Chemiluminescence Study of Pe roxynitrite in Experimental Autoimmune Uveitis

The purpose of this study is to evaluate the extent of peroxynitrite generation in the pool of radicals/oxidants from intraocular inflammation using luminol-dependent chemiluminescence(LDCL)method. S-antigen induced uveitis was produced in Lewis rats. The rats were killed at the peak of inflammation, and the retinas and choroids were collected for the LDCL. Sodium bicarbonate was used to confirm the peroxynitrite signal. Superoxide dismutase(SOD), N-nitro-L-arginine methyl ester(LNAME)and aminoguanidine(AG)were tried to evaluate the inhibitory effect of superoxide and nitric oxide. LDCL counts for 6 inflamed and 6 control retina/choroid preparations were 66, 429+/-413 cpm and 13, 941+/-105 cpm, respectively(p<0.01). In the presence of bicarbonate, emission was increased by 125.3+/-6.6%(n=6)and the signal was sustained for 2 hours. SOD, L-NAME and AG suppressed the LDCL by 39.8+/-6.1%(n=3), 20.4+/-4.4%(n=3) and 35.9+/-4.0 %(n=3), These observations suggest that peroxynitrite contributes considerably to the generation of the total pool of reactive species by the cellular infiltrate. The presence of a high level of peroxynitrite, a potent oxidizing and nitrating agent, in inflamed retina may cause irreversible tissue damage to the photoreceptors.

Effects of maximal exercise on blood leukocyte counts and neutrophil activity in athletes / 体力科学

Twenty endurance-trained athletes (five male speed-skaters, eleven male and four female cross-country skiers, 16-18 years) ran on a treadmill by a protocol of incremental graded increase in workload until exhaustion during an endurance training period in off-season summer. Immediately after exercise, all developed peripheral leukocytosis (1.9 times; p<0.01) due mainly to lymphocytosis (2.6 times; p<0.01) with a predominant effect on large granular lymphocyte (natural killer cell) count (5.9 times ; p<0.01) . Monocyte count was also enhanced 2.3 times (p<0.01) . These increases were transitory and returned to the pre-exercise levels 1 h later. Peripheral neutrophilia was also observed by 43% (p<0.01) immediately after exercise and remained elevated by 25% (p<0.01) 1 h after exercise, but a shift to the left did not take place. The capacity of isolated neutrophils to produce reactive oxygen species was assessed by luminol-dependent chemiluminescence which detects mainly myeloperoxidase (MPO) -mediated formation of such hyperreactive oxidants as HOCl. The maximum intensity of chemiluminescence (peak height) upon stimulation with opsonized zymosan was significantly enhanced following exercise (p<0.05) . Similar results were obtained when phorbol myristate acetate was employed as nonphagocytic soluble stimulus (p<0.01), suggesting that the capacity of neutrophils to degranulate MPO rather than phagocytosis was enhanced following exercise. In addition, the enhancements of chemiluminescence were positively correlated with the increase in segmented neutrophil count. These data indicate that maximal exercise not only mobilized mature neutrophils from the marginated pool into the circulation, but also augmented their capacity to generate reactive oxygen species of higher reactivity.

Effect of training on physical exersice-induced changes in non-specific humoral immunity / 体力科学

Although it is generally thought that habitual exercise protects an individual from infections, few careful scientific studies have been conducted. To clarify the influences of physical training on non-specific humoral immunity, both serum opsonic activity, which is a more direct indicator for the strength of non-specific humoral immunity to infections, and serum immunoglobulin and complement levels of 18 healthy male volunteers were assayed before and after a 10-week of training as indices of immuno defense.<BR>The serum levels of three immunoglobulins (IgG, IgA and 1gM) and one complement (C3) were compared prior to and immediately after exercise both before and after training. Paired t-test revealed that before training exercise-induced increases in IgG and C 3 were significant and after training increases in IgG, IgA, IgM and C 3 were significant. But baseline (prior to exercise) levels of these immunoglobulins and complement were significantly suppressed during the training period.<BR>Serum opsonic activity was compared with each other in the same way as serum protein levels. The noutrophilic chemiluminescence Peak Height (PH), which is one of the indicators of serum opsonic activity, was significantly decreased immediately after exercise at the beginning stage of the training. After the training period, serum opsonic activity showed no noteworthy exercise-induced variations and baseline levels were slightly increased during the training period.<BR>These findings suggest that resistance and reactivity to the physical stress are improved and the non-specific humoral immunity, self-defense ability against infections, is considered to be improved by the training.