Increased expression and activity of phospholipase C in renal arterioles of young spontaneously hypertensive rats.
BACKGROUND
The aims of this study were to document the presence of phospholipase C (PLC) isozymes beta(1), gamma(1), and delta(1) in freshly isolated renal glomeruli and resistance vessels, to compare their expression and activity to that in aorta, and to contrast values between 6-week-old Wistar-Kyoto (WKY) controls and 6-week-old spontaneously hypertensive rats (SHR) during the developmental phase of genetic hypertension.


METHODS
Aorta, preglomerular arterioles, and glomeruli were isolated from 6-week-old rats using standard techniques. PLC isozyme protein level and activity were determined with Western blot analysis and by measuring inositol 1, 4, 5-trisphosphate (IP(3)) production, respectively.


RESULTS
Immunoblots indicate that all three PLC isozymes examined are detectable in freshly isolated preglomerular arterioles, glomeruli, and aorta. Increased levels of PLC-beta(1), and -delta(1) were found in all tested vascular tissues of SHR v WKY. No strain difference was noted for PLC-gamma(1). The relative abundance for both groups was glomeruli > preglomerular arterioles = aorta. The strain difference in protein expression correlated with increased PLC activity in each vascular bed of SHR.


CONCLUSIONS
Protein levels of PLC-beta(1) and -delta(1) and PLC activity are upregulated in the systemic and renal vasculature in 6-week-old SHR, suggesting a role in exaggerated vascular reactivity during the development of genetic hypertension. A more complete understanding of the physiologic roles of PLC isozymes and their contributions to specific aspects of cellular function should advance our understanding of vascular tone/reactivity and hypertrophy/remodeling in normal and hypertensive states.
Peng
Zhangping
Z
Department of Cell and Molecular Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Dang
An
A
Arendshorst
William J
WJ
D000818:Animals; D001011:Aorta / Q000201:enzymology*; D001160:Arterioles / Q000201:enzymology; D015870:Gene Expression; D006973:Hypertension / Q000201:enzymology* / Q000235:genetics; D007527:Isoenzymes / Q000378:metabolism; D007668:Kidney / Q000098:blood supply* / Q000201:enzymology; D007678:Kidney Glomerulus / Q000201:enzymology*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D010738:Type C Phospholipases / Q000235:genetics / Q000378:metabolism*
D007527:Isoenzymes; D010738:Type C Phospholipases