Hachiro Senoh

An abnormal ratio of cytochromes in the respiratory chain of mouse and human myelomas

Mouse myeloma cells and mitochondria had the same kinds of cytochrome components in the respiratory chain as the normal ones. Their constitution, however, was abnormally different from that found in normal cells and mitochondria. The cytochrome aa3 concentration was especially low in the myeloma as compared with cytochrome c concentration, and the resulting cytochrome aa3/c ratio was 0.25, which was the lowest ever reported in animal mitochondria. Normal lymph node cells, producing the immunoglobulin similar to the myeloma cells, had a ratio of 1.1. Human myeloma mitochondria had the same characteristics as the mouse myeloma. Ascite form myeloma originated from mouse solid from myeloma grew faster, and yet aa3/c of 0.5 in the ascites myeloma was found to be quite similar to that observed in various ascites tumor cells such as hepatomas, Ehrlich and sarcoma 180. A significant part of the cytochromes in the respiratory chain of the mouse myeloma remained in the oxidized form in the cyanide-inhibited or anaerobic states, and was reduced only by the addition of dithionite. The properties of the b cytochromes in mouse myeloma mitochondria are also described and discussed in the context of multiple forms of the b cytochromes in the respiratory chain.

[Host mediated anti-tumor effect of Nocardia rubra cell wall skeleton on syngeneic tumor in mice].

The mode of action of Nocardia rubra cell wall skeleton (N-CWS) on Meth A fibrosarcoma (Meth A) was studied in BALB/c mice. N-CWS suppressed or regressed the intradermal growth of syngeneic Meth A cells in normal BALB/c and athymic BALB/c mice. The intradermally and subcutaneously infiltrated cells harvested from injection sites of N-CWS in normal mice showed in vitro cytotoxic activity against Meth A cells. Pretreatment of normal BALB/c mice with immunosuppressing agents such as hydrocortisone, carrageenan, or silica particles significantly reduced the anti-tumor effect of N-CWS. The growth of Meth A cells, rechallenged into BALB/c mice in which Meth A cells had once been suppressed or regressed by N-CWS treatment, was also inhibited, but not in similarly treated athymic nude mice. This resistant mechanism was shown to be dependent out cellular components but not on humoral components by the Winn Assay. The present results suggest that N-CWS exerts its anti-tumor activity by mediation of the immune system of the host and that the main effector cells in the early stage of tumor rejection are macrophages; T cells may also be involved in the later stage.