ROS evaluation for a series of CNTs and their derivatives using an ESR method with DMPO.

Carbon nanotubes (CNTs) are important materials in advanced industries. It is a concern that pulmonary exposure to CNTs may induce carcinogenic responses. It has been recently reported that CNTs scavenge ROS though non-carbon fibers generate ROS. A comprehensive evaluation of ROS scavenging using various kinds of CNTs has not been demonstrated well. The present work specifically investigates ROS scavenging capabilities with a series of CNTs and their derivatives that were physically treated, and with the number of commercially available CNTs. CNT concentrations were controlled at 0.2 through 0.6 wt%. The ROS scavenging rate was measured by ESR with DMPO. Interestingly, the ROS scavenging rate was not only influenced by physical treatments, but was also dependent on individual manufacturing methods. Ratio of CNTs to DMPO/ hydrogen peroxide is a key parameter to obtain appropriate ROS quenching results for comparison of CNTs. The present results suggest that dangling bonds are not a sole factor for scavenging, and electron transfer on the CNT surface is not clearly determined to be the sole mechanism to explain ROS scavenging.

Hypertension induced by erythropoietin has a correlation with truncated erythropoietin receptor mRNA in endothelial progenitor cells of hemodialysis patients.

Endothelial nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) contribute to erythropoietin (EPO)-induced hypertension, a major adverse reaction associated with EPO therapy. To investigate the mechanism of EPO-induced hypertension, we examined circulating endothelial progenitor cells (EPCs) taken from 56 hemodialysis (HD) patients. Among these EPCs (which reflect the condition of the endothelium), we looked for EPO receptor (EPOR) mRNAs. A truncated form of EPOR acts as a dominant negative regulator of EPO signaling, leading to hypertension. We found that the ratio of truncated EPOR mRNA in EPCs has a correlation with EPO-induced increase in blood pressure (r = 0.36, P = 0.02). The ratio of truncated to total EPOR mRNA in EPCs had an inverse correlation with EPO-induced cGMP production in vitro (r = -0.31, P = 0.02). A similar correlation was observed in cultured human endothelial cells after transfection of the full-length or truncated forms of EPOR (r = -0.92, P < 0.001). It follows, therefore, that evaluation of EPOR isoform mRNA in EPCs can predict EPO-induced hypertension. The termination of the EPO signal by truncated EPORs may decrease NO/cGMP production after EPO exposure, thereby raising blood pressure.

Human CYP3A4-introduced HepG2 cells: in vitro screening system of new chemicals for the evaluation of CYP3A4-inhibiting activity.

1. The aims were to attest whether HepG2-GS-3A4, a cell line into which the human CYP3A4 gene was introduced, can be used for a screening of chemicals that will inhibit CYP3A4 activity. 2. The capacity of the cells for metabolizing CYP3A4 substrates in vitro was evaluated. Also determined was the effect of CYP3A4 inhibitors and non-inhibitors on nifedipine hydroxylation. Western blot, immunohistochemostry and determination of beta-nicotinamide adenine dinucleotide phosphate (NADPH)-reductase activity were performed. 3. HepG2-GS-3A4 selectively metabolized substrates of CYP3A4 (diazepam, nordiazepam, lidocaine, atorvastatin, and nifedipine) to a greater degree than control. The metabolites were easily detected in the culture medium. Values of V(max) of HepG2-GS-3A4 were about 30- to 100-fold higher than those of the control, while values of K(m) were comparable. Pre-incubation of cimetidine and ketoconazole significantly inhibited nifedipine hydroxylation, while addition of inhibitors specific to other isoforms of CYPs had no substantial effect. The HepG2-GS-3A4 expressed a higher amount of CYP3A4 protein and mRNA than control. Most NADPH reductase activity was detected in microsomal fractions. 4 In conclusion, HepG2-GS-3A4 sufficiently and selectively metabolize substrates of CYP3A4, and inhibitors of CYP3A4 reduced the metabolism. Because the metabolites were easily detected in the culture medium, this cell might be useful for the new and easy screening of new drugs for the evaluation of CYP3A4-inhibiting activity in vitro.

Document recognition and XML generation of tabular form discharge summaries for analogous case search system.

