Endocrine Stimulation of Healing: A Study of Collagen Formation and Wound Tensile Strength in Pregnant Rats

Abstract

Clinical observations on pregnant women, e.g. of gingival fibro-haemangioma, of increased keloid formation in scars and of healing of peptic ulcer, support the hypothesis that tissue formation and healing might be stimulated during pregnancy. Collagen formation in subcutaneous sponge implants was studied in pregnant rats. In 5 days old sponge implants from the first week of pregnancy the hydroxy-proline concentration and the total amount of hydroxyproline were significantly increased. The results indicated that collagen formation as well as the formation of granulation tissue were stimulated during this phase of pregnancy in the rat.

Determinations of the tensile strength of healing skin incisions showed that the collagen formed in the healing tissue was of functional importance. The tensile strength of 5 days old skin incisions was significantly increased during the first week of pregnancy in the rat. During the third week of pregnancy tensile strength did not differ from tensile strength in a control group of non-pregnant rats, indicating that the stimulation of healing during pregnancy is due to some factor referable to the first third of pregnancy.

The possibility of endocrine stimulation of healing during the early phase of pregnancy is discussed.