praeruptorin-c and Hypertrophy

To investigate the effects of praeruptorin C (Pra-C) on smooth muscle cell (SMC) hypertrophy, intracellular calcium ([Ca2+]i), nitric oxide (NO) content and influence on cellular signal transduction in isolated cultured rat smooth muscle cell (SMC).. Hypertrophied smooth muscle cells (HSMCs) were induced by angiotensin II (Ang II), cell area was measured under inverted microscope. Nitric oxide (NO) concentration was measured using Griess method. [Ca2+]i was measured using Fura-2/AM. The responses to [Ca2+]i elevation stimulated by KCl (60 mmol.L-1 or norepinephrine (10 mumol.L-1) were observed by incubation with phorbol 12-myristate 13-acetate (PMA), staurosporine (ST), the agonist and inhibitor of protein kinase C (PKC), and pertussis toxin (PTX), the sensitive toxin of Gi.. The cell area of SMCs were decreased by 39.01% (P < 0.001) and NO content of SMCs were significantly increased in Pra-C + Ang II group. In presence of 60 mmol.L-1 KCl or 10 mumol.L-1 NE, [Ca2+]i of SMCs in Pra-C + Ang II group was significantly decreased than that of Ang II group (P < 0.001) and closed to the normal group. Incubation of SMCs with PMA, ST and PTX, [Ca2+]i of SMCs in Ang II group was increased by PMA and decreased by ST and PTX, but that of Pra-C + Ang II group was similar to the normal group.. These findings suggest that Pra-C can reduce vascular hypertrophy in isolated rat HSMCs, and this is associated with improvement of SMCs [Ca2+]i level, NO content and cellular signal transdution of PKC and Gi.

Topics: Angiotensin II; Animals; Aorta; Calcium; Calcium Channel Blockers; Cells, Cultured; Coumarins; Female; Hypertrophy; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Nitric Oxide; Rats; Rats, Sprague-Dawley; Signal Transduction

To study the effects of praeruptorin C (pra-C), a pure constituent isolated from "Qian-Hu", the roots of Peucedanum praeruptorum Dunn. (Umbelliferae), on vascular hypertrophy, collagen content, transient [Ca2+]i, NO and vascular response of the thoracic aorta of renovascular and spontaneously hypertensive rats (RHR, SHR).. RHR and SHR were given pra-C 20 mg.kg-1.d-1 for 9 weeks, ig. Blood pressure of both rats were measured using tail cuff manometry. Under inverted microscopy the length and width of the smooth muscle cells were measured by using computer software MICC (Dongnan University). [Ca2+]i of smooth muscle cell (SMCs) was measured with Fura-2/AM. By measuring the specific aminoacid hydroxyproline content, the collagen content was obtained. By using Griess reagent, the NO in the smooth muscle cells (SMCs) was measured.. The intermedia of the thoracic aorta in RHR was enlarged than that of the normal and pra-C groups. The size (length x width) of the SMCs of thoracic aorta from RHR increased 73.4 microns vs nomal 34.5 microns and pra-C 34 microns. The collagen content of thoracic aorta was 39% +/- 6.8% dry weight in RHR, they were 26.5% +/- 3% dry weight in normal and 25.6% +/- 1.1% dry weight in pra-C, RHR vs pra-C. The resting [Ca2+]i of single cell of SMCs was (62 +/- 6) nmol.L-1. In Hanks solution containing CaCl2 1 mmol.L-1, the resting [Ca2+]i of SMCs was (150 +/- 8) nmol.L-1 in normal. (226 +/- 11) nmol.L-1 in RHR. In presence of KCl 60 mmol.L-1, NE 10 mumol.L-1, ANG II 100 nmol.L-1 and ATP 30 mumol.L-1 the [Ca2+]i of SMCs were increased by 128%; 132%; 233% and 152% in RHR, respectively. The pra-C group was similar to the normal group. The resting [Ca2+]i of SMCs was (71 +/- 6) nmol.L-1 in control of SHR, in Hanks solution containing CaCl2 1 mmol.L-1. The resting [Ca2+]i of SMCs was (160 +/- 8) nmol.L-1 in normal, and (362 +/- 18) nmol.L-1 in SHR. In presence KCl 60 mmol.L-1 and NE 10 mumol.L-1 the [Ca2+]i of SMCs were increased by 235% and 200% in SHR, respectively. Pra-C group was similar to normal group. NO of SMCs was decreased 76% in SHR, pra-C group was nearly normal. The pra-C improved vascular responses of the thoracic aorta of RHR.. These results indicate that pra-C improved the vascular hypertrophy by decreasing the size of SMCs cells, collagen content. SMCs [Ca2+]i and increasing NO production.

Topics: Animals; Antihypertensive Agents; Aorta, Thoracic; Calcium; Calcium Channel Blockers; Cells, Cultured; Collagen; Coumarins; Drugs, Chinese Herbal; Hypertension; Hypertension, Renovascular; Hypertrophy; Muscle, Smooth, Vascular; Nitric Oxide; Random Allocation; Rats; Rats, Inbred SHR; Rats, Sprague-Dawley