A new Clamping-Cortisone method for experimental chronic gastric ulcer in rats

Studies on the histological findings

Abstract

In this paper, the details of a new Clamping-Cortisone (C-C) method for making chronic gastric ulcers in rats and the histological findings are presented. Furthermore, changes of the several values and indices, which were obtained from measuring the size of the ulcer and others microscopically, are also described.
The method is as follows: The gastric walls of white male rats weighing 250g wereclamped with an aluminium clamp of 12×4mm in size for 24 hours. Animals were given 7mg of cortisone acetate per 100g of body weight for 7 days after the operation. In the control group, cortisone was not given.
By these procedures, animals developed chronic gastric ulers, which had almost the same size and form, with 100% certainty.
The macroscopic features of these ulcers were quite a resemblance to those of human beings.
In the C-C group of animals, the time needed for complete cure was very much longer than that in the control animals. 75% of the control animals showed a complete cure from the ulcer within 4 weeks, but 43% of the treated animals remained without complete cure for over 10 weeks after the operation.Microscopically, these ulcers also revealed quite a resemblance to those of human gastric ulcers. The findings of excavation, double line ofdemarcation, three or four ulcers layers (of necrotic tissue, of fibrinoid degeneration, of granulation tissue and of cicatrization), and round cell infiltration like lymph follicle and various vascular changes, which are all seen in typical chronic ulcer of human beings, could be observed in these experimental ulcers.It was very interesting that adenomatous prolifilation of atypical glandular cells of the mucosal layer and of abnormal cells, which were quite similar to the epithelial cells of the bile duct, could be found.
Using histological preparats, some measurements were made of the size and several changes of the ulcer, length of defect in the mucosal layer and of the surface of the ulcer, degree of the regenerated mucosa, width of defect of the muscularis mucosa and muscle coat, and thickness of the basal and marginal portion of the ulcer. Analysis of the healing process of the ulcer was made with this data obtained from the measurements and the differences of the data between the treated and control groups were also studied. From these studies, it was clearly proved that the C-C group showed a longer healing process than that of the control group. From this data of the measurements, new ulcer indices were devised for representing the healing processof the ulcer objec-tively. Using the new indices, it was definitely proved that the C-C group had a longer healing process compared with that of the control group.
From the results of these experiments, it is clearly shown that the Clamping-Cortisone method is very useful for studing the many problems of the gastriculcer and for assaying the therapeutic effects of many drugs used for treating human gastric ulcers.