OBJECTIVES: This paper discusses and develops a document image recognition, keyword extraction and automatic XML generation system to search analogous cases from paper-based documents. In this paper, we propose the document structure recognition method and automatic XML generation method for the tabular form discharge summary documents. This paper also develops the prototype system using the proposed method. Evaluation experiments using actual documents are done to discuss the effectiveness of the developed system. METHODS: The developed system consists of the following methods. Paper-based summary documents are scanned by a scanner using 300 dpi first. Noise and tilt of the image are reduced by pre-processing, and the table structures are identified. Characters in the table are recognized and converted to text data by the OCR engine. XML documents are automatically generated using obtained results. RESULTS: In this paper, patient discharge summary documents archived at Mie University Hospital were used. The results show that XML documents can be automatically generated when standard tabular form documents are input into the developed system. In this experiment, it takes about 20 seconds to generate an XML document using the general personal computer. This paper also compares the developed system with a commercial product to discuss the effectiveness of the present system. Experimental results also show that the accuracy of table structure recognition is high and it can be used in a practical situation. CONCLUSIONS: This paper showed the effectiveness of the proposed method to recognize the tabular form document images to generate XML documents.

Indoxyl sulfate stimulates proliferation of rat vascular smooth muscle cells.

Vascular smooth muscle cell (VSMC) proliferation is a key event in the progression of arteriosclerosis. Clinical studies show that uremic toxins deteriorate the arteriosclerosis in renal failure patients. Indoxyl sulfate (IS) is a strong protein-bound uremic toxin, but the effect of IS on VSMC proliferation has not been studied. We examined the effect of IS on rat VSMC proliferation, assessed by a cell counting kit (4-[3-[4-lodophenyl]-2-4(4-nitrophenyl)-2H-5-tetrazolio-1,3-benzene disulfonate] assay) and by [(3)H]thymidine incorporation in vitro. We further evaluated a contribution of mitogen-activated protein kinase (MAPK; p44/42 MAPK) to VSMC proliferation by IS. Immunohistochemical staining was performed for VSMCs using antirat organic anion transporter (OAT)3 antibody. The mRNA expressions of platelet-derived growth factor (PDGF)-A and -C chains, and PDGF-beta receptor were evaluated by real-time PCR. IS stimulated the proliferation of VSMCs in a concentration-dependent manner and activated p44/42 MAPK. Concentration of IS needed to stimulate the proliferation of rat VSMC was about 250 microM, which is compatible with that in the serum of end-stage renal failure patients. PD98059 (10 microM), a selective inhibitor of MAPK/extracellular signal-regulated kinase, inhibited the IS-induced (250 microM) VSMC proliferation and phosphorylation of MAPK. Probenecid (0.5 mM), an inhibitor and substrate of OAT, inhibited the IS-induced (250 microM) VSMC proliferation. Rat OAT3 was detected in VSMCs. The mRNA expressions of PDGF-C chain and PDGF-beta receptor were significantly increased by IS. We conclude that IS directly stimulates rat VSMC proliferation and activates MAPK in vitro. This might be one of the mechanisms underlying the progression of atherosclerotic lesions in end-stage renal disease patients.

Expression of an artificial Cl- channel in microperfused renal proximal tubules.

To better understand the process of fluid movement driven by Cl- conductance, a Cl- channel-forming peptide was delivered to the luminal membrane of microperfused rabbit renal proximal tubules. When the peptide (NK4-M2GlyR) was perfused, a significant new conductance was observed within 3 min and stabilized at 10 min. Alteration of the ion composition revealed it to be a Cl(-)-specific conductance. Reabsorption of Cl- (JCl) was increased by NK4-M2GlyR, but not by a scramble NK4-M2GlyR sequence, suggesting that the active peptide formed de novo Cl- channels in the luminal membrane of the perfused tubules. In the presence of the peptide, reabsorption of fluid (Jv) was dramatically increased and JNa and JCa were concomitantly increased. We propose that introduction of the new Cl- conductance in the luminal membrane leads to a coordinated efflux of water across the membrane and an increase in cation translocation via the paracellular pathway, resulting in an increase in Jv. This novel method could prove useful in characterizing mechanisms of fluid transport driven by Cl- gradients.

Different effects of St John's wort on the pharmacokinetics of simvastatin and pravastatin.

