# CROSSBRIDGE CYCLE KINETICS IN SINGLE SMOOTH MUSCLE CELLS

> **NIH NIH R01** · UNIVERSITY OF VERMONT & ST AGRIC COLLEGE · 1991 · $152,539

## Abstract

Smooth muscle contraction is essential to normal function of
many organ systems in the body.  Therefore, an understanding of
its normal contractile process is required before studying disease
states such as hypertension in which smooth muscle function may
be abnormal.  Smooth muscle is characterized by its slow
shortening velocity and economical useage of ATP during force
production.  These contractile properties may reflect both the
mechanics of the basic force generating element, the myosin
crossbridge, and its cyclic interaction with actin.  To characterize
crossbridge properties in smooth muscle, stare-of-the-art
techniques will be used to measure mechanical responses from a
single smooth muscle cell, isolated from the toad stomach.  The
single cell approach will avoid the heterogeneity of cellular
responses that can occur in multicellular tissue preparations.  To
correlate a smooth muscle cell's contractile capabilities to its
crossbridge properties, changes in cell length will be used as a
means of probing the crossbridge cycle.  In addition to mechanical
perturbations, membrane permeabilized cells will provide the
opportunity to modify the cell's interior chemical environment.
Thus changes in the cell's free intracellular concentrations of
specific ions (e.g. MgATP) and the effect these chemical
perturbations have upon cell mechanics will help identify the
specific steps in the crossbridge cycle.  Finally, a mathematical
model of the crossbridge cycle in smooth muscle, that
incorporates the mechanical data obtained in this proposal, will be
used to formulate a view of the crossbridge cycle in smooth
muscle to help explain smooth muscle's slow, economical
contraction.

## Key facts

- **NIH application ID:** 3156986
- **Project number:** 5R01AR034872-07
- **Recipient organization:** UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
- **SAM.gov UEI:** Z94KLERAG5V9
- **Principal Investigator:** David M Warshaw
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $152,539
- **Award type:** 5
- **Project period:** 1984-12-01 → 1993-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3156986

## Citation

> US National Institutes of Health, RePORTER application 3156986, CROSSBRIDGE CYCLE KINETICS IN SINGLE SMOOTH MUSCLE CELLS (5R01AR034872-07). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3156986. Licensed CC0.

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