Effects of captopril and enalapril on intracellular Ca2+ in vascular smooth muscle cell

• Published in: Zhōngguó yàolĭ xuébào Vol. 17; no. 2; pp. 142 - 145
• Main Authors: QI, J.-H, ZHANG, L, WANG, J, WEI, P.-J, GU, P.-K, JIN, Z.-J, HUANG, M.-Z, WANG, H.-Y
• Format: Journal Article
• Language: English
• Published: Beijing Science Press 01.03.1996
• Subjects: Angiotensin-Converting Enzyme Inhibitors - pharmacology; Animals; Antihypertensive agents; Aorta, Thoracic - metabolism; Biological and medical sciences; Biological Transport, Active; Calcium - metabolism; Captopril - pharmacology; Cardiovascular system; Cells, Cultured; Enalapril - pharmacology; Male; Medical sciences; Muscle, Smooth, Vascular - cytology; Muscle, Smooth, Vascular - metabolism; Pharmacology. Drug treatments; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Calcium; Rat; Rodentia; Smooth muscle; In vitro; Vasodilation; Thoracic aorta; Vertebrata; Mammalia; Animal; Blood vessel; Intracellular; Mechanism of action; ACE inhibitor
• ISSN: 0253-9756

To determine whether angiotensin-converting enzyme inhibitors can affect Ca2+ handling in cultured aortic smooth muscle cells (ASMC) directly. Cultured ASMC derived from rat aorta were loaded with the intracellular Ca2+ ([Ca]2+i) fluorescent indicator Fura 2-AM and digital image processing technique was used. Resting [Ca2+]i was greater in ASMC from SHR vs WKY (P < 0.01). KCl-, norepinephrine (NE)-, and angiotensin II (Ang)-induced [Ca2+]i increases were enhanced in ASMC of SHR vs WKY (220 +/- 6, 212 +/- 8, and 215 +/- 14 vs 199 +/- 6, 202 +/- 7, and 195 +/- 7 nmol.L-1, respectively). Captopril (Cap) and enalapril (Ena) had no inhibitory effect on KCl-, NE-, and Ang-induced [Ca2+]i increases in ASMC of WKY. Cap and Ena inhibited KCl-, NE-, and Ang-increased [Ca2+]i in ASMC of SHR (210 +/- 7, 194 +/- 6, and 201 +/- 6 nmol.L-1, respectively). Ena and nifedipine similarly decreased KCl-, NE-, and Ang-increased [Ca2+]i. Cap blocked KCl-, NE-, and Ang-increased ([Ca2+]i) via a voltage-dependent Ca2+ channel of which function and specificity was altered in ASMC of SHR.