The immune response to bovine or pork insulin (BI or PI, respectively) was studied in the rat using the in vitro insulin-induced lymphocyte-proliferation assay. Results indicated that 11 inbred rat strains were divided into categories of high and low responders. Two high responders, SDJ (RT1u) and BN(RT1n) inbred rat strains, appeared to recognize different antigenic determinant(s) on the insulin molecule. The results of linkage and segregation analyses in F1, F2, backcross, and partially congenic rats showed that the Ir gene (Ir-BI), which encodes the high responsiveness in the SDJ rats, is inherited associated with RT1u, whereas the immune suppression gene (Is-BI), which encodes the low responsiveness in the WKA(RT1k) rats, is inherited together with RT1k. The Is-BI is the first major histocompatibility complex (MHC)-linked Is gene reported in the rat. The LEJ(RT1-AuBb) inbred rat strain showed a low response to BI, indicating that Ir-BI is closer to RT1-B/RT1-D region than to RT1-A.

Animals↗

PubMed1983

Accumulation and lethal effect of tritium (tritiated water) in Rhodopseudomonas spheroides. Under light-anaerobic and dark-aerobic conditions.

Nonsulfur purple photosynthetic bacteria, Rhodopseudomonas spheroides cells were cultured in medium containing tritiated water (THO) under the light-anaerobic and dark-aerobic conditions. The experimental R value defined as specific activity ratio of organic bound 3H to THO in medium was 0.49 and 0.48 for the light-anaerobically grown cells and the dark-aerobically grown cells, respectively. From the relation of R value to number of weight doubling of the cells (n), ratio of experimental R to theoretical R, i.e., (2n-1)/2n derived by assuming no isotope effect, was 0.51 and 0.49 on an average for the light-anaerobically grown cells and the dark-aerobically grown cells, respectively. 3H-incorporation from THO-medium into the light-anaerobic nongrowing cells was affected by the light intensity and suppressed by adding HgCl2, KCN, and 2,4-dinitrophenol as well as 3H-labelling in the dark-aerobic nongrowing cells was affected by oxygen tension and suppressed by adding these metabolic inhibitors. From the fractionation of the lyophilized cells by modified Schneider method, the distribution of exchangeable 3H in cold acid-soluble and ether-ethanol-soluble fractions and nonexchangeable 3H bound to small molecules and macromolecules was 7.4/25.3/67.3 in the growing cells cultured anaerobically in the THO-medium up to late exponential phase in the light. The distribution in the nongrowing cells incubated anaerobically with the THO-medium for 18 h in the light of 300 and 3,000 lux was 82.1/8.4/9.5 and 58.2/19.2/22.6, respectively. These distributions of 3H were changed with growth phase and/or incubation time. On the biological effect of 3H-THO for the cells stocked at -196 degrees C to accumulate 3H-decays, the dark-aerobic nongrowing cells labelled with THO were rather radiosensitive than the dark-aerobically and light-anaerobically grown cells cultured in the THO-medium. The killing efficiencies, i.e., the probability that a single disintegration would be lethal, ranged from 1/200 to 1/275 for the above three kinds of cells labelled with THO. The killing efficiencies for R. spheroides labelled with THO were similar to that for radiosensitive strain CB13 and wild strain Hfr of Escherichia coli labelled with 3H-thymidine and stored at -196 degrees C.

Aerobiosis↗

PubMed1983

Immunochemical evidence for multiple beta units of the class II molecule in the rat.

The RT1-B/D region-associated antigens which were serologically defined in the previous study (Ohhashi et al., 1981), were partially purified from membranes of a rat B cell leukaemia, KNL-14. Sequential immunoprecipitation test, with the partially purified 125I-B/Dak preparation using four different rat alloantisera, including a monoclonal antibody, disclosed three distinctive populations of beta units of the class II molecules. Highly purified beta units of three discriminable class II molecules were shown to have different structural properties in terms of molecular weights and of electrophoretic profiles on the isoelectric focusing. The beta units shifted to a position of higher molecular weight on SDS-PAGE under reducing condition, thus suggesting to carry intradisulfide bonds. Furthermore, the highly purified beta units cross-reacted with murine anti-Ia sera. The rebinding test revealed that at least two discriminable species of beta units cross-react with anti-I-Ak monoclonal antibody, whereas beta units purified by binding with the 1E4 monoclonal antibody cross-reacted with anti-I-Ab and/or anti-I-Ad antiserum. On the basis of structural and antigenic properties, we have postulated that the rat class II region can be divided into at least three subregions, each containing a locus which encodes a distinctive beta unit of the class II molecule.

Animals↗

PubMed1983

[Genetic control of the immune response to Streptococcus mutans, insulins and (T,G)-A--L in the rat].

The immune response to Streptococcus mutans antigen, (T,G)-A--L, bovine insulin (B.I.) and pork insulin (P.I.) in the rat was studied by the double antibody method and/or the in vitro antigen-induced lymphocyte proliferation assay. Results were revealed that over ten inbred strains of rats were divided into high and low responders against the each antigen. Two high responders to insulins, SDJ (RT1U) and BN (RT1n) strains of rats were appeared to recognize different antigenic determinant (s) on the insulin molecule. The results of linkage and segregation analyses in F1, F2, backcross and partially congenic progenies were as follows: The immune response genes, Ir-(T,G)-A--L and Ir-B.I., which controlled the high responsiveness against (T,G)-A--L and B.I., respectively, and the immune suppression gene, Is-B.I., which controlled the low responsiveness to B.I. could be assumed. Ir(T,G)-A--L, Ir-B.I. and Is-B.I. were closely linked to RT1, which is the major histocompatibility complex of the rat.

Animals↗

PubMed1982

Accumulation and retention of tritium (tritiated water) in Rhodopseudomonas spheroides under aerobic condition.

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Aerobiosis↗

PubMed1982

Studies on liposome-encapsulated carboquone. IV. Enhancement of antitumor activity of carboquone against Ehrlich ascites carcinoma by encapsulation.

The antitumor effects of liposome-encapsulated carboquone (CQ-liposome) were studied following intraperitoneal administration into mice bearing Ehrlich ascites carcinoma (EAC). CQ-liposome showed nearly 3 times superior efficiencies to parent CQ (free CQ) in the growth inhibitory effect on EAC cells inoculated in mice, and also showed almost the same toxicity as free CQ in normal mice. CQ-liposome prolonged the life span of EAC bearing mice about 2 times that of free CQ. In the results of electrophoresis, it was found that CQ-liposome and EAC cells had positive and negative surface charges, respectively. These observations suggest that CQ-liposome is a favorite delivery system to enhance the efficiency of CQ to EAC in mice. One of the reasons for its excellent effect may be explained by an easy contact of CQ-liposome with EAC cells because of its opposite surface charges.

Animals↗

PubMed1982