Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.5 (RNase)
 17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The RNase protection assay was applied to quantify mRNA expression of five principal mammalian water channels in 18 different rat tissues, and to determine the influence of dehydration on renal water channel expression. Probes consisted of labeled cRNAs transcribed from cDNA fragments of rat CHIP28 (AQP-1, bp 238-575 of coding sequence), AQP-CD (AQP2, bp 53-606), MIWC (AQP4, bp 235-572), GLIP (AQP3, bp 219-604), and AQP5 (bp 56-612). Results were normalized to expression of rat beta-actin by quantitative densitometry of autoradiograms. CHIP28 mRNA was expressed strongly in heart, kidney > placenta, skeletal muscle, and urinary bladder and detected weakly in eye, lung, trachea, spleen, liver, colon, prostate, and skin. AQP-CD was detected only in kidney. MIWC mRNA expression was highest in brain, followed by eye, trachea, lung, stomach, kidney, and skeletal muscle. GLIP was found in eye, trachea, kidney, urinary bladder, skin, prostate, placenta, and skeletal muscle. AQP5 was detected in salivary gland, eye, lung, and trachea. An alternatively spliced form of MIWC (sMIWC) was also identified in lung and kidney by RNase protection assay, corresponding to deletion of exon 2 of MIWC. In response to dehydration (3 days, -15 % body weight), renal expression of CHIP28 and MIWC were unchanged, whereas expression of AQP-CD and GLIP were increased significantly by 2.18 +/- 0.04 and 1.36 +/- 0.11 fold (SE, n = 5), respectively. These results establish quantitative values for aquaporin transcript expression in multiple mammalian tissues. The sensitive RNase protection assay revealed the expression of water channels in several tissues not studied previously or in which mRNA levels were too low to detect by Northern blot analysis. The observation of GLIP up-regulation in kidney by dehydration suggests a role in the urinary concentrating mechanism.
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PMID:Quantitative analysis of aquaporin mRNA expression in rat tissues by RNase protection assay. 867 43

Three members of the water channel (aquaporin) family are expressed in adult rat lung: CHIP28 (AQP-1), MIWC (AQP-4), and AQP-5. Because water channels may be important in the clearance of fluid from the newborn lung, the expression of water channels just before and after birth was investigated using the ribonuclease (RNAse) protection assay. RNA was isolated from lungs, brain, and heart of prenatal rats (fetal days F19, F20, and F21) and postnatal rats (days +1, +2, +5, +7, +21, and adult). Transcript expression was measured relative to a beta-actin control by quantitative densitometry. Whereas beta-actin mRNA expression was nearly constant over time, distinct expression patterns were observed for the three water channels. CHIP28 mRNA expression rose slowly from days F19 to +1, then strongly at day +2, and remained elevated over the first week. MIWC mRNA was weakly expressed prenatally, but strongly increased just after birth. AQP-5 mRNA increased slowly and monotonically between days F20 and +7. These patterns contrasted sharply with the developmental expression of CHIP28 in heart, which decreased over time, and MIWC in brain. Immunocytochemistry showed CHIP28 protein expression in capillary endothelia and MIWC in airway epithelia by day +1; quantitative immunoblot analysis showed increased CHIP28 protein expression over time. These findings are consistent with a role of lung water channels in perinatal fluid clearance; however, proof of physiologic significance will require functional measurements of air space-capillary water permeability.
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PMID:Sharp increase in rat lung water channel expression in the perinatal period. 891 74