on hypertensive rats were tested. In rats given a diet containing CS-FA or FA, elevation of systolic blood pressure was suppressed compared to the control diet group, but no difference in food intake or body weight was observed between groups.

A chitosan (CS) powder treated with cinnamic acid and an analogue compound (CN) was prepared as CS-CN. Using it, bile acid adsorption by CS-CN and the release of CN were investigated in vitro. When CS-CN was soaked in a taurocholate solution, it released CN and simultaneously adsorbed the bile acid. For CS-CN prepared with cinnamic acid, the amount of CN released was 0.286 +/- 0.001 mmol/g CS-CN; the amount of taurocholate adsorbed was 0.284 +/- 0.003 mmol/g CS-CN. These two functions were recognized on alginate or pectin gel beads containing CS-CN. The amount of released CN was altered extensively by the species of CN used for gel-bead preparation. Results suggest that CS-CN is a candidate for complementary medicine to prevent lifestyle-related diseases.

The catalytic site for C4 of C1s has been presumed to consist of a C4-binding domain and a proteolytic domain. A mAb to C1s, M81, blocked C4 activation and C4 binding to C1s. M81 recognized the H chain of C1s. Using M81 as a probe, we tried to define C4-binding site on C1s. Plasmin digestion of C1s generated four products of Mr 58,000 (P1), 48,000 (P2), 37,000 (P3), and 27,000 (P4). These products, except for P2, all possessed a 26,000-Da H chain fragment (26k-HF) connected to variable-sized L chain pieces. 26k-HF alone had an ability to interact with M81. Amino-terminal amino acid analysis of 26k-HF mapped the epitope for M81 to domain IV and/or V of gamma-domain of C1s. The gamma-domain therefore contains the C4-binding site. The confirm and further elucidate the role of the C4-binding site for C4, we used a substrate-blotting technique in which labeled C4 was incubated with nitrocellulose membrane-fixed C1s and its fragments. C4 was successfully blotted onto C1s and P1, but not P2-P4; i.e., further degradation of the L chain led to the loss of C4-binding. During the incubation, most of the added C4 was converted to C4b. The binding was augmented, if the proteolytic activity of C1s and P1 was blocked, so that the added C4 remained intact. Although C4b also bound to C1s and P1, its binding was less effective and abolished by the addition of cold C4. Based on these results, the gamma-domain and the L chain constitute the catalytic site of C1s to activate C4 to C4b. Moreover, the generated C4b, although it still has weak affinity for C1s, can be replaced by newly coming C4.

Our inactivating factor for the fourth component of human complement (C4 INF) was partially purified from pseudoglobulin fraction of C4 deficient human serum. Initially C4 INF was thought to specifically inactivate C4; however, after thorough comparison with highly purified active human esterase (C1s), it became clear that both substances share the following activities: 1) Both substances showed SAC4,2 generating activities on EAC4gp cells as well as on EAC4hu cells. 2) Both substances inactivated C2 as well as C4. 3) Both substances hydrolyzed TAMe. 4) Both substances were sensitive to DFP as well as PMSF. 5) SAC4,2 generating activities of both substances were neutralized by anti-C1s. 6) Both substances were not fixed on either EA or EAC4 cells. 7) Both substances showed antigenic identity against anti-C1s by Ouchterlony analysis. 8) Both substances showed the same electrophoretic mobility on acrylamide gel. 9) Both substances altered the electrophoretic mobility of native C4hu in a similar manner.