Many investigations related to the kallikrein-kinin system (K-K system) have been done during the past 60 years, and many important discoveries and/or hypotheses concerning the physiological and the pathological meanings of this system have been developed or proposed. However, we have not the sufficient evidence to support most hypotheses ever reported and it should be said that the meanings of this system in the body are still obscure in many cases. In this review, the recent progress and trends of biochemical studies on the K-K system were first described, including such as the discovery of T-kinin, the structural analyses of kininogens and prokallikreins obtained from the analyses of their mRNAs and DNAs, discovery of new function of kininogens as thiol protease inhibitor, the development of a useful kinin antagonist, detection of tissue kallikrein secreted into the circulation system and so on. Recent works revealed that kallikrein widely distributes in the body, such as anterior pituitary, mast-cell, prostate, blood vessels and so on, besides ever known organs, and might hydrolyze atrial natriuretic substance, growth factor, insulin, apolipoprotein etc, besides kinin liberation. Based on these recent informations and the already known facts, the functions of the K-K system were discussed and the problems that we are now confronted in research of this system were also mentioned.

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Several attempts have been already made in our laboratory to determine the order of appearance of various macrophages (Mφ) in the peritoneal cavity or spleen of mice after intraperitoneal (ip) or intravenous (iv) administration of various immunostimulants. Studies to discriminate Mφ of different function were conducted by a newly proposed analysis on their Fcγ receptor (FcγR) expressions : the expression of FcγRs on mouse Mφs obtained by various stimulants were examined by a newly-proposed luminol-dependent chemiluminescence analysis, where different subclass IgGs against hapten (TNP-SRBC) were used for the elicitation of the chemiluminescence from Mφ.
When a live Listeria organism was ip given or killed Corynebacterium parvum was given by iv injection, the appearance of both FcR I and FcR II on day 5 (Listeria), and on day 7 (Corynebacterium) was observed. The former Mφ, which were endowed with listericidal activity, were accompanied by a relatively dominant FcR I expression and the latter, endowed with the lowered Con A induced DNA synthesis, were accompanied by the relatively dominant FcR II expression.
Distinctive discrimination of the effector cells and the suppressr cells on FcγR exprssion was obtained after in vitro or in vivo treatments of inflammatory Mφs with various agents. In vivo and in vitro administration of γIFNαA/D resulted in the appearance of only FcR I on resident peritoneal Mφ. On the other hand, in vivo administration of TAP (immunosuppressive acidic protein) resulted in the appearance of FcR II on spleen Mφ, in parallel with the appearance of suppressor activity on Con A induced DNA synthesis of lymphocytes. Thus it was found that the effector cells tended to express FcR I and the suppressor cells, FcR II.

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Species of Ephedra plants has been shown to have anti-inflammatory activities. Recently, four alkaloids, ephedrine, pseudoephedrine, ephedroxane, isolated from the crude drug “mao”, and chemically synthesized pseudoephedroxane have been reported to have anti-inflammatory activities. For example, these alkaloids suppressed carrageenin-induced hind-paw edema formation in mice. To elucidate the mechanism of the antiinflammatory activities, the effects of “mao” alkaloids on arachidonic acid release and its metabolism in rat peritoneal macrophages stimulated with zymosan particles were examined. When macrophages were stimulated with zymosan, arachidonic acid release and production of arachidonate metabolites such as prostaglandin (PG) E₂, 6-keto-PGF_1α, PGF_2α, LTB₄, and 12-HETE were enhanced. By treatment with dexamethasone, the releace of radioactivity was suppuressed. These four alkaloids also inhibited arachidonic acid release and PGE₂ production.
These results suggest that a part of the anti-inflammatory activities by “mao” alkaloids is attributable to their inhibitory effects on arachidonate metabolism.