OBJECTIVE: St John's Wort, a widely used herbal product, is an inducer of CYP3A4 and it decreases blood concentrations of CYP3A4 substrates. The effects of St John's Wort on the pharmacokinetics of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors simvastatin (an inactive lactone pro-drug) and pravastatin were determined in this study. METHODS: Sixteen healthy male subjects (n = 8 in group 1 and n = 8 in group 2) took a St John's Wort caplet (300 mg) or matching placebo three times a day for 14 days in a double-blind, crossover study. On day 14, a single oral dose of 10 mg simvastatin and 20 mg pravastatin was given to subjects in group 1 and group 2, respectively. Blood samples were obtained during a 24-hour period after the administration of each drug. RESULTS: Repeated St John's Wort treatment tended to lower plasma simvastatin concentration and significantly (P <.05) lowered concentrations of simvastatin hydroxy acid, its active metabolite. The peak concentration in plasma (ratio, 0.72 of placebo) of simvastatin hydroxy acid tended to be decreased and its area under the plasma concentration-time curve between time zero and 24 hours after administration (ratio, 0.48 of placebo) was significantly decreased (P <.05) by St John's Wort. On the other hand, St John's Wort did not influence plasma pravastatin concentration. No significant differences were observed in the elimination half-life of simvastatin or pravastatin between the placebo and St John's Wort trials. CONCLUSIONS: This study showed that St John's Wort decreases plasma concentrations of simvastatin but not of pravastatin. Because simvastatin is extensively metabolized by CYP3A4 in the intestinal wall and liver, which are induced by St John's Wort, it is likely that this interaction is partly caused by the enhancement of the CYP3A4-mediated first-pass metabolism of simvastatin in the small intestine and liver.

Chronotherapy with active vitamin D3 in aged stroke-prone spontaneously hypertensive rats, a model of osteoporosis.

The chronotherapeutic effects of 1-alpha-(OH) vitamin D3, a pro-drug of 1,25(OH)2 vitamin D3 (1,25(OH)2D3), were evaluated by repeated dosing of the drug in aged stroke-prone spontaneously hypertensive male rats, a model of osteoporosis. Animals (7 months old) were kept in rooms with a 12-h light/dark cycle. Drug (0.5 microg/kg) or vehicle was given once daily at 2 or 14 h after lights on for 3 months. The severity of adverse effects such as body weight loss, hypercalcemia and hyperphosphatemia was significantly less when the drug was given at 14 h after lights on (14 HALO). Serum 1,25(OH)2 vitamin D3 concentrations of 2 h after lights on (2 HALO) group and 14 HALO group did not differ significantly after dosing. The decrease in parathyroid hormone (PTH) level 12 weeks after the start of the study was greater in the 14 HALO group than in the 2 HALO group. Urinary excretion of inorganic Ca and P in the 2 HALO group was greater than that in the 14 HALO group. Urinary excretion of deoxypyridiniline, an index of the bone resorption capacity of osteoclasts, was much suppressed in the 14 HALO group, suggesting that the efficacy of vitamin D3 for suppressing bone resorption might vary with the dosing time. The increase in bone density of both femurs, determined by dual-energy X-ray absorption at the end of the study, was greater in the 14 HALO group than in the 2 HALO group. This is the first study to show the dosing time-dependent efficacy and toxicity of active vitamin D3 in an animal model of osteoporosis. These results indicate that a chronopharmacological approach is beneficial for establishing a more effective and/or safer regimen of active vitamin D3 for the treatment of osteoporosis.

Dosing time-dependent effect of trandolapril on the prevention of cardiac hypertrophy in rats with aortic banding.

Trandolapril was given to male Wistar rats with aortic banding at 10 AM or 10 PM for 6 weeks to examine the influence of dosing time on the development of left ventricular mass (LVM). Aortic banding increased the LVM compared with the sham-operated animals (P<0.01). Trandolapril (1 mg/kg) at 10 AM reduced LVM (1.74+/-0.04 [S.E.M.] mg/g) more than the dosing at 10 PM (1.92+/-0.04 mg/g, P<0.05), suggesting that trandolapril has a dosing time-dependent effect in the prevention of cardiac hypertrophy in rats with aortic banding.

Effect of enalapril on diabetic nephropathy in OLETF rats: the role of an anti-oxidative action in its protective properties.

