Cyclic nucleotide PDE-3. Quantitation of PDE-3A and -3B mRNAs in rat tissues by RNase protection assay.
Type 3 cyclic nucleotide phosphodiesterase (PDE-3) isoforms exhibit a high affinity ("low K(m)") for cAMP and are specifically inhibited by cGMP and a number of pharmacological agents, which increase myocardial contractility, inhibit platelet aggregation, and increase smooth muscle relaxation. The PDE-3 family consists of at least two isozymes, PDE-3A (cardiac type) and PDE-3B (adipocyte type), with distinct tissue-specific distributions. PDE-3A mRNA is highly expressed in the cardiovascular system, whereas PDE-3B mRNA is primarily expressed in adipocytes and hepatocytes. Toward understanding potential roles of PDE-3 in diabetes mellitus, we have established a specific and sensitive RNase protection assay (RPA) for quantitating PDE-3A and PDE-3B mRNA in rat diabetic models. In fatty Zucker diabetic (ZDF) rats, PDE-3A mRNA, but not PDE-3B mRNA, was expressed in heart, whereas liver and white and brown fat tissues predominantly expressed PDE-3B mRNA. Unexpectedly, PDE-3B mRNA expression was approximately 2.5 times higher than PDE-3A mRNA in aorta from both ZDF and Sprague-Dawley (SD) rats. In contrast, expression levels of PDE-3A mRNA in heart were similar in both species. With this RPA, we were thus able to compare PDE-3A and -3B mRNA levels in different tissues as well as in different rat species.
Nagaoka
T
T
Department of Molecular Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.
Shirakawa
T
T
Kasuya
J
J
Balon
T W
TW
Manganiello
V C
VC
Fujita-Yamaguchi
Y
Y
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000235:genetics / Q000378:metabolism*; D000273:Adipose Tissue / Q000201:enzymology; D000818:Animals; D001011:Aorta; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D004789:Enzyme Activation; D005260:Female; D015870:Gene Expression; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D015336:Molecular Probe Techniques; D009765:Obesity / Q000201:enzymology / Q000235:genetics; D015347:RNA Probes; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011924:Rats, Zucker; D012260:Ribonucleases / Q000378:metabolism*
D007527:Isoenzymes; D015347:RNA Probes; D012333:RNA, Messenger; D012260:Ribonucleases; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4