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A macrophage-chemotactic factor (MCFS-1) was purified from delayed hypersensitivity skin sites (DHSS) to bovine γ-globulin in guinea pigs. It was a heat-labile glycoprotein with molecular weight (MW) of 150, 000, having both in vivo and in vitro chemotactic activity. Next, a precursor protein of MCFS-1 was purified from guinea pig plasma. It was a single-chain polypeptide of MW of 160, 000 without chemotactic activity. However, chemotactic activity was generated in the precursor fraction during a 2- or 5-day incubation at 37°C or 4°C, respectively. This generation was inhibited by PMSF, suggesting the role of a serine protease (s) . The serine protease was actually separated from the precursor fraction with a benzamidine-conjugated cellulose affinity column. The protease was of a trypsin-like character with MW of 20, 000. By incubation of the precursor with the protease, macrophage-chemotactic activity which was identical immunologically and physicochemically with MCFS-1, was rapidly generated. It suggests an essential role of the protease to generate MCFS-1 in the DHSS. MCFS-1 was also found to activate macrophages to induce increased glucose consumption, release of lysosomal enzymes, and enhance O₂^- release due to cytochalasin E and wheat germ agglutinin.

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Previously, we showed the involvement of cell-mediated immunity and the strain difference in BCG cell wall (CW) -induced lung granuloma response. In the present study, morphological and functional changes in lung macrophages from mice injected intravenously with BCG CW were studied. In BCG CW high-responder mice (C57BL/6 [B6] strain), an increase in the size and the acid phosphatase activity of lung macrophages was observed. These alveolar macrophages showed greater microbicidal activity to M. bovis and Listeria monocytogenes, enhanced superoxide anion production index, and greater macrophage migration inhibition activity, as compared with lung macrophages from BCG CW low-responder mice (C3H/He strain), which were small in size and showed weak acid phosphatase activity, low antimicrobial activity, and low superoxide anion production index upon intravenous injection of the mice with BCG CW. These results indicated that lung macrophages from B6 mice injected with BCG CWs were morphologically and functionally activated, but not those from C3H mice.

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Leukotriene B₄ (LTB₄) and 5-hydroxyeicosatetraenoic acid (5-HETE) are high potency chemotactic factor.
The author demonstrated lipoxygenase products from C¹⁴ arachidonic acid in rabbit ocular tissues. The release of 5-HETE from rabbit ocular tissue was estimated by HPLC and radioimmunoassay technique.
The amount was high inretina, choroid, anterior uvea and conjunctiva in that order.
The present results in dicated that 5-HETE released from blood cell or from vascular tissues.

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Myocardial infarction was induced in rats by ligation of left coronary descending artery and ischemic injury was followed up to 48hr. After the ligation, blood flow resumed into ischemic area from surrounding normal tissue, as known by intensely staining of the marginal zone of the ischemic area with pontamine sky blue, which was injected intravenously one hour before cardiac arrest at each time. Infarct size, evaluated by unstained area of triphenyltetrazolium chloride, reached a plateau at 12hr. Neutrophils were also accumulated from 3hr and then increased extensively from 12 to 24hr. The LTB₄ content in the cardiac tissue was also increased 4 times at 3hr, compared with that in sham operated controls. Single oral administration of a 5-lipoxygenase inhibitor (AA-861) (80mg/kg) one hr before ligation decreased the LTB₄ content to the control and the neutrophil count at 3hr by 40%. Furthermore, the infarct size at 48hr was also suppressed by AA-861 by 34%. Single oral administration of the inhibitor at 2, 8 or 24hr after ligation also suppressed the infarct size by 18, 19 or 19% respectively. These results clearly indicate tht LTB₄ was generated in the ischemic cardiac tissue, attracted neutrophils and indirectly enhanced the exacerbration of the infarct size.

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Thirteen patients with Behçet's disease were treated with OP-1206 (oral PGE₁) of 15μg together with 50-75 mg of Captopril daily for twenty-four weeks. Incidence of oral aphthous ulcers and nodular erythemas was decresed significantly compared with that estimated in patiets who were given OP-1206 or placebo simply. Blood sedimentation rate and serum C-reactive protein from the patients receiving OP-1206 and Captopril improved steadily, and it was also demonstrated that chemotactic index of neutrophils (PMNs) and proportion of activated T cells were significantly decreased in this patients' group. The treatment did not influence production of oxygen intermediates and phagocytosis of PMNs. Combination of OP-1206 and Capto-pril seems to be a beneficial treatment for the patients with severe mucocoutaneous lesions of Behçet's disease.

