Cardiovascular Interaction of Nicotine, Ergonovine, and Hypercholesterolemia in the Rabbit
Rabbits were treated with nicotine and a hypercholesterolemic diet for 24 weeks. At the initiation of the experiment and at four-week intervals thereafter, the following functions were measured: peripheral circulation through the use of the thermal circulation index (TCI), systolic blood pressure, and coagulation time. After 24 weeks, the heart and vessels of the hind legs were examined for pathological changes. Throughout the course of the experiment, the peripheral circulation was depressed, the systolic pressure elevated, and the coagulation rate speeded. Peripheral pathological changes were minimal and areas of cardiac necrosis observed in a similar previous study were absent. In order to determine the cause of this apparent discrepancy, a second group of rabbits was then similarly treated except that ergonovine was added to the regimen. The 24-week histological examination this time revealed cardiac necrosis in all animals receiving the combined nicotine-cholesterol-ergonovine treatment. This effect had not been obtained with any single member or pair of components of the treatment. Possible explanations for the observed interaction are presented.
- Received January 23, 1961.
- © 1961 American Heart Association, Inc.