1. We have evaluated the effects of the angiotensin-converting enzyme inhibitor enalapril on renal function and oxidative status in the kidney of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of spontaneous onset of type 2 diabetes mellitus. 2. Enalapril (5 mg/kg) or vehicle (distilled water) was given once daily by gavage to 22-week-old male OLETF rats for 32 weeks. Long-Evans Tokushima Otsuka (LETO) rats, the control animals for OLETF rats, received vehicle alone (n = 10 in each group). 3. Enalapril attenuated the rise in blood pressure mildly, but significantly. Enalapril significantly blunted the development of proteinuria without a significant effect on creatinine clearance. At the end of the study period, the lipid peroxide content in the renal cortex was significantly increased in OLETF compared with LETO rats, in which enalapril had no effect on lipid peroxide content. Enalapril enhanced the activity of catalase in the renal cortex of OLETF rats, but had no effect on the activity of either superoxide dismutase or glutathione peroxidase. 4. These results suggest that oxidative stress may be involved in the development of nephropathy in type 2 diabetes. Enalapril exhibited renoprotective effects without changing lipid peroxides in the kidney, suggesting that the beneficial effects of the compound on diabetic renal damage in OLETF rats may not be mediated through an anti-oxidative action.

Protein kinase C and phosphatidylinositol 3-kinase independently contribute to P-glycoprotein-mediated drug secretion in the mouse proximal tubule.

We have recently reported that the apical membrane of the proximal tubule S2 segment from wild-type mice (WT mice) has the capacity for P-glycoprotein- (P-gp-) mediated drug efflux, whereas mice in which both mdr1a and mdr1b genes are disrupted (KO mice) do not. To examine the intracellular regulatory mechanisms of drug-transporting P-gp activity, we isolated and perfused proximal tubule S2 segments from WT and KO mice, and measured luminal efflux of the intracellular fluorescence of rhodamine 123, a fluorescent substrate of P-gp. The decay half-time of the intracellular fluorescence (t1/2) was regarded as an index of the drug-transporting P-gp activity. In the WT mice, the t1/2 was 36+/-5 s (n=35) during the basal period, and was significantly increased to 440+/-45 s by the luminal addition of verapamil (an inhibitor of P-gp). The addition of phorbol 12-myristate 13-acetate (PMA) [a protein kinase C (PKC) activator] to the bath increased t1/2, but 4alpha-phorbol (the inactive form of PMA) did not. The PMA-induced increase in t1/2 was further increased by the luminal addition of verapamil, and was partially inhibited by co-treatment with staurosporine or H-7 (inhibitors of PKC). Pretreatment with wortmannin or LY294002 [inhibitors of phosphatidylinositol 3-kinase (PI 3-kinase)] added to the bath also increased t1/2. The wortmannin- and LY294002-induced increase in t1/2 was also further increased by the luminal addition of verapamil. The effects of PMA on t1/2 were additive after cotreatment with wortmannin or LY294002. In the KO mice, t1/2 was 440+/-25 s (n=18) during the basal period, and was no longer affected by the addition of verapamil, staurosporine, H-7, wortmannin, or LY294002. Based on the use of pharmacological agents, we conclude that in the proximal tubule from WT mice, P-gp-mediated drug secretion occurs independently via PKC- and PI 3-kinase-dependent processes, whereas it is not present in KO mice, independently of PKC- and PI 3-kinase.

Shoulder stiffness: a common adverse effect of HMG-CoA reductase inhibitors in women?

Muscle symptoms are known as adverse effects of HMG-CoA reductase inhibitors but their incidence is reported to be low. We treated a case of shoulder stiffness related to such a drug, which prompted us to preliminarily survey its incidence. We found that nearly one-tenth of women (6/66) taking such drugs reported drug-related shoulder stiffness. Shoulder stiffness is a very common symptom, while drug-induced shoulder stiffness is generally unknown. Many cases involving such an adverse effect may thus be overlooked. We present 2 typical cases here.

Removal of digoxin by column for specific adsorption of beta(2)-microglobulin: a potential use for digoxin intoxication.

