Little is known about changes of ambulatory activity in diabetic animals. The present study was undertaken to determine such activity in streptozotocin (STZ)-induced diabetic rats. In addition, the turnover of dopamine in the rat striatum, which has been thought to be closely related to locomotor activities, was investigated. The results of the present study were as follows: Experiment 1. Ambulatory activity was gradually decreased following increase in the blood glucose level. The degree of the decrease was signficantly related to the elevation of blood glucose level (r=-0.76, p< 0.05) Experiment 2. We measured the turnover rate of dopamine as DOPAC (3, 4-dihydroxyphenylacetic acid)(ng/g)/DA (Dopamine)(ng/g). In diabetic rats, dopamine turnover rate was significantly decreased (STZ-Gronp 0.102± 0.003 vs. Control Group 0.112± 0.003 (p< 0.05)). The ratio of the decrease was also significantly correlated with the elevation of blood glucoseluevel (r==0.693, p< 0.01). It is suggested that the change of dopamine turnover in the striatum may play an important role, at least in part, in ambulatory activity.
Changes in the subsets of spleen lymphocytes in non-treated and Cyclosporin (Cs)-treated NOD mice were anaylsed using immunofluorescent techniques by FACS. The number of spleen cells in non-treated NOD mice aged 120 days was significantly more decreased than that in ICR mice of the same age. All of the percentages of Thy 1.2, Lyt 1 and Lyt 2 positive cells in non-treated NOD mice were significantly increased compared with those in ICR mice. Moreover, both percentages of Thy 1.2 and Lyt 1 positive spleen cells in Cs-treated NOD mice were significantly decreased compared with those in non-treated NOD mice, while no significant difference was observed in the percentage of Lyt 2 positive spleen cells between non-treated and Cs-treated NOD mice. The ratio of Lyt 1+ cells/Lyt 2+ cells in Cs-treated NOD mice was significantly more decreased than that in non-treated NOD mice. These results suggest that Cs may exert its suppressive effect on development of insulitis in NOD mice by altering the compartmentalization of lymphocyte subsets.