First Advisor

Larry I. Crawshaw

Date of Publication

1986

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Biology

Department

Biology

Language

English

Subjects

Hemodynamics, Pregnancy -- Physiological aspects, Heart -- Size

DOI

10.15760/etd.5591

Physical Description

1 online resource (41 p.)

Abstract

Cardiac output Increases by 30-50% during mammal Ian pregnancy. This Increase Is reflected by elevation In both heart rate and stroke volume. The primary mechanism of Increased stroke volume appears to be cardiac enlargement, rather than increased preload, afterload, or contractility. Animal studies have shown that enlargement of the heart occurs prior to an Increase In uterine blood flow during pregnancy and this type of enlargement can be mimicked by sex steroid administration.

Systemic vascular resistance greatly decreases during pregnancy and with sex steroid administration. It has been postulated that systemic vascular resistance may be a signal for heart size changes. This study attempted to chronically decrease systemic vascular resistance by administration of an arterial vasodllator (hydralazlne) over a three week period to guinea pigs. At the time of study hemodynamlcs were measured which Included, heart rate, arterial pressure, right atrial pressure and cardiac output. In vitro left ventricular pressure volume relationships were also evaluated, as was total plasma volume.

Rights

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Comments

If you are the rightful copyright holder of this dissertation or thesis and wish to have it removed from the Open Access Collection, please submit a request to pdxscholar@pdx.edu and include clear identification of the work, preferably with URL

Persistent Identifier

http://archives.pdx.edu/ds/psu/20738

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