[The effect of the chronic irritation and pregnancy in the development of the pregnancy tumor. Experimental study in rats].

Abstract

This study was undertaken in purpose to estimate the chronic irritation as an aetiological factor in the development of pregnancy tumor. Wire was attached around the first upper molar of 40 female rats, so that its free ends would irritate the mucosa of the cheek. The rats were divided in groups A, B and C. Group A contained 15 rats which were placed for fertilization 7 days after the irritation started. Group B contained 15 rats which were placed for fertilization immediately after the irritation started. Group C contained 10 rats which remained with the irritation. All rats were sacrificed 50 days after the experiment started and the irritated mucosa of the cheek was removed, fixed in formaline and examined histologically. In 11 rats of group A and in 7 of group B a small size tumor appeared in the irritated region. In the remaining rats, ulceration was present. The histological findings of the tumors were compatible with pregnancy tumors. Our results support that the hormonal changes during the pregnancy consist the primary aetiological factor in the development of pregnancy tumors and that the local chronic irritation acts as a secondary auxiliary factor.