Abstract
Abstract
Sprague–Dawley rats were subjected to either repeated breeding with a minimal amount of rest between pregnancies or to repeated pseudopregnancies induced by electrical stimulation of the uterine cervix. Representative numbers of animals from each of the two groups were killed after two, four, and six pregnancies or pseudopregnancies. The multiparous rats developed progressively increasing blood pressure; the blood pressure of pseudopregnant rats remained normal. The multiparous rats manifested progressively increasing adrenal, heart, and kidney weight accompanied by hyperlipidemia, i.e., triglycerides, free fatty acids, and cholesterol, hyperglycemia, and elevated BUN levels vs elevated free fatty acid levels only in pseudopregnant rats. None of the pseudopregnant rats developed aortic sclerosis, whereas the multiparous developed progressively worsening and virtually ubiquitous arteriosclerosis. It is suggested that although pseudopregnancy, like pregnancy, causes alterations in hypothalamic–pituitary function, the hormonal-metabolic conditions are not the same, e.g., absence of extraadrenal glandular activity. The hormonal–metabolic conditions entrained by pseudopregnancy are not conducive to the development of the cardiovascular degenerative changes associated with repeated pregnancy.
Get full access to this article
View all access options for this article.