Effect of the Hormone Relaxin on the Periodontal Tissues of Animals Primed with Estrogen

¹ Department of Agricultural Biochemistry, University of Arizona, Tucson, Arizona

A study was carried out to determine what effect the hormone relaxin might have on the periodontal tissues of Swiss Albino mice and Golden Syrian hamsters. These animals were first "primed" with estrogen, in the form of estradiol benzoate, followed by the injection of relaxin in both an aqueous and an oily vehicle.

The animals that received the injections of relaxin gained appreciably more weight during the experimental procedure than did the controls. In the mice the gain was statistically significant, while in the hamsters it was not.

The previously reported changes in the pubic ligaments of mice were confirmed.

Changes were found in the pubic area of hamsters. These changes consisted of the replacement of the cartilage joining the pubic bones with a loose, fibrous connective tissue.

The connective tissue of the palate of the animals receiving relaxin was somewhat looser in character than the tissue in the same location in the control animals. This was consistent with other reported effects of relaxin on connective tissue.

The presence of dental calculus, with resulting inflammation, had no effect on the changes observed in the connective tissue of the periodontal ligament in the hamsters.

As a result of the administration of relaxin in animals previously primed with estrogen, the connective tissues of the periodontal ligament showed edematous changes, which have been reported as occurring in other connective tissues of the body. The response to the administraton of relaxin varied from animal to animal but was unmistakably present in most of the animals receiving it.