BACKGROUND: A beta(2)-microglobulin adsorption column used for the treatment of dialysis-related amyloidosis removes serum beta(2)-microglobulin by recognition of lipophilic residue in the protein. No data are available for the adsorption of the highly lipophilic drug digoxin. METHODS: In vivo clearance of digoxin with the beta(2)-microglobulin column was measured by a single use of the column in 8 patients receiving hemodialysis with a therapeutic level of digoxin. In vitro adsorption was evaluated by use of incubation with adsorbent of the column and digoxin or ranitidine, a hydrophilic drug. Clearance with the beta(2)-microglobulin column was further compared with that obtained by use of activated charcoal in the dogs intoxicated with digoxin. RESULTS: Digoxin concentration was reduced from 1.11 +/- 0.25 ng/mL to 0.57 +/- 0.15 ng/mL at 240 minutes after initiation of hemoperfusion with the column in the patients. Digoxin clearance with the beta(2)-microglobulin column was about 145 +/- 20 mL/min, with a blood flow rate of 160 to 220 mL/min (80% of plasma flow rate). Eighty-five percent of digoxin was adsorbed in vitro, and the capacity of the beta(2)-microglobulin column was not saturated until a toxic level was reached (50 ng/mL). This value was higher than that obtained with use of charcoal. In dogs with digoxin intoxication, digoxin clearance was 38.9 +/- 1.5 mL/min, with a blood flow rate of 50 mL/min (95% of plasma flow rate), which was almost twice as that achieved with charcoal. The degree of thrombocytopenia and leukopenia was small with use of the beta(2)-microglobulin column. CONCLUSION: These data suggested that the beta(2)-microglobulin column selectively adsorbs digoxin. This column is a promising tool for the treatment of digoxin intoxication, especially in patients undergoing hemodialysis.

Furosemide-probenecid interaction as a laboratory exercise for undergraduate education in clinical pharmacology.

OBJECTIVE: The aim of this study was to determine the easiness, reproducibility, and safety of a laboratory exercise for a drug interaction between furosemide and probenecid. METHODS: From 1995 to 1999 approximately 100 medical students participated in the exercise each year after they gave written informed consent. The students were randomly assigned to one of the three groups in a double-blind fashion: group 1, placebo plus 20 mg of furosemide; group 2, 250 mg of probenecid plus 20 mg of furosemide; and group 3, 1000 mg of probenecid plus 20 mg of furosemide. The students took probenecid or its placebo 1 hour before furosemide. Urine volume and urinary sodium excretion were measured for 3 hours after furosemide. At the end of the exercise in 1999, students responded to several questionnaires concerning the utility of furosemide. RESULTS: The entire course of the exercise was completed within half a day. The following findings were obtained every year. (1) Probenecid dose dependently blunted the diuretic effects of furosemide. (2) Time courses of the diuretic effects were altered by probenecid. Ten to twenty percent of the students had slight complaints but completed the exercise without any medications. Finally, more than 80% of the students considered the exercise to be useful. CONCLUSIONS: The data suggest that the exercise of the drug interaction between furosemide and probenecid is easy to perform, reproducible, and safe. Through the experience of the laboratory exercise, students will develop an attitude to assess and estimate potential drug interactions before they prescribe drugs.

Effect of prolonged nitric oxide synthesis inhibition on plasma fibrinogen concentration in rats.

We examined whether nitro-L-arginine-methyl ester (L-NAME) causes a sustained elevation in plasma fibrinogen concentration in rats. Oral dosing of L-NAME (100 mg/kg per day) for 7 days significantly raised plasma fibrinogen concentration in rats. The increase in plasma fibrinogen, however, returned to control levels by the treatment for more than 7 days, in spite of progressive hypertension. Candesartan failed to reverse the transient hyperfibrinogenemia, indicating that the rise in plasma fibrinogen may occur through the mechanisms other than angiotensin II receptor activation. These data suggest that a prolonged L-NAME treatment does not cause chronic hyperfibrinogenemia in rats.

Prevalence of genuine epilepsy among adult emergency patients with an episode of unconsciousness.