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In our preceding report, it has been shown that cyclosporin A (CsA, 10 mg/kg/day) administration for 14 days (during the induction phase of immunity), starting on the day of immunization with testicular antigen (TA) -complete Freund's adjuvant (CFA), is effective in preventing experimental allergic orchitis (EAO), delayed skin reactivities to both TA and purified protein derivative of tuberculin (PPD), and antisperm antibody response in strain 13 guinea pigs when examined 2 weeks after immunization.
The present studies showed that even when CsA treatment (30 mg/kg/every other day, for 2 weeks) was started 2 weeks after immunization in the guinea pig, CsA was capable of largely inhibiting orchitoepididymitic lesions, delayed skin response and in vitro lymphocyte proliferative response to both TA and PPD. Antisperm antibody titers were similar in guinea pigs either treated or not treated with CsA. These results suggest that CsA is not effective in preventing helper T cells and B cells for antibody formation which were already developed, and that the suppressive effect of CsA may have a selectivity for certain T-cell subpopulations (including effector T cells relevant to delayed hypersensitivity) .
In addition, CsA inhibited the local adoptive transfer of EAO with lymph node cells obtained from TA-CFA sensitized syngeneic animals, when examined 5 days after cell transfer, if recipients were dosed daily with CsA (10 or 30 mg/kg/day) for 5 days from the time of the cell transfer. These results suggest that CsA may inhibit the action of certain lymphocyte subsets already primed and would support the notion that CsA is also capable of inhibiting processes of the effector phase of immunity.

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We examined the effect of MS-932 (p-acetylaminophenylacetic acid) on the development of glomerular lesions and lymphoma for which abnormalities of immunological functions are responsible in MRL/l mice. MS-932 was administered orally 6 times a week from 8 to 20 weeks of age. MS-932 at doses of 3, 10, 30 and 100mg/kg suppressed the development of proteinuria, and at a dose of 3mg/kg, it lowered the level of increased BUN. MS-932 at doses of 1, 3, 30 and 100mg/kg suppressed the spontaneous production of antidsDNA antibodies in the serum. By the histopathological examination of kidneys, it was found that MS-932 at doses from 1 to 100mg/kg reduced the glomerular lesions. The immunofluorescence studies revealed that IgG deposition in the glomerular capillary membrane and mesangium was slightly reduced by the treatment of MS-932. Furthermore MS-932 at doses of 1, 10 and 30mg/kg suppressed the enlargement of cervical lymph nodes. Such effects caused by MS-932 might be due to the results of the improvement of disordered immunoregulatoly system in MRL/l mice.

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Vascular damage is the occasional manifestations in patients with rheumatoid arthritis (RA) . Using human endothelial cells (EC) as an in-vitro model of vascular tissue, we have examined the injurious effects of polymorphnuclear leucocytes (PMN) from RA patients on EC to investigate the role of PMN on vascular damge in RA. The results obtained are as follows.
(1) The mechanism of EC injury by PMN seemed to be via a non-lytic cell detachment rather than cell death, and there was no difference of injurious capacity between RA-PMN and normal-PMN.
(2) EC injury by PMN was partially inhibited by H₂O₂ scavenger, catalase, but was most prominently inhibited by simultaneous addition of catalase and protease inhibitor, suggesting that both H₂O₂ and protease have an injurious effect.
(3) EC injury by PMN and commercially available H₂O₂ was markedly inhibited by the addition of human serum in advance. The inhibitory effect of normal serum was much stronger than RA serum.
(4) At lower PMN/EC ratio, PMN enhanced the growth of EC, suggesting that PMN release injuryous factors as well as growth-stimulating factor.

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