AbstractsBiology & Animal Science

Numerous investigators have described morphologic changes attributed to experimentally induced hypersensitivity. Different observers have stressed different lesions, and the recent recognition or sulfonamide hypersensitivity has resulted in further additions to an already long list of tissue alterations. In the experiments forming the basis or this thesis, 77 rabbits were given large doses of horse serum intravenously, and their tissues searched for lesions. An acute arteritis, quite similar to the vascular lesions or periarteritis nodosa was found in 47 cases. Diffuse and focal inflammatory lesions were found in smooth, cardiac and skeletal muscle. The latter changes bore a striking resemblance to the muscle lesions of dermatomyositis, and less closely simulated the muscle changes associated with rheumatoid arthritis. Inflammatory cardiac lesions somewhat reminiscent or the cardiac changes in acute rheumatic fever were also found, but their occurrance in small numbers in control animals vitiated the significance of this experimental result. The joints of 6 animals showed subacute inflammatory changes considerably in excess of any changes seen in control rabbits.