Objectives It has been shown that angiotensin II (Ang II) induces the expression of calponin, a 34 kD actin-binding protein, in vascular smooth muscle cells in vitro. The aim of this study was to investigate whether Ang II can modulate calponin gene expression in rat aorta in vivo. Design Aortic calponin gene expression was studied after chronic exogenous Ang II administration and in Goldblatt hypertension. Methods To investigate the effect of Ang II administration, Sprague Dawley rats were treated for 6 days with a continuous infusion of Ang II (200 ng/kg per min) or saline by osmotic minipumps. The effect of endogenous Ang II on aortic calponin mRNA expression was studied in Goldblatt hypertensive rats with (2K1C model), or without (1K1C model) activation of the renin-angiotensin system. In particular, calponin gene expression in 2K1C rats was studied both at 1 week (2K1C-HR, high renin) and 4 weeks after the onset of hypertension, when plasma renin activity (PRA) was returned to normal values (2K1C-NR, normal renin). Systolic blood pressure (SBP) was measured twice a week. At the end of the experimental period, PRA was measured by radioimmunoassay, and aortic calponin gene expression was measured by Northern hybridization. Results SBP was significantly higher (P < 0.01), whereas PRA was suppressed (P < 0.01), in Ang II versus saline-treated rats. Northern hybridization showed that the aortic calponin gene expression significantly increased (2.5-fold) in Ang II-treated rats (P = 0.01). In Goldblatt hypertensive rats, SBP was significantly higher in 2K1C-HR (P < 0.01), 2K1C-NR (P < 0.01) and 1K1C (P < 0.01) rats compared with the corresponding sham-treated rats. Activation of the renin-angiotensin system was present only in 2K1C-HR rats (P < 0.01), and Northern analysis showed that aortic calponin mRNA expression was significantly increased (2.2-fold) in this group of rats only (P < 0.01). Conclusions Our data demonstrate that both exogenous and endogenous Ang II increase calponin gene expression in aortic smooth muscle cells, independently of the hemodynamic effect of Ang II. (C) 2001 Lippincott Williams & Wilkins.

Castoldi, G., di Gioia, C., Pieruzzi, F., van de Greef, W., Busca, G., Sperti, G., et al. (2001). Angiotensin II modulates calponin gene expression in rat vascular smooth muscle cells in vivo. JOURNAL OF HYPERTENSION, 19(11), 2011-2018 [10.1097/00004872-200111000-00011].

Angiotensin II modulates calponin gene expression in rat vascular smooth muscle cells in vivo

CASTOLDI, GIOVANNA;PIERUZZI, FEDERICO UMBERTO EMILIO GUGLIE;STELLA, ANDREA
2001

Abstract

Objectives It has been shown that angiotensin II (Ang II) induces the expression of calponin, a 34 kD actin-binding protein, in vascular smooth muscle cells in vitro. The aim of this study was to investigate whether Ang II can modulate calponin gene expression in rat aorta in vivo. Design Aortic calponin gene expression was studied after chronic exogenous Ang II administration and in Goldblatt hypertension. Methods To investigate the effect of Ang II administration, Sprague Dawley rats were treated for 6 days with a continuous infusion of Ang II (200 ng/kg per min) or saline by osmotic minipumps. The effect of endogenous Ang II on aortic calponin mRNA expression was studied in Goldblatt hypertensive rats with (2K1C model), or without (1K1C model) activation of the renin-angiotensin system. In particular, calponin gene expression in 2K1C rats was studied both at 1 week (2K1C-HR, high renin) and 4 weeks after the onset of hypertension, when plasma renin activity (PRA) was returned to normal values (2K1C-NR, normal renin). Systolic blood pressure (SBP) was measured twice a week. At the end of the experimental period, PRA was measured by radioimmunoassay, and aortic calponin gene expression was measured by Northern hybridization. Results SBP was significantly higher (P < 0.01), whereas PRA was suppressed (P < 0.01), in Ang II versus saline-treated rats. Northern hybridization showed that the aortic calponin gene expression significantly increased (2.5-fold) in Ang II-treated rats (P = 0.01). In Goldblatt hypertensive rats, SBP was significantly higher in 2K1C-HR (P < 0.01), 2K1C-NR (P < 0.01) and 1K1C (P < 0.01) rats compared with the corresponding sham-treated rats. Activation of the renin-angiotensin system was present only in 2K1C-HR rats (P < 0.01), and Northern analysis showed that aortic calponin mRNA expression was significantly increased (2.2-fold) in this group of rats only (P < 0.01). Conclusions Our data demonstrate that both exogenous and endogenous Ang II increase calponin gene expression in aortic smooth muscle cells, independently of the hemodynamic effect of Ang II. (C) 2001 Lippincott Williams & Wilkins.
Articolo in rivista - Articolo scientifico
angiotensin II; calponin; Goldblatt hypertension; rats
English
nov-2001
19
11
2011
2018
none
Castoldi, G., di Gioia, C., Pieruzzi, F., van de Greef, W., Busca, G., Sperti, G., et al. (2001). Angiotensin II modulates calponin gene expression in rat vascular smooth muscle cells in vivo. JOURNAL OF HYPERTENSION, 19(11), 2011-2018 [10.1097/00004872-200111000-00011].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/35429
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