Abstract

Hypertension is a disease of high global burden and a leading risk factor for cardiovascular diseases and related deaths. The pressure natriuresis mechanism, which is an intrinsic response in the kidneys which increases urinary sodium excretion when renal perfusion pressure increases, plays a central role in the long-term regulation of mean arterial pressure. Studies have shown that a sustained impairment of the pressure natriuresis mechanism results in high blood pressure, making hypertension a disease of the kidneys.

Since exercise is recommended as a non-pharmacological treatment to manage hypertension, it is important to understand the means by which exercise is beneficial in hypertensive patients. Since pressure natriuresis is a key component in the regulation of blood pressure, understanding the relationship between exercise and pressure natriuresis is important. This study was designed to determine if voluntary exercise in young normotensive rats (from weaning to adulthood), altered pressure natriuresis.

Thirty-six (36) WKY, normotensive rats were set up into two (2) groups; sedentary (8 males & 8 females) and exercised (10 males & 10 females). Each rat had urinary sodium excretion measured at variable renal perfusion pressures (RPP) - baseline, lowered, and raised. Sodium excretion was measured and plotted against RPP to generate a pressure-natriuresis curve. Both male and female rats, (exercised and sedentary) had significant natriuresis responses to increases in RPP, but the response was greater in female rats than males. Exercise improved the pressure natriuresis relationship in both males and females, resulting in a steeper slope of the pressure natriuresis curve. This means that exercised rats had a greater increase in sodium excretion for any given increase in RPP. Our findings therefore demonstrated that exercise improves the pressure natriuresis relationship in both male and female rats, and this may partially explain the beneficial effects of exercise in hypertensive patients.

Advisor

Penny Knoblich

Committee Member

Michael Bentley

Committee Member

Rachel Cohen

Date of Degree

2020

Language

english

Document Type

Thesis

Degree

Master of Science (MS)

Program of Study

Biology

Department

Biological Sciences

College

Science, Engineering and Technology

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Rights Statement

In Copyright