SST-2 tumor inoculation is a useful model for studying the anti-tumor immune response in SHR rats

<p><b>OBJECTIVE</b>The purpose of the present study was to investigate the relation between the dose of tumor cell inoculation (especially the doses less than minimum required to evoke tumor growth) and the anti-tumor immune system, particularly lymphoblast formation and cytotoxic activity of lymphcytes.</p><p><b>METHOD</b>We inoculated rats with various doses of SST-2 tumor cells and examined natural killer (NK) cell activity and lymphoblast formationin vitro.</p><p><b>RESULT</b>The results showed that the cytotoxicities against SST-2 cells and lymphoblast formation of lymphocytes were enhanced by small dose inoculation of tumor cells that could not induce tumor growth.</p><p><b>CONCLUSION</b>It was suggested that was lymphocutes play an important role as an anti-tumor immune system at small doses of tumor inoculation, which appears to reflect an early stage of tumor growthin vivo. It was also suggested that SST-2 tumor inoculation might be a useful model for studying the anti-tumor immune response in SHR rats.</p>

SST-2 Tumor Inoculation is a Useful Model for Studying the Anti-Tumor Immune Response in SHR Rats

Objective: The purpose of the present study was to investigate the relation between the dose of tumor cell inoculation (especially the doses less than minimum required to evoke tumor growth) and the anti-tumor immune system, particularly lymphoblast formation and cytotoxic activity of lymphcytes. Method: We inoculated rats with various doses of SST-2 tumor cells and examined natural killer (NK) cell activity and lymphoblast formation in vitro. Result: The results showed that the cytotoxicities against SST-2 cells and lymphoblast formation of lymphocytes were enhanced by small dose inoculation of tumor cells that could not induce tumor growth. Conclusion: It was suggested that was lymphocutes play an important role as an anti-tumor immune system at small doses of tumor inoculation, which appears to reflect an early stage of tumor growth in vivo. It was also suggested that SST-2 tumor inoculation might be a useful model for studying the anti-tumor immune response in SHR rats.

Chronic Effect of Training on Neutrophil Functions in Humans

We performed this study to evaluate the chronic effect of training on neutrophil functions in humans. Twenty-six university students (14 males and 12 females) with a mean age of 19.1±0.8 years were divided into the athlete group and the control group based on answers given to a written questionnaire. The capacity of circulating neutrophils to ingest bacteria (phagocytosis) and to produce superoxide (nitroblue tetrazolium reduction) was measured under resting conditions in the absence of training activities. In addition, we measured hematological and serum biochemical parameters. The present analyses revealed that the frequency of subjective symptoms concerning susceptibility to infections (sum of males and females) was higher in the athlete group than in the control group (p<0.05). In the investigation of males, hemoglobin and serum protein levels of the athlete group were lower than that of the control group (p<0.01, p<0.05, respectively). Although total and differential leukocyte counts, and phagocytic activity of neutrophils were not significantly different between the groups, superoxide productivity of neutrophils in the male athlete group was higher than that in the control group (p<0.05). Since significant differences were observed in hemoglobin and serum protein levels in the male athletes, the training is considered to have been intense. An increase was noted in the neutrophil superoxide production along with these changes, but no significant difference was observed in the phagocytic activity. Therefore, there is the possibility of superoxide overproduction, which may lead to tissue damage.

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.

Chronic effects of voluntary exercise on SRBC-induced host defense reactions in rats / 体力科学

A study was conducted to evaluate the chronic effects of regular physical activity on nonspecific and specific immune responses. Male Fischer rats (SPF) exercised voluntarily on running wheels for 4 months, and were then injected intraperitoneally with sheep red blood cells (SRBC), followed by measurement of the host defense functions at -2 d, 3h, 24h and 4 d of antigen stimulation. The following results were obtained:<BR>1) The ability of circulating neutrophils to produce superoxide measured by the spontaneous NBT test showed an earlier and higher (p<0.05) rise after SRBC injection in the exercise group, suggesting that neutrophils were activated <I>in vivo</I> more promptly against foreign-body invasion. This might reflect a priming response of neutrophils at the early phase of SRBC-induced host defense reactions modulated by the previous regular exercise.<BR>2) The ability of neutrophils to produce superoxide in response to <I>in vitro</I> stimulation with <I>Staphylococcus aureus</I> 209 P was markedly reduced during inflammatory response in the sedentary group, whereas that in the exercise group was maintained at a constant level. The value at 4 d after SRBC injection in the sedentary group was decreased to more than 20% below the baseline (p<0.02) . In addition, a significantly (p<0.02) lower value than that in the exercise group was shown, although phagocytic activity was similar in the two groups. This suggested that neutrophil bactericidal activity was decreased in the sedentary group.<BR>3) Plasma IgG levels in the exercise group were consistently and significantly (p<0.0001) higher by about 30% than those in the sedentary group, regardless of SRBC injection. This suggested an enhanced host defense status by regular exercise.<BR>4) The specific humoral immune response to SRBC injection was assessed in terms of hemagglutination and plasma IgM levels, but no significant differences were shown between the groups.

Changes in serum immunogloblin levels and neutrophilic phagocytosis after exercise / 体力科学

This paper is intended to give the information we need about personal reactivity to transient loads for the object of estimating human physical fitness. For this purpose, both serum immunoglobulin levels and neutrophilic phagocytosis were assayed as indices to self-defense activities.<BR>To determine the later described reproducibility of experimental results, two independent experiments were made on two different groups -one consisting of twelve and the other of fourteen male voluntary students of our college- exercised in the playgroud. The serum levels of three immunoglobulins (IgG, IgA and IgM) and two complements (C3 and C4), prior to and immediately after exercise, were compared with each other. They rose without exception after exercise.<BR>Paired T-test revealed that in the group of twelve students, rises in IgG, IgA, C3, α-1-antitrypsin and transferrin were significant at P<0.1%, 5%, 5%, 5% and 0.1%, and in the group of fourteen rises in IgG, IgA, IgM, C 3, C 4, α-1-antitrypsin and transferrin were significant at P<1%, 0.1%, 1%, 0.1%, 0.1%, 0.1% and 0.1%, respectively.<BR>In the meantime, the neutrophilic phagocytosis (%) was significantly decreased immediately after exercise in both groups (P-<1% and P-<0.1% respectively) .