0
TECHNICAL BRIEFS

A Novel Single-Photon Counting Technique Applied to Highly Sensitive Measurement of [Ca2+]i Transient in Human Aortic Smooth Muscle Cells

[+] Author and Article Information
Shigeru Tada

Energy Phenomena Laboratory, Department of Mechanical Engineering and Science, Tokyo Institute of Technology, 2-12-1 Meguro-ku, Tokyo 152-8859, Japanstada@mech.titech.ac.jp

Ken Okazaki

Energy Phenomena Laboratory, Department of Mechanical Engineering and Science, Tokyo Institute of Technology, 2-12-1 Meguro-ku, Tokyo 152-8859, Japan

J Biomech Eng 128(5), 777-781 (Apr 28, 2006) (5 pages) doi:10.1115/1.2264396 History: Received March 16, 2005; Revised April 28, 2006

This study demonstrates that aequorin, a luminescent natural dye, is useful for vascular cell intracellular Ca2+ concentration ([Ca2+]i) determination. A new single-photon counting technique was developed to resolve the effects of fluid flow shear stress on [Ca2+]i in human aortic smooth muscle cells (HASMCs). Confluent HASMCs were grown on petri dishes loaded with aequorin. Then the dishes were placed in a luminometer chamber after the physiological level of shear stress was applied to the HASMC surfaces. The chamber was housed inside a highly sensitive photomultiplier tube. It detected ultraweak photon emission in response to the [Ca2+]i transient. In the presence of 2.0mM extracellular Ca2+, a shear stress of 12dyncm2, applied for 60s to the top surface of the HASMC monolayer, elicited a sharp increase in [Ca2+]i.

FIGURES IN THIS ARTICLE
<>
Copyright © 2006 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

(a) Light-shield housing. (b) Diagram of shear loading apparatus for exposing HASMCs to shear stress on a collagen-coated 35-mm petri dish. (c) A block diagram of the highly sensitive photon-counting system.

Grahic Jump Location
Figure 3

(Top) Effect of shear stress of 16dyn∕cm2 on [Ca2+]i. (Bottom) Time variation of light emission intensity of [Ca2+]i in the absence of fluid flow shear stress. Graphs are the average light emission response of four experiments. Error bars represent mean ±SD. ∗, significant difference (P<0.01) from the Control group.

Grahic Jump Location
Figure 2

Transient of the intensity of biophoton. “HASMCs” in the figure denotes the intensity of biophoton emission from HASMCs whereas “Control” denotes that of background noises.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In