# AGING AND CARDIOVASCULAR FUNCTION

> **NIH NIH R01** · UNIVERSITY OF HOUSTON · 1993 · $93,291

## Abstract

Significant changes in the cardiovascular system are known to occur with
aging.  Furthermore, it is a fact that approximately 50% of the elderly
population over 65 years of age suffer from hypertension.  This
population makes up 15% of the general population.  In addition,
hypertension can be considered a cardiovascular risk factor in that the
incidence of stroke and myocardial infarction is significantly higher in
elderly people with hypertension.  The mechanisms underlying the
elevation in blood pressure are not clear, although a decrement in
baroreflex function has been implicated.  However, what factors
contribute to baroreflex dysfunction are not known.  The hypothesis to be
tested is that age-related changes in cardiovascular function are due to
alterations in baroreflex function resulting from increased actions of
endogenous opioids.  With this in mind, the specific aims of this
proposal are: 1) to evaluate age-related changes in baroreflex
sensitivity in rats encompassing four age groups (Fischer 344 rats at
6,12,18, and 24 months).  This will be accomplished by first evaluating
baroreceptors in the intact, conscious rat by pharmacologically raising
and lowering blood pressure and observing heart rate changes in response.
Next, the afferent limb and the central components of-the reflex arc will
be isolated and examined via electrical stimulation of the carotid sinus
nerve and nucleus tractus solitarius; 2) to evaluate the role of
endogenous opioids in the regulation of baroreflexes in young and old
rats.  This will be done by manipulating endogenous opioid influences
with appropriate antagonists and evaluating baroreflexes as above; 3) to
determine the central site(s) of action of endogenous opioid modulation
of baroreflexes by selectively microinjecting specific agonists and
antagonists into regions known to participate in cardiovascular
regulation; 4) to evaluate the ability of the cardiovascular system to
respond to a challenge.  In this case, psychosocial stress will be used
to induce hypertension and the effects on baroreflexes and the role of
endogenous opioids examined.  Thus, the experiments described in this
application win shed light on the mechanisms of age-related changes in
cardiovascular function in the elderly and allow for a better
understanding of why blood pressure becomes elevated with age.  As a
result, the best treatment may be selected or new therapeutic methods
developed to treat or prevent cardiovascular dysfunction in the elderly.

## Key facts

- **NIH application ID:** 3121401
- **Project number:** 5R01AG009542-02
- **Recipient organization:** UNIVERSITY OF HOUSTON
- **SAM.gov UEI:** QKWEF8XLMTT3
- **Principal Investigator:** JULIANNA E SZILAGYI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $93,291
- **Award type:** 5
- **Project period:** 1992-09-01 → 1996-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3121401

## Citation

> US National Institutes of Health, RePORTER application 3121401, AGING AND CARDIOVASCULAR FUNCTION (5R01AG009542-02). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3121401. Licensed CC0.

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