Steroid administration after anaesthetic induction with etomidate does not reduce in-hospital mortality or cardiovascular morbidity after non-cardiac surgery.

BACKGROUND: We tested the primary hypothesis that corticosteroid administration after etomidate exposure reduces a composite of in-hospital mortality and cardiovascular morbidity after non-cardiac surgery. METHODS: We evaluated ASA physical status III and IV patients who had non-cardiac surgery with general anaesthesia at the Cleveland Clinic. Amongst 4275 patients in whom anaesthesia was induced with etomidate, 804 were also given steroid intraoperatively, mostly dexamethasone at a median dose of 6 mg. We successfully matched 582 steroid patients with 1023 non-steroid patients. The matched groups were compared on composite of in-hospital mortality and cardiovascular morbidity using a generalized-estimating-equation model. Secondly, the matched groups were compared on length of hospital stay using a Cox proportional hazard model, and were descriptively compared on intraoperative blood pressures using a standardized difference. RESULTS: There was no significant association between intraoperative steroid administration after anaesthetic induction with etomidate and the composite of in-hospital mortality or cardiovascular morbidity; the estimated common odds ratio across the two components of the composite was 0.86 [95% confidence interval (CI): 0.64, 1.16] for steroid vs non-steroid, P=0.33. The duration of postoperative hospitalisation was significantly shorter amongst steroid patients [median (Q1, Q3): 6 (3, 10) days] than non-steroid patients [7 (4, 11) days], with an estimated hazard ratio of 0.89 (0.80, 0.98) for steroid vs non-steroid, P=0.01. Intraoperative blood pressures were similar in steroid and non-steroid patients. CONCLUSIONS: Steroid administration after induction of anaesthesia with etomidate did not reduce mortality or cardiovascular morbidity.

Biomechanical evaluation of the phases during simulated endotracheal intubation (ETI): pilot study on the effect of different laryngoscopes.

Endotracheal Intubation (ETI) is a common airway procedure used to connect the larynx and the lungs through a windpipe in patients under emergency situations. The process is carried out by a laryngoscope inserted into the mouth, used to help doctors in visualizing the glottis and inserting the tube. Currently, very few studies on objective evaluation of the biomechanics of the doctors during the procedure have been done. Additionally, these studies have been concentrated only on the overall performance analysis, without any segmentation, with a consequent loss of important information. In this paper, the authors present a preliminary study on a methodology to objectively evaluate and segment the biomechanical performance of doctors during the ETI, using surface electromyography and inertial measurement units. In particular, the validation has been performed by comparing three kinds of laryngoscopes involving an expert doctor. Finally, results are presented and commented.

Origin of automaticity and neural regulation of peristalsis in the gastrointestinal tract of Aplysia and Lymnaea. Short communication.

We examined whether the enteric nervous system (ENS) is capable of controlling autonomous peristalsis, which occurs in the crop of Aplysia as well as in the esophagus of Lymnaea. Interestingly, "pacemaker neurons", which lead peristaltic rhythm, were found in the gizzard in Aplysia and in the crop in Lymnaea; both of these structures are located distal to the regions exhibiting peristalsis. Thus, the bursting activity of the ENS first occurred in lower regions and then progressed in an ascending direction (i.e. in the opposite direction of peristalsis). The two species are thought to differ in terms of the mechanisms involved in producing peristalsis.

Applicability of DPI formulations for novel neurokinin receptor antagonist.

A novel triple neurokinin receptor antagonist (TNRA) could have pharmaceutical efficacy for asthma and/or chronic obstructive pulmonary disease. TNRA is potentially developed as inhalation medicine. The aim of this investigation was to evaluate the applicability of dry powder inhaler (DPI) formulation for TNRA. DPI formulation containing lactose was used for this feasibility study. Mechanofusion process for surface modification was applied on lactose particles to prepare four different DPI formulations. The mixture of TNRA and lactose was administered to rats intratracheally using an insufflator. The deposition pattern and blood concentration profile of TNRA were evaluated. Although there was no significant difference in deposition on deep lungs between the four formulations, DPI formulations containing mechanofusion-processed lactose showed longer T(max) and t(1/2) and higher AUC(0-infinity) and MRT compared to that containing intact lactose. On the other hand, the contact angle measurement showed that the mechanofusion process decreased the polar part of the surface energy of the lactose. Therefore, the prolongation of the wetting of the formulated powder mixture seemed to delay the dissolution of TNRA deposited in respiratory tract. It was concluded that DPI formulation containing mechanofusion-processed lactose could be suitable for inhalation of TNRA.

Fe-sapphire and C-Fe-sapphire interactions and their effect on the growth of single-walled carbon nanotubes by chemical vapor deposition.

We previously reported that the quantity of single-walled carbon nanotubes grown on Fe-coated sapphire by chemical vapor deposition depended on the crystallographic faces of sapphires. In this report, we show that the interaction of Fe, sapphire, and carbon depended on the sapphire faces. We deduce that the quantity of Fe available to catalyze the growth of single-walled carbon nanotubes was suppressed by the formation of Fe-Al alloys and whether the Fe-Al alloys were formed on Fe-coated sapphire or not depended on the sapphire-surface structure.

The relation between single/double or repeated tea catechin ingestions and plasma antioxidant activity in humans.

OBJECTIVE: The purpose of this study was to investigate the effects of single/double or repeated intake of a normal amount of tea catechin on plasma catechin concentrations and antioxidant activity in young women. DESIGN: First, after an overnight fast, five healthy subjects were given water or single/double dose(s) of tea polyphenol extract (164 mg tea catechins containing 61% epigallocatechin gallate in 190 ml water). Blood samples were taken before and 30, 60 and 180 min after the ingestion. Second, 16 healthy subjects ingested the tea polyphenol extract three times a day at mealtimes for 7 days followed by withdrawal of tea polyphenol extract for 7 days. Blood samples were taken before and after ingestion, and 7 days after the withdrawal of tea catechin. Subjects were prohibited from drinking any beverages containing polyphenols or antioxidant supplements during the study period. Catechin and other antioxidant concentrations in the plasma were measured, and changes in antioxidant activity were evaluated by ferric reducing ability of plasma assay. RESULTS: Single/double ingestion of tea polyphenol extract did not cause an increase in the antioxidant activity. There was no also change in antioxidant activity after the ingestion of tea polyphenol extract for 7 days. Plasma-free epigallocatechin gallate concentration remained at the pre-study level; however, the plasma FRAP value decreased significantly at 7 days after the withdrawal of tea polyphenol extract. Decreases in endogenous antioxidants in the plasma, including vitamin C and bilirubin, were also observed 7 days after withdrawal of tea polyphenol. CONCLUSIONS: The results suggest that continuous daily intake of tea catechins affects the concentrations of endogenous antioxidants in the plasma and has the potential to maintain total antioxidant activity.

Possible involvement of p38 mitogen-activated protein kinase in decidual function in parturition.

We designed the present study to elucidate the molecular mechanism for parturition, focusing on p38 mitogen-activated protein kinase (p38). The kinase activity of p38 in mouse uterus was gestation stage-dependent, and was markedly increased on day 19 of gestation and during labor. Immunohistochemical examination with anti-phospho p38 antibody revealed that activated p38 was predominantly localized in decidual stromal cells stained with anti-prolactin antibody. In human primary cultured decidual cells, a p38 inhibitor, SB202190, significantly inhibited both prostaglandin F(2alpha) production and COX-2 expression induced by stimulation with IL-1beta. These results suggest that the p38 signaling pathway is involved in decidual function at the late stage of gestation and may contribute to parturition.

The anxiolytic effects of the 5-hydroxytryptamine-1A agonist tandospirone before otolaryngologic surgery.

UNLABELLED: We studied 160 ASA I or II patients undergoing elective otolaryngologic surgery in order to compare the anxiolytic effects of a novel 5-hydroxytryptamine-1A agonist, tandospirone, with diazepam. To monitor preoperative anxiety, the following variables were used: systolic and diastolic arterial pressure, heart rate, and the state anxiety score yielded by the Spielberger State-Trait Anxiety Inventory. We performed pretreatment evaluation on the day before surgery and posttreatment examination immediately after entry into the operating room. In a double-blinded, randomized design, four groups of 40 patients each received one of the following oral medications 90 min before entry into the operating room: 1) tandospirone 10 mg (T10 group); 2) tandospirone 30 mg (T30 group); 3) diazepam 10 mg (D group); or 4) placebo (P group). After premedication, the State-Trait Anxiety Inventory state anxiety decreased in the T10 (P < 0.02), T30 (P < 0.02), and D groups (P < 0.001), but it increased in the P group (P < 0.001). Tandospirone, 10 and 30 mg, safely reduced preoperative anxiety to a similar extent as oral diazepam 10 mg in patients undergoing elective otolaryngologic surgery. IMPLICATIONS: Oral tandospirone reduces preoperative anxiety to a similar extent as oral diazepam in patients undergoing elective otolaryngologic surgery. This finding implies that tandospirone can be used as an oral premedicant drug for relieving anxiety before surgery.

Hydrolysis of conjugated steroids by the combined use of beta-glucuronidase preparations from helix pomatia and ampullaria: determination of urinary cortisol and its metabolites.

This study describes the enzymatic hydrolysis of urinary conjugates of cortisol, cortisone, tetrahydrocortisol, allotetrahydrocortisol, and tetrahydrocortisone with beta-glucuronidase preparations from Helix pomatia and Ampullaria. The objective of the present studies was to find optimal hydrolysis conditions for these conjugated steroids. Assay of the isolated steroids was carried out by GC-MS using deuterium-labeled compounds as internal standards. The allotetrahydrocortisol conjugate was clearly the hardest to hydrolyze with enzyme from Helix pomatia and required increased enzyme concentration and prolonged incubation. Hydrolysis of a urine sample for 2.0 h with the simultaneous use of 3400 units/ml Ampullaria and 5400 units/ml Helix pomatia enzymes in 0.5 M acetate buffer at 55 degrees C achieved more complete cleavage of the urinary conjugates of the five steroids examined. It is thus advantageous to use the Ampullaria and Helix pomatia enzymes in combination to obtain the highest yield in the urinary corticosteroid assay.

Differences in cell kinetic changes among renal cancer cell lines treated with interferon-alpha.

BACKGROUND: Interferon (IFN)-alpha shows certain clinical effects on the treatment of renal cell carcinoma. The purpose of the present study was to investigate its direct effects and to compare the responses among different human renal cancer cell lines. METHODS: Three cell lines, ACHN, RCC10RGB and OS-RC-2, were incubated with IFN-alpha and evaluated using MTT assay for cell proliferation and two-color flow cytometry for cell-cycle-specific cyclin expressions coupled with DNA ploidy analysis. RESULTS: Interferon-alpha inhibited cell proliferation and caused cell accumulation at S and G2/M phases. However, IFN-alpha induced no significant change in cyclins D1, E, A or B1 expression. Interestingly, cell kinetic changes caused by IFN-alpha were different among cell lines. Cell proliferation was suppressed most in ACHN, then RCC10RGB and least in OS-RC-2. Comparing DNA histograms, ACHN showed distinct increase of G2/M cells associated with elevation of late S cells. RCC10RGB showed a predominant increase of whole S cells accompanied with a slight increase of G2/M. OS-RC-2 showed a modest increase of S cells with a little change of G2/M cells. Chronological observation revealed that S-phase increase and proliferative inhibition appeared on day 1 and day 3, respectively, in ACHN and RCC10RGB, and on day 5 in OS-RC-2. CONCLUSIONS: Interferon-alpha induced substantial cell kinetic interference directly in the tested human renal carcinoma cell lines. The degree of change was different according to the nature of the cell line. It may partly indicate the variety of the efficacy of IFN-alpha treatment against renal cancers.

Synthesis and characterization of HPMA copolymer-aminopropylgeldanamycin conjugates.

Geldanamycin (GDM) is a benzoquinone ansamycin antibiotic with anticancer activity. The use of drug delivery systems based on N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers containing lysosomally degradable oligopeptide (GFLG) spacers results in an increased therapeutic efficacy of anticancer drugs. The objective of this study was to synthesize HPMA copolymer-GDM conjugates with anticancer activity and reduced toxic side-effect of the compound. 17-(3-Aminopropylamino)-17-demethoxygeldanamycin (AP-GDM) was synthesized and converted into a polymerizable GDM derivative, N-methacryloylglycylphenylalanylglycyl-17-(3-aminopropylamino)-17-demethoxygeldanamycin [MA-GFLG-(AP-GDM)]. The structures of AP-GDM and MA-GFLG-(AP-GDM) were validated by mass spectroscopy, elemental analysis, and two-dimensional nuclear magnetic resonance. MA-GFLG-(AP-GDM) was copolymerized with HPMA and N-methacryloyglycylglycine p-nitrophenylester by radical precipitation polymerization. Water-soluble HPMA copolymer-AP-GDM conjugates (M(r)=16 kDa) were obtained. Monoclonal antibody OV-TL16, which recognizes the OA-3 antigen expressed on the OVCAR-3 human ovarian carcinoma cell line, was optionally attached to the HPMA copolymer-AP-GDM conjugate. Cytotoxicity of polymer-bound AP-GDM (both targeted and non-targeted) was determined using OVCAR-3 and another human ovarian carcinoma cell line, A2780. The HPMA copolymer-AP-GDM conjugate was cytotoxic toward A2780 cells. Attachment of OV-TL16 antibody enhanced cytotoxicity of the conjugate toward OVCAR-3 cells.

Determination of rutin in human plasma by high-performance liquid chromatography utilizing solid-phase extraction and ultraviolet detection.

An HPLC method for determining a flavonol glycoside, rutin, in human plasma is presented for application to the pharmacokinetic study. Isocratic reversed-phase HPLC was employed for the quantitative analysis by using kaempferol-3-rutinoside as an internal standard. Solid-phase extraction was performed on an Oasis MAX cartridge possessing reversed-phase and anion-exchange functions (recovery, approximately 80%). The HPLC assay was carried out using a Luna ODS-2 column (150 x 2.1 mm I.D., 5 microm particle size). The mobile phase was acetonitrile-10 mM ammonium acetate solution containing 0.3 mM EDTA-glacial acetic acid (16.5:82.5:1, v/v, pH 3.8). The flow-rate was 0.3 ml/min. The detection wavelength was set at 370 nm. Calibration of the overall analytical procedure gave a linear signal (r>0.9999) over a concentration range of 3-1,000 ng/ml of rutin in plasma. The lower limit of quantification was ca. 5 ng/ml of rutin in plasma. The detection limit (defined as signal-to-noise ratio of about 3) was approximately 0.75 ng/ml. A preliminary experiment to investigate the plasma concentration of rutin after oral administration of 500 mg of rutin to a healthy volunteer demonstrated that the present method was suitable for determining rutin in human plasma.

Improved synthesis and evaluation of 17-substituted aminoalkylgeldanamycin derivatives applicable to drug delivery systems.

The 17-methoxy group of geldanamycin was substituted with 1,3-diaminopropane and 1,3-diamino-2-hydroxypropane to introduce a primary amino group useful for conjugation with targeting moieties and drug carriers. We have developed a procedure that has provided improved yield and reproducibility of the syntheses. Both geldanamycin derivatives demonstrated antiproliferative activity towards the human ovarian carcinoma cell line, A2780.

Effects of calmodulin antagonist (W-7) on phorbol ester (PMA)-induced contractile response in isolated rat aorta.

The aim of this study was to investigate effects of calmodulin antagonist (W-7) on the contractile response of the rat aorta induced by activation of protein kinase C (PKC) by phorbol ester. Phorbol 12-myristate 13-acetate (PMA) produced biphasic contraction i.e., a sustained contraction (initial contraction) and 17.9 +/- 1.7 min later, this progressively developed contraction was changed to a delayed contraction superimposed on the initial contraction. The delayed contraction was completely inhibited by treatment with nicardipine. The onset of the delayed contraction was significantly delayed by treatment with W-7, whereas same concentration of W-7 showed a weak relaxant effect (10%) on the PMA-induced maximal contraction of aorta. Higher concentration of W-7 strongly inhibited PMA-induced sustained contraction. These results suggest that PMA-induced biphasic contractile response may be regulated by calmodulin.

Kinetics of intramolecular acyl migration of 1beta-O-acyl glucuronides of (R)- and (S)-2-phenylpropionic acids.

The stereoselective acyl migration of diastereomeric 1beta-O-acyl glucuronides of (R)- and (S)-2-phenylpropionic acid [(R)-1PG and (S)-IPG, respectively] in phosphate buffer (pH 7.4) at 310K was investigated using HPLC. The disappearance of (R)-1PG was faster than that of (S)-1PG according to pseudo first-order kinetics. A kinetic model describing the degradation reactions was constructed. The rate constant for acyl migration from the 1beta-O-isomer to the 2-O-acyl isomer (k12) was about one order magnitude larger than that for hydrolysis from 1beta-O-acyl isomer to aglycone (k10). The k12 of (R)-IPG (0.377 +/- 0.005 h(-1)) was about two times larger than that of (S)-IPG (0.184 +/- 0.003 h(-1)). The results indicated that the stereoselectivity in the degradation of 1PG was apparently governed by the acyl migration from 1-isomer to 2-isomer. The kinetic parameters for acyl migration from 1-isomer to 2-isomer were estimated from temperature-dependent experiments using the transition state theory. The value of the free energy of activation at 310 K for (R)-1PG (99.67 kJ/mol) was smaller than that of (S)-IPG (101.60kJ/mol), suggesting that (R)-IPG showed thermodynamically higher reactivity in acyl migration than (S)-1PG.

Glucose-induced hyperproliferation of cultured rat aortic smooth muscle cells through polyol pathway hyperactivity.

AIMS/HYPOTHESIS: The protein kinase C (PKC), platelet-derived growth factor (PDGF) and polyol pathway play important parts in the hyperproliferation of smooth muscle cells, a characteristic feature of diabetic macroangiopathy. The precise mechanism, however, remains unclear. This study investigated the relation between polyol pathway, protein kinase C and platelet-derived growth factor in the development of diabetic macroangiopathy. METHODS: Smooth muscle cells were cultured with 5.5 or 20 mmol/l glucose with or without an aldose reductase inhibitor, epalrestat, or a PKC-beta specific inhibitor, LY333531. Protein kinase C activities, the expression of PKC-beta II isoform and PDGF-beta receptor protein, free cytosolic NAD+:NADH ratio, the contents of reduced glutathione, and proliferation activities were measured. RESULTS: Smooth muscle cells cultured with 20 mmol/l glucose showed statistically significant increases in protein kinase C activities, the expression of PKC-beta II isoform and PDGF-beta receptor protein, and proliferation activities, compared with smooth muscle cells cultured with 5.5 mmol/l glucose. Although epalrestat and LY333531 inhibited protein kinase C activation induced by glucose to the same degree, the effects of epalrestat on proliferation activities and expression of the PDGF-beta receptor were more prominent than those of LY333531. Epalrestat improved the glucose-induced decrease in free cytosolic NAD+:NADH ratio and reduced glutathione content, but LY333531 did not. The increased expression of membranous PKC-beta II isoform was normalized by epalrestat. CONCLUSION/INTERPRETATION: These observations suggest that polyol pathway hyperactivity contributes to the development of diabetic macroangiopathy through protein kinase C, PDGF-beta receptor, and oxidative stress, and that an aldose reductase inhibitor has a therapeutic value for this complication.

[A case of cardiac arrest with coronary artery spasm during lumbar epidural anesthesia].

A 61-year-old man underwent arthroscopic surgery for internal derangement of the knee joint under epidural anesthesia. Epidural catheterization was performed at the L 2-3 interspace. Operation was started with 10 ml of 1.5% lidocaine. Then 12 ml of 0.375% bupivacaine was added to epidural space. Twenty minutes thereafter, electrocardiogram demonstrated marked elevation of ST segment and atrio-ventricular dissociation, followed by cardiac arrest. Cardiopulmonary resuscitation was started immediately and after 25 minutes normal sinus rhythm was restored. The patient recovered with no neurological sequelae. Coronary angiogram examination was performed but no significant stenosis of coronary artery was observed. Coronary artery spasm caused by lumbar epidural anesthesia was suspected.

[Analyses of factors preventing returning home in elderly patients on dialysis].

A significant number of elderly patients who begin dialysis are not able to return home even after attaining stable dialysis. The aim of the present study is to clarify the factors preventing returning home. Patients aged over 60 years who had newly started dialysis (103 cases) were studied. These were 58 men and 45 women. The age was 73 +/- 7 years (mean +/- standard deviation). In each patient, the cause of renal failure (non-diabetes/diabetes), nutritional state, complications, ambulation, cognitive function, urgency of the initiation into dialysis therapy, occurrence of access failure, presence or absence of the partner, presence or absence of members of the younger generation living in the same house, and the outcome (returning home or prolonged hospitalization) were surveyed. Of the 103 patients, 80 could return home, and 23 could not. First, we investigated the influence of the differences in each factor on the outcome. The subjects were divided into two groups by two categories in each factor. The numbers of patients who could not return home was calculated respectively. Comparisons were carried out by the chi 2 test. Statistically significant factors were ambulation (p < 0.0001), cognitive function (p < 0.0001), and cause of renal failure (p: 0.049). Multivariant logistic regression analysis was also performed using back-ground factors as explanatory variables and the outcome as a dependent variable. The factors presented by the nominal scale were converted to dummy variables. Statistically significant factors were ambulation (p < 0.0001), cognitive function (p: 0.001), and presence or absence of a partner (p: 0.012). Inability to walk, impaired cognitive function, and absence of a partner were the factors preventing returning home.

Epalrestat, an aldose reductase ihibitor, reduces the levels of Nepsilon-(carboxymethyl)lysine protein adducts and their precursors in erythrocytes from diabetic patients.

OBJECTIVE: To clarify the role of the polyol pathway in the intracellular formation of advanced glycation end products in human tissues, we examined the effects of epalrestat, an aldose reductase inhibitor, on the level of Nepsilon-(carboxymethyl)lysine (CML) along with 3-deoxyglucosone (3-DG) and triosephosphates in erythrocytes from diabetic patients. Plasma thiobarbituric acid-reactive substances (TBARS) were also determined as indicators of oxidative stress. RESEARCH DESIGN AND METHODS: Blood samples were collected from 12 nondiabetic volunteers, 38 untreated type 2 diabetic patients, and 16 type 2 diabetic patients who had been treated with 150 mg epalrestat/day. Blood samples were also collected from 14 of the untreated type 2 diabetic patients before and after the administration of epalrestat for 2 months. The amount of erythrocyte CML was determined by a competitive enzyme-linked immunosorbent assay, and 3-DG was measured by high-performance liquid chromatography RESULTS: In diabetic patients not treated with epalrestat, the erythrocyte CML level was significantly elevated above levels seen in nondiabetic individuals (49.9 +/- 5.0 vs. 31.0 +/- 5.2 U/g protein, P < 0.05) and was significantly lower in patients receiving epalrestat (33.1 +/- 3.8 U/g protein, P < 0.05). Similar results were observed with 3-DG. The treatment of patients with epalrestat for 2 months significantly lowered the level of erythrocyte CML (46.2 +/- 5.6 at baseline vs. 34.4 +/- 5.0 U/g protein, P < 0.01) along with erythrocyte 3-DG (P < 0.05), triosephosphates (P < 0.05), fructose (P < 0.05), sorbitol (P < 0.05), and plasma TBARS (P < 0.05) without changes in plasma glucose and HbA(1c) levels. A positive correlation was evident between the erythrocyte CML and sorbitol (r = 0.49, P < 0.01) or fructose (r = 0.40, P < 0.05) levels in diabetic patients. CONCLUSIONS: The results indicate that epalrestat administration lowers CML and associated variables and that polyol metabolites are correlated with CML in the erythrocytes of diabetic patients. The observed results suggest that aldose reductase activity may play a substantial role in the intracellular formation of CML in the mediation of reactive intermediate metabolites and oxidative stress.

Aldose reductase inhibition prevents glucose-induced apoptosis in cultured bovine retinal microvascular pericytes.

The pathogenesis of pericyte loss, an initial deficit in the early stage of diabetic retinopathy, remains unclear. Polyol pathway hyperactivity has been implicated in the pathogenesis of diabetic retinopathy, and recent studies have suggested that apoptosis may be involved in pericyte loss. The present study was conducted to investigate whether high glucose induces apoptosis in cultured bovine retinal pericytes. The effect of an aldose reductase inhibitor, SNK-860, was also examined. After a 5 day incubation with various concentrations of glucose (5.5-40 m M) in the presence or absence of SNK-860, the cell viability and the percentages of dead cells were measured, and staining with the TUNEL method and Hoechst 33342, and DNA electrophoresis were performed. High glucose reduced the viability and increased the percentages of dead cells. TUNEL-positive cells were observed in pericytes under high glucