Fifty-seven rats were randomly divided into 6 groups. The ventricular cell action potentials of combined irradiation-burn injury in situ were compared with that of radiation or burn injury and the recovery process from the effect of combined injury on myocardium was observed by floating microelectrode. The results obtained were as follows.Similar to that of radiation or burn injury, both the depolarization and repo-larization of action potential were also changed by combined radiation-burn injury significantly, but there are some peculiar characteristics of its own. Twenty-four hours after combined injury, the amplitude of action potential (APA, -13.6%), maximum depolarization rate, (Vmax, -41.2%) , as compared with that of cort-rol. The changes of heart rate were different. In burn group.it increased by+9.8%; in radiation group, it decreased by -17.4%, however, it appoximated to control level in combined group at 24 hours after injury. Three days after combined injury, the HR was decreased by -12%, after 5 days, it only recovered slightly. Combined injury decreased the mean repolarization rate(MRR, -26.3%--13.2%)and prolonged the duration of action potential (APD), especially APD50 and APD90,( +33.7%-+ 22.9%) and( + 6.9%- + 18%)respectively.These results suggest that the effects of combined injury are not a simple algebraic sum of radiation and burn injury. In some aspects, such as Vmax, there is synergism between the effects of radiation and burn injury, but in other cases, e.g., HR, these effects seem to be counterblanced each other. These changes in ventricular action potentials of the combined radiation-burn injury are also a reversible process. In general, the earlier the response of injury (such as in APA and Vmax) appears, the faster the recovery occurs and vice versa (such as in Vmax and HR) .

Objective To investigate the ultrastructural changes of hippocampus in the guinea pigs with chronic asthma and the effects of hypoxia treatment on the hippocampal ultrastructures. Methods The replicated animal model of chronic asthma was divided into hypoxia(low pressure chamber) treatment group, normal pressure hypoxia inhaling treatment group, non treatment group and control group. The ultrastructural changes of hippocampus were observed with electron microscope. Results Expanded rough endoplasmic reticulum, ruptured cloudy mitochondrion carina, decreased synaptic vesicles and swollen postsynaptic membrane, proliferation of astrocytes and microglia proliferated, swelling of cytoplasm, vacuolation, broadened milieu interspace of blood vessels, swelling of cloudy basement membrane with constricted duct cava were found. After hypoxia, clear neuron nucleoli, plenty organells, slightly expanded rough endoplasmic reticulum, fairly plenty synaptic vesicles, more dense post synaptic membrane and slightly broadened synaptic space were also found. No apparent pathologic changes were found in glial cells and the blood vessels. Conclusion Recurrent chronic asthma may result in the ultrastructural changes of hippocampus due to hypoxia. Treatment with low pressure hypoxia and normal pressure hypoxia may be helpful to the improvement of ultrastructural injury of hippocampus due to asthma.

Objective　To study the effects of irradiation and W11-a12，a kind of repair-promoting drug，on anion-selective channel in membranes of mouse peritoneal macrophage. Methods　The activity of anion-selective channel was recorded from cell-attached patches with patch clamp techniques． Results　The effects of irradiation on anion-selective channel in membranes of peritoneal macrophage included：①decreasing the mean number of activated channels by the presence of zymosan; ②prolonging the mean time from stimulus to the opening of channels; ③depressing the opening of channels by decreasing open-state probability，shortening open-time and prolonging close-time． The effects of irradiation could partly be depressed by W11-a12. Conclusion　Irradiation will depress the anion-selective channel of peritoneal macrophage, which may be an important way to depress the function of macrophage．

Objective: To study the activities of ion channels in macrophages collected from wound. Methods:Using patch clamp technique to study the activities of ion channels.Results:The spontaneous occurrence of channel-induced currents in macrophage collected from wound can be recorded. These currents include cation-selective channel current carried by potassium and anion-selective channel current carried by chloridion. The physiologic function of these ion channels in macrophage collected from wound was discussed in this paper.