# INTERACTIONA & RESPONSES TO STRESS IN VITRO

> **NIH NIH R01** · UNIV OF NORTH CAROLINA CHAPEL HILL · 1992 · $152,771

## Abstract

Tendon injuries, particularly sports related injuries, constitute an
increasing proportion of patients treated at our hospital, yet research in
the cell biology of tendon healing is in its infancy.  Of particular
importance in tendon healing is the relationship of exercise and its
underlying mechanism.  The objective of this study is to explore possible
mechanisms, responsible for the effects of mechanical simulation on tendon
cell biologic (actin polymerization and cell migration) and biochemical
responses (second messengers and matrix adaptations).  Specific aims are:
1. to subject tendon and sheath cells to defined mechanical deformation
regiments where the amplitude, duration, frequency and strain rates are
known; 2. to investigate the mechanism by which mechanical activity is
translated into a biochemical signal;  3. to understand how collagen
metabolism is regulated in cells subjected to defined cyclic stretching in
vitro.  An instrument has been developed in my laboratory that will be used
to apply regulated mechanical strain to collagen coated, flexible bottomed
culture plates that support tendon cell adherence and growth.  A
mathematical expression relating a response of a cell to the mechanical
factors, elongation, frequency and strain rate will be used to model
experiments in culture that mimic physical activity experienced by tendon
and sheath in vivo.  Osteoblasts and endothelial cells are stimulated to
divide by one regimen of cyclic strain whereas smooth muscle cells and pulp
fibroblasts are retarded while tendon cells are refractory.  Other
responses such as alteration in protein synthesis and collagen metabolism
specifically have been noted.  An examination of key second messenger
signalling pathways, such as, cAMP, PGE2, diacylglycerol and
phosphoinositides will be performed using radioimmunoassay, chemical
separation and protein kinase C measurements.  Mitogenic responses of cells
will be assayed by quantitation of DNA synthesis directly in stimulated
cells and in conditioned medium.  Collagen metabolism will be monitored by
quantitation of mRNA, collagen synthesis, type an crosslink quality an
quantity.  Modelling the impact of physical deformation on tendon cells in
culture may yield a quantitative solution to which exercise regimens work
best in vivo to yield a healed tendon that is strong yet flexible.

## Key facts

- **NIH application ID:** 3158419
- **Project number:** 5R01AR038121-06
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **SAM.gov UEI:** D3LHU66KBLD5
- **Principal Investigator:** ALBERT J BANES
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1992
- **Award amount:** $152,771
- **Award type:** 5
- **Project period:** 1987-08-01 → 1994-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3158419

## Citation

> US National Institutes of Health, RePORTER application 3158419, INTERACTIONA & RESPONSES TO STRESS IN VITRO (5R01AR038121-06). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3158419. Licensed CC0.

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