Related Experiment Video
Updated: Jul 5, 2026

Mesenteric Artery Contraction and Relaxation Studies Using Automated Wire Myography
Published on: September 22, 2011
Microtubule depolymerization facilitates contraction of rat aorta via activation of Rho-kinase
Kanchan Chitaley1, R Clinton Webb
1Department of Physiology, University of Michigan, Ann Arbor, MI 48019, USA. kanchanc@umich.edu
Abstract:
This study tests the hypothesis that microtubule (MT) depolymerization facilitates contraction of rat aorta via activation of Rho-kinase. Aortic rings from Sprague-Dawley rats were placed in a muscle bath for the measurement of isometric force generation. Bath temperature was decreased from 37 to 10-20 degrees C (30 min), inducing MT depolymerization. Some vessels were treated with nocodazole (10(-5) M) or colchicine (10(-8)-10(-5) M) to stabilize the MTs in the depolymerized state, and the remaining vessels were treated with dimethyl sulfoxide (DMSO: vehicle). Warming of vessels to 37 degrees C induced a significantly greater contraction in nocodazole- and colchicine-treated vessels as compared with controls, and this increase was blocked by pretreatment with taxol (10(-5) M; a MT stabilizing agent) [force (mg): NOC 1159 +/- 93; COL 1138 +/- 69; DMSO 578 +/- 14; TAX + NOC 526 +/- 43; TAX + COL 538 +/- 90]. Following the sustained contraction in response to rewarming, Rho-kinase inhibition with Y-27632 (10(-5) M) relaxed nocodazole- and colchicine-treated rings to a significantly greater extent as compared to DMSO-treated vessels (percent relaxation: NOC 64 +/- 2; COL 65 +/- 5; DMSO 33 +/- 5). These results support the hypothesis that MT depolymerization facilitates contraction of rat aorta via activation of Rho-kinase.
More Related Videos
07:53Standardized Rat Coronary Ring Preparation and Real-Time Recording of Dynamic Tension Changes Along Vessel Diameter
Published on: June 16, 2022
12:35Optogenetic Inhibition of Rho1-Mediated Actomyosin Contractility Coupled with Measurement of Epithelial Tension in Drosophila Embryos
Published on: April 14, 2023
Related Concept Videos
The Contractile Ring
A small GTPase, RhoA, controls the function and assembly of the contractile ring. RhoA belongs to the Ras superfamily of proteins. The activation of formins by RhoA promotes...
Cell Motility through Blebbing
Blebbing Through the Matrix
In multicellular...
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
MAPK Signaling Cascades
Nitric Oxide Signaling Pathway
Smooth Muscle Contraction
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...