Related Experiment Video
Updated: Aug 4, 2026

Subcutaneous Angiotensin II Infusion using Osmotic Pumps Induces Aortic Aneurysms in Mice
Published on: September 28, 2015
Serotonin potentiates angiotensin II--induced vascular smooth muscle cell proliferation
T Watanabe1, R Pakala, T Katagiri
1Department of Internal Medicine, Division of Cardiology, University of Texas-Houston Health Science Center, 6431 Fannin, MSB 6.039, Houston, TX 77030, USA.
Abstract:
Vascular smooth muscle cell (VSMC) proliferation is a key feature in the development of atherosclerosis and restenosis after angioplasty, which can occur in response to many different humoral and mechanical stimuli. We investigated the growth promoting activities of two potent vasoactive substances, angiotensin II (Ang II) and serotonin (5-HT), on cultured rabbit VSMCs. Growth-arrested VSMCs were incubated with serum-free medium containing different concentrations of Ang II in the presence or absence of 5-HT. [3H]thymidine incorporation into VSMC DNA was measured as an index of cell proliferation. Ang II and 5-HT stimulated DNA synthesis in a dose-dependent manner with a maximal effect at 1.75 microM for Ang II (202%) and 50 microM for 5-HT (205%). When added together, low concentrations of Ang II (1 microM) and 5-HT (5 microM) synergistically induced DNA synthesis (363%). Candesartan (1 microM), an AT(1) receptor antagonist, but not PD 123319 (1 microM), an AT(2) receptor antagonist, inhibited the mitogenic effect on Ang II and its interaction with 5-HT. Sarpogrelate (10 microM), a 5-HT(2A) receptor antagonist, and pertussis toxin (10 ng/ml) inhibited the mitogenic effect of 5-HT and its interaction with Ang II. The protein kinase C inhibitor Ro 31-8220 (0.1 microM), the Raf-1 inhibitor radicicol (10 microM), and the MAPK kinase inhibitor PD 098059 (10 microM) abolished mitogenic effects of Ang II and 5-HT, and also their synergistic interaction. The JAK2 inhibitor AG 490 (10 microM) had only a minimal inhibitory effect of Ang II-induced DNA synthesis but significantly inhibited the interaction of Ang II with 5-HT. The synergistic effect on Ang II (1 microM) with 5-HT (5 microM) on DNA synthesis was completely reversed by the combined use of both candesartan (1 microM) and sarpogrelate (10 microM). Our results suggest that Ang II and 5-HT exert a synergistic interaction on VSMC proliferation via AT(1) and 5-HT(2A) receptors. The activation of MAPK and JAK/STAT pathways may explain the synergistic interaction between Ang II and 5-HT.
More Related Videos
06:14Murine Aortic Crush Injury: An Efficient In Vivo Model of Smooth Muscle Cell Proliferation and Endothelial Function
Published on: June 11, 2017
08:28Isolation of Primary Patient-specific Aortic Smooth Muscle Cells and Semiquantitative Real-time Contraction Measurements In Vitro
Published on: February 15, 2022
Related Concept Videos
Regulation of Angiogenesis and Blood Supply
TGF - β Signaling Pathway
Antihypertensive Drugs: Action of β1 Blockers
Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors
Antihypertensive Drugs: Angiotensin II Receptor Blockers
Heart Failure Drugs: Inhibitors of Renin-Angiotensin System