IN VIVO OBSERVATIONS OF THE SMALL MESENTERIC VESSELS DURING PROTRACTED GAMMA IRRADIATION

Microscopic observation of the mesenteric vascular network of the frog during gamma irradiation did not reveal any notable modifications of the circulatory dynamics. It is only after six hours or more of irradiation that a decrease of the anterio-venous caliber by a third with return of endo and perivascular leucocytes is observed. The irradiation of a mesenteric loop permits the observation, in a selective manner, of the vascular modifications without the parenchymous organs being simultaneously affected. (tr-auth)