Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)




Many authorities believe that prophylactic treatment of idiopathic hypercholesterolemia will prevent atherosclerosis and plaque formation which almost always precedes clinical arteriosclerosis and subsequent degenerative heart disease. There has been intensive research investigation initiated to provide a pharmacologic agent that will lower elevated serum cholesterol levels in mammals including humans. Several hypocholesterolemic drugs are being tested at the present time, one of the most promising is the dextro-rotary isomer of thyroxine. This study was conducted not only to determine the effects of orally administered dextrothyroxine on pregnancy progression, but also to provide information for further investigations concerning alterations related to hypercholesterolemic pregnant animals. Cardiovascular diseases are by far the leading cause of death in the Western World. Therefore, the need for safe and reliable drugs that might be employed in the prevention and/or treatment of cardiovascular alterations is abundantly clear. Presently, within the United States, three hypocholesterolemic agents are being tested in massive clinical trials: nicotinic acid, ethyl p-chlorophenosyisobutyrate1 and sodium D-thyroxine2, of which D-thyroxine is the most promising. Almost nothing is known concerning the alterations of D-thyroxine in relation to pregnancy progression or its effects involving newborn mammals and/or humans. The possibility of congenital cardiac anamolies must, however, be considered in the light of previous research investigations which indicate that cardiac hypertrophy may occur during D-thyroxine administration. It is hoped that these investigations coupled with the contemplative studies utilizing hypercholesterolemic animals may shed some light on possible cardiovascular alterations caused by D-thyroxine administration during pregnancy. (

Library of Congress Subject Headings

Rabbits -- Breeding




South Dakota State University