# Exploration of blood flow regulation to bone in humans

> **NIH NIH R21** · SPAULDING REHABILITATION HOSPITAL · 2020 · $175,150

## Abstract

Without blood flow, bone cannot maintain its integrity. Bone blood flow responds to various local
and systemic factors, however, bone perfusion in humans remains relatively unstudied. We will
investigate key mechanisms that regulate bone perfusion in able-bodied and contrast
responses to those with spinal cord injury (SCI). SCI is a model of chronic reduced loading with
loss of sympathetic regulation. In tibial cortical bone, we will: 1) determine the impact of
compressive loading with and without muscle contractions; 2) determine the impact of vascular
sympathetic activity and systemic perfusion pressure; 3) compare the response between able-
bodied and those with SCI. Acute metabolic needs of bone due to loading increase flow
substantially. In addition, the bone vasculature is innervated by a rich network of sympathetic
nerves that serve a functional purpose in the control of blood flow. A critical limitation to the
study of bone blood flow in humans has been the lack of non-invasive assessments. We
developed a near infrared spectroscopy (NIRS) device to non-invasively assess blood content
in bone and assessed tibial perfusion in response to exercise. Here, we will test the hypothesis
that bone blood flow increases proportional to loading conditions in both able-bodied individuals
and those with SCI. We will also test the hypothesis that there are decreases in blood bone flow
that are proportional to increases in leg vascular sympathetic outflow in the able-bodied, but
that changes in bone blood flow are proportional to changes in blood pressure in those with
SCI. The proposed research will be some of the first to determine the control of bone flow in
humans.

## Key facts

- **NIH application ID:** 9940853
- **Project number:** 5R21AR074054-02
- **Recipient organization:** SPAULDING REHABILITATION HOSPITAL
- **Principal Investigator:** J ANDREW TAYLOR
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $175,150
- **Award type:** 5
- **Project period:** 2019-06-01 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9940853

## Citation

> US National Institutes of Health, RePORTER application 9940853, Exploration of blood flow regulation to bone in humans (5R21AR074054-02). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/9940853. Licensed CC0.

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