Expression of three isoforms of Na-K-2Cl cotransporter (NKCC2) in the kidney and regulation by dehydration
| Autor: | Takayuki Uematsu, Takeaki Inoue, Katsumasa Kawahara, Noritada Kobayashi, Takeshi Makino, Taiga Yamazaki, Kimio Tomita, Masashi Mukoyama, Yasushi Nagaba, Yukiko Yasuoka, Hideki Inoue, Yushi Nakayama, Takashi Fukuyama, Yuichiro Izumi, Hiroshi Nonoguchi, Kazuko Itoh |
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| Rok vydání: | 2014 |
| Předmět: |
Gene isoform
Male medicine.medical_specialty Biophysics Gene Expression Bradykinin Kidney Biochemistry Polymerase Chain Reaction Rats Sprague-Dawley Internal medicine medicine Animals Protein Isoforms Dehydration RNA Messenger Molecular Biology DNA Primers Solute Carrier Family 12 Member 1 Messenger RNA Renal sodium reabsorption Base Sequence urogenital system Chemistry Reabsorption Cell Biology medicine.disease Rats Endocrinology medicine.anatomical_structure Renal physiology lipids (amino acids peptides and proteins) Cotransporter |
| Zdroj: | Biochemical and biophysical research communications. 453(3) |
| ISSN: | 1090-2104 |
| Popis: | Sodium reabsorption via Na-K-2Cl cotransporter 2 (NKCC2) in the thick ascending limbs has a major role for medullary osmotic gradient and subsequent water reabsorption in the collecting ducts. We investigated intrarenal localization of three isoforms of NKCC2 mRNA expressions and the effects of dehydration on them in rats. To further examine the mechanisms of dehydration, the effects of hyperosmolality on NKCC2 mRNA expression in microdissected renal tubules was studied. RT-PCR and RT-competitive PCR were employed. The expressions of NKCC2a and b mRNA were observed in the cortical thick ascending limbs (CAL) and the distal convoluted tubules (DCT) but not in the medullary thick ascending limbs (MAL), whereas NKCC2f mRNA expression was seen in MAL and CAL. Two-day dehydration did not affect these mRNA expressions. In contrast, hyperosmolality increased NKCC2 mRNA expression in MAL in vitro. Bradykinin dose-dependently decreased NKCC2 mRNA expression in MAL. However, dehydration did not change NKCC2 protein expression in membrane fraction from cortex and outer medulla and in microdissected MAL. These data show that NKCC2a/b and f types are mainly present in CAL and MAL, respectively. Although NKCC2 mRNA expression was stimulated by hyperosmolality in vitro, NKCC2 mRNA and protein expressions were not stimulated by dehydration in vivo. These data suggest the presence of the inhibitory factors for NKCC2 expression in dehydration. Considering the role of NKCC2 for the countercurrent multiplier system, NKCC2f expressed in MAL might be more important than NKCC2a/b. |
| Databáze: | OpenAIRE |
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