THE CHANGES OF VIP, SP, L-ENK AND SOM IN THE INTESTINE OF RAT EXPOSING TO ACUTE INTESTINAL RADIATION SICKNESS——A Radioimmunoassay, Immunocytochemistry and Microscopic Study / 解剖学报

ABSTRACT

The morphologc observation of immunoreactive structures and the quantitative analysis of VIP, SP, L-ENK and SOM in the small intestine of the control and the irradiated rats were studied by using the methods of immunocytochemistry (ICC) and radioimmunoassay (RIA). Meanwhile, histopathologic study was carried out by light and electron microscope (LM, EM). The results and findings are as follows.. (1) Viewed on LM, no obvious change of the enteric ganglia was found in the small intestine of the irradiated rats; while under EM, the axons and synaptic vesicles showing swelling and vacuolar degeneration was observed. These stuctures have close relation to the transport and release of the neurotransmitter. (2) The normal morphology and the distribution of the immunoreactive nerves and endocrine cells of VIP, SP, L-ENK and SOM were revealed in the intestine of rats by ICC method. Four kinds of immunoreactive peptidergic nerves were confirmed as an important part of the enteric nervous system. No obvious change was found on the structure of the peptidergrc nerves after 2000 rad r-irradiation. The radiosensitivity of the peptide-containing endocrine cells was similar to that of the intestinal epithelium. (3) We first confirmed with RIA that the level of the 4 regulatory peptides remarkably changed in the small intestine of the irradiated rats. Combining the physiologic founctions and the trends of the 4 regulatory peptides, as well as the pathologic characteristics and process after r-irradiation, it is proposed that the 4 kinds of peptide may be involved in the pathologic process of the mucosa damage and the disturbance of intestinal motility etc. in the intestinal radiation sickness of rats.