OBJECTIVE: Loss of consciousness (LOC) is caused by a variety of conditions including epileptic, cardiac, psychiatric, and autonomic disorders. We investigated the prevalence of presenting attacks of genuine epilepsy among patients of Emergency Department and Department of Cardiology evaluated for an episode of LOC with or without a convulsion. PATIENTS AND METHODS: We retrospectively studied 371 adults presenting to the Emergency Department and Department of Cardiology of our hospital from 1991 to 1999 with a chief complaint of an episode of LOC with or without a convulsion. Ages ranged from 15 to 78 years. Patients were free of severe chronic illnesses, drug abuse, and alcoholism. LOC was considered to represent genuine epilepsy either when the interictal electroencephalogram (EEG) showed epileptiform discharges in the absence of imaging abnormalities, or when both the EEG and imaging studies were unrevealing but one or more previous attacks had occurred and administration of an anticonvulsant prevented subsequent attacks. RESULTS: Patients included 302 patients without a convulsion, and 69 patients with a convulsion. Of the former, 14 subjects had epileptiform discharges on EEG, and three subjects had no epileptiform discharges but had three or four attacks of LOC that were abolished by anticonvulsant therapy. Of the 69 patients with a convulsion, seven had epileptiform discharges, and 12 had two to five attacks, no epileptiform discharges, and a response to anticonvulsant therapy. CONCLUSIONS: The prevalence of presenting attacks of genuine epilepsy in 371 adult patients with an episode of LOC was remarkably high (9.7%: 36 subjects).

Role of basolateral carbonic anhydrase in proximal tubular fluid and bicarbonate absorption.

Membrane-bound carbonic anhydrase (CA) is critical to renal acidification. The role of CA activity on the basolateral membrane of the proximal tubule has not been defined clearly. To investigate this issue in microperfused rabbit proximal straight tubules in vitro, we measured fluid and HCO(3)(-) absorption and cell pH before and after the extracellular CA inhibitor p-fluorobenzyl-aminobenzolamide was applied in the bath to inhibit only basolateral CA. This inhibitor was 1% as permeant as acetazolamide. Neutral dextran (2 g/dl, molecular mass 70,000) was used as a colloid to support fluid absorption because albumin could affect CO(2) diffusion and rheogenic HCO(3)(-) efflux. Indeed, dextran in the bath stimulated fluid absorption by 55% over albumin. Basolateral CA inhibition reduced fluid absorption ( approximately 30%) and markedly decreased HCO(3)(-) absorption ( approximately 60%), both reversible when CA was added to the bathing solution. In the presence of luminal CA inhibition, which reduced fluid ( approximately 16%) and HCO(3)(-) ( approximately 66%) absorption, inhibition of basolateral CA further decreased the absorption of fluid (to 74% of baseline) and HCO(3)(-) (to 22% of baseline). CA inhibition also alkalinized cell pH by approximately 0.2 units, suggesting the presence of an alkaline disequilibrium pH in the interspace, which would secondarily block HCO(3)(-) exit from the cell and thereby decrease luminal proton secretion (HCO(3)(-) absorption). These data clearly indicate that basolateral CA has an important role in mediating fluid and especially HCO(3)(-) absorption in the proximal straight tubule.

The effect of a Rho kinase inhibitor Y-27632 on superoxide production, aggregation and adhesion in human polymorphonuclear leukocytes.

We investigated the involvement of p160ROCK (a Rho-associated coiled coil-forming protein kinase), one of Rho kinases on superoxide anion production (O(2)(-) production), aggregation and adhesion of human polymorphonuclear leukocytes under physiological condition, using a selective p160ROCK inhibitor, (+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide (Y-27632). Y-27632 inhibited the O(2)(-) production stimulated by phorbol-12-myristate-13-acetate (PMA) in a dose-dependent manner. Stauroprorine blocked the PMA-induced O(2)(-) production while wortmannin did not. Y-27632 also inhibited the O(2)(-) production by guanosine 5'-O-(3-thiotriphosphate) (GTP(gamma)S) 100 microM. N-formyl-Met-Leu-Phe (fMLP)-induced O(2)(-) production was not influenced by Y-27632, but was inhibited by wortmannin. The enhanced O(2)(-) production by Ca-ionophore A23817 and thapsigargin was not inhibited by Y-27632. Y-27632 did not change the basal intracellular Ca(2+) concentration nor its elevation stimulated by fMLP. Polymorphonuclear leukocytes aggregation induced by PMA was dose-dependently decreased by Y-27632 while their aggregation stimulated by fMLP was enhanced by the agent. Polymorphonuclear leukocytes adhesion induced by PMA or fMLP was not influenced by Y-27632.These results suggest that p160ROCK is involved in the PMA-induced O(2)(-) production and aggregation in human polymorphonuclear leukocytes. This kinase might locate in downstream of protein kinase C in polymorphonuclear leukocytes.