ISSN:
1432-2013
Keywords:
Key words Aldose reductase
;
In situ hybridization
;
Macula densa
;
Na+/Cl
;
/betaine cotransporter
;
Na+/myo-inositol cotransporter
;
Osmolytes
;
Sorbitol dehydrogenase
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract It has been suggested that macula densa cells may be exposed to hyperosmotic stress. Since chronic exposure to hypertonic stress causes the amount of intracellular organic osmolytes to increase, the expression of transporters and enzymes that participate in the intracellular accumulation of organic osmolytes was examined using non-radioactive in situ hybridization in the macula densa region of control rats and furosemide-treated animals. Both the sodium- and chloride-dependent betaine transporter (BGT) and sodium-dependent myo-inositol transporter (SMIT) were expressed preferentially in macula densa cells and for both mRNAs the signal intensity was visibly reduced by furosemide. The enzymes aldose reductase (which mediates the conversion of glucose to sorbitol) and sorbitol dehydrogenase (which converts sorbitol into fructose) were expressed not only in macula densa cells but also in the surrounding tubular cells, and the expression was insensitive to furosemide. Thus it remains unclear whether the expression of BGT and SMIT is related to a putative hypertonic juxtaglomerular region.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004240050707
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