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A new cell membrane stationary phase (CMSP) consisting of porous silica coated with active cell membranes is presented for affinity chromatography. By immersing silica into a suspension of cell membranes, the whole surface of silica was covered by the cell membranes due to the irreversible adsorption of silanol groups (Si-OH) on the silica surface and the self-fusion of the cell membranes. CMSP can be used directly as a chromatographic packing material without any additional chemical modification. The surface characteristics, enzymatic activity, and chromatographic behavior of CMSP were investigated. The results obtained from scanning electron microscope, surface energy spectrometer, enzyme assay, and liquid chromatography showed that the surface characteristics of CMSP were very different from that of normal and reversed stationary phases. CMSP was found to have the characteristics of both cell membrane activity and chromatographic separation. Moreover, CMSP, as a chiral stationary phase, could be used for the enantiomeric separation of (• Bay-K8644. The capacity factor of some calcium antagonists on CMSP was found to have a good correlation with their pharmacological actions. It is concluded that CMSP may be used not only as a kind of packing material in bio-affinity chromatography, but also as a tool for studying the interactions bef,,veen a drug and its receptor.Original 0009-5893/00/02

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In order to clarify the mechanism involved in the antiinflammatory activity of atractylenolide I and atractylenolide III from the rhizomes of Atractylodes macrocephala Koidz, their effects on tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) production in peritoneal macrophages were examined. Atractylenolide I and atractylenolide III decreased the TNF-alpha level in LPS-stimulated peritoneal macrophages in a dose-dependent manner, their IC(50) values were 23.1 microm and 56.3 microm, respectively. RT-PCR analysis indicated that they inhibited TNF-alpha mRNA expression. Furthermore, they inhibited NO production in LPS-activated peritoneal macrophages, the IC(50) value of atractylenolide I was 41.0 microm, and the inhibition ratio of 100 microm of atractylenolide III was 45.1% +/- 6.2%. The activity analysis of inducible nitric oxide synthase (iNOS) indicated that they could inhibit the activity of iNOS, their IC(50) values were 67.3 microm and 76.1 microm, respectively. Western blot analysis showed that atractylenolide I and atractylenolide III attenuated LPS-induced synthesis of iNOS protein in the macrophages, in parallel. These results imply that the antiinflammatory mechanism of atractylenolide I and atractylenolide III may be explained at least in part, by the inhibition of TNF-alpha and NO production. Atractylenolide I showed more potent inhibition than atractylenolide III in the production of TNF-alpha and NO in LPS-activated peritoneal macrophages. So, atractylenolide I could be a candidate for the development of new drugs to treat inflammatory diseases accompanied by the overproduction of TNF-alpha and NO.

Abstract-Asymmetrical dimethylarginine (ADMA) is an endogenous inhibitor of NO synthase. Because endothelial NO pathway is compromised in patients with salt-sensitive hypertension, we investigated whether the plasma ADMA can be modulated by chronic salt loading in normotensive salt-sensitive persons and its relationship with NO, and we further determined whether or not dietary potassium supplementation can reverse them. Sixty normotensive subjects (aged 20 to 60 years) were selected from a rural community of Northern China. All of the people were sequentially maintained on a low-salt diet for 7 days (3 g/day, NaCl), then a high-salt diet for 7 days (18 g/day), and high-salt diet with potassium supplementation for another 7 days (4.5 g/day, KCl). After salt loading, the plasma ADMA concentrations increased significantly in salt-sensitive subjects (0.

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