[Countermeasures for hypofunction of gut associated lymphoid tissue during TPN in rats].

Total parenteral nutrition (TPN) causes atrophy of the intestinal mucosa, resulting in the degeneration and atrophy of gut associated lymphoid tissues (GALT). This suppressive effect of TPN on GALT was examined using rats. In rats receiving TPN for 2 weeks, a decrease and atrophy of Peyer's patches and a decrease in thoracic duct lymphocytes (TDL) were observed. Daily oral administration of 1000 mg/kg PSK to the rat in the TPN group corrected the number and size of Peyer's patches, and the number of TDL and its subsets were also improved compared with the TPN group. Diminution of the S-IgA of bile and portal venous blood was noticed during TPN in rats. But the groups PSK administrated were increased the amount of S-IgA in bile and portal venous blood. The immune plasma cells in the Peyer's patches were observed, the number of the MHC-class II, T helper, and IL-2 (T CGF) positive cells were decreased in the TPN group compared with control group (PSK group). It has been concluded, therefore, that PSK is effective for improving GALT inhibition caused by TPN.

Effect of the proteoglycan (PSK) on lymphocyte subsets in normal rats.

The effect of the proteoglycan biologic response modifier, PSK, on lymphocyte subsets was investigated in normal rats. Six-week-old male SPF Wistar-Imamichi rats were fed a diet containing 2% PSK. Peripheral blood lymphocytes (PBL), thoracic duct lymphocytes (TDL), and those existing in the thymus, spleen and Peyer's patches were collected for analysis of subsets of T cells, helper/inducer T (Th) cells, suppressor/cytotoxic T (Ts) cells and B cells compared with those of the control group. In the PBL, differential and absolute counts of T and Th cells were lower in the group fed PSK (the PSK group) than the control group. There was no difference in Ts cells between the groups, and the PSK group showed a higher B-cell differential count. In the case of TDL, the PSK group showed greater absolute counts of T and Th cells than the control group. In tissue lymphocytes, differential T and Th cell counts were significantly greater in the PSK group than the control group, as observed first in Peyer's patches and later in the spleen. No differences between the groups were observed in these counts in the thymus. Changes in body distribution of T and Th cells induced by PSK treatment first appeared in lymphocytes in Peyer's patches, followed by PBL and TDL, and those in the spleen. No such changes were observed in the thymic lymphocytes.

[The effect of a protein-bound polysaccharide (PSK) on lymphocyte subsets of peripheral venous blood and thoracic duct lymph].

To study the effects of a protein bound polysaccharide (PSK) on the immune system in normal animal, lymphocytes subsets of both peripheral (PBL) and thoracic duct lymphocytes (TDL) were analyzed in 6 week old male SPF Wistar-Imamichi rats before and after free feeding of forage which contained 2% of PSK. PBL and TDL were obtained at the time before, 4 weeks after and 8 weeks after administration of PSK. Age matched rats without administration of PSK were used as a control. Following the peripheral blood cell counts were carried out, lymphocytes subsets such as ratio of total T cells helper/inducer T (Th) cell, suppressor/cytotoxic T (Ts) cell and B cell were assayed using W3/13, W3/25, 0 X 8 and 0 X 4 monoclonal antibodies with laser flow cytometric technique (Orthospectrum III Orthodiagnostics). In terms of the PBL, number of total T cells and Th cells in PSK treated group were significantly lower than that of controls. However no statistical different could be obtained between these two groups in relation to the number of Ts cells and B cells. On the other hand, the number of T cells and Th cells in TDL of PSK treated groups were significantly higher than that of controls while Ts cell and B cell number did not show no apparent differences between these two groups. These findings indicate that oral administration of PSK have a potency to accelerate the transport of T cells from blood stream to lymphatic channel and also regulate their distribution in a normal healthy animals.

Effects of oral lentinan on T-cell subsets in peripheral venous blood.

The effect of oral lentinan, a biological response modifier, on the control of systemic immune function was studied in six-week-old male Wistar-Imamichi specific-pathogen free rats. In the lentinan-treated group, 1 mg of lentinan dissolved in 1 ml of physiological saline was administered forcibly into the stomach twice weekly for four or eight weeks. Physiological saline alone was administered in a similar fashion to the control group. Leukocyte and lymphocyte counts were made and lymphocyte subsets measured using monoclonal antibodies W3/13, W3/25, and OX8, and a laser flow cytometry system. The T-cell level, the helper/inducer T-cell level, and the suppressor/cytotoxic T-cell level were measured. The peripheral leukocyte and lymphocyte counts did not change significantly in either group during treatment. After four weeks of treatment, however, the lentinan group had a significantly higher T-cell level, helper-cell level, and helper-suppressor ratio, and a significantly lower suppressor-cell level than did the control group. No significant between-group differences in the lymphocyte subsets or the helper-suppressor ratio were noted after eight weeks of treatment. Oral administration of lentinan appears to modulate the systemic immune function through stimulation of T cells, especially helper cells. Continued administration produced less effect, possibly due to a tolerance to the effect of lentinan.

[Basic studies on oral administration of lentinan (I)--influence on lymphocyte subsets in peripheral venous blood].

The effect of oral administration of lentinan (LTN), a biological response modifier, in the control of systemic immune function was studied in 6-week old male Wistar-Imamichi SPF rats. In the LTN group, 1 mg LTN dissolved in 1 ml physiological saline was administration forcibly into the stomach twice weekly. Physiological saline alone was administered in a similar fashion to the control group. Blood samples were obtained prior to and after four and eight weeks of administration. White blood cells and lymphocyte counts were obtained and lymphocyte subsets were measured using monoclonal antibodies W3/13, W3/25 and 0 X 8 (Sera-Lab), and a laser flow cytometry system (Orthospectrum III, Orthodiagnostic System). The T cell ratio, helper/inducer T (Th) cell ratio, and suppressor/cytotoxic T (Ts) cell ratio were measured. The peripheral white blood cell count and lymphocyte count were not significantly different between the control and LTN groups. After four weeks of LTN administration, however, the LTN group showed a significantly higher T cell ratio, Th cell ratio and Th/Ts cell ratio than did the control group, and the Ts cell ratio was significantly lower. In the groups undergoing administration for eight weeks, no difference was noted in the lymphocyte subsets between the two groups. Oral administration of LTN apparently modulates the systemic immune function through T cell stimulation, especially Th cells, but continued administration may induce a tolerance to the effect of LTN.