DNA (cDNA) probe. Lung from normal rats contained substantial amounts of this mRNA, although its relative concentration was approximately six times lower than in liver. Fasting produced an eightfold increase in the content of the enzyme mRNA in lung, which could be reverted to normal values by glucose refeeding. Induced diabetes also resulted in a sevenfold increase of the levels of PEPCK mRNA in lung. Dexamethasone, thyroid hormone, dibutyryl cyclic adenosine monophosphate (cAMP), histamine, and serotonin also induced important accumulations of the enzyme mRNA without affecting the concentration of beta-tubulin mRNA measured as reference. Thus, the PEPCK gene appears to be regulated in a similar manner in lung and liver. The results suggest that PEPCK may be involved in lung metabolism in starvation, diabetes, and other specific hormonal situations.
Alvarez
L
L
Centro de Biología Molecular (CSIC-UAM), Universidad Autónoma, Madrid, Spain.
García-Ruiz
J P
JP
Nieto
A
A
D000818:Animals; D003600:Cytosol / Q000201:enzymology*; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D006728:Hormones / Q000502:physiology; D008168:Lung / Q000201:enzymology*; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000235:genetics* / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains
D006728:Hormones; D012333:RNA, Messenger; D003907:Dexamethasone; D010729:Phosphoenolpyruvate Carboxykinase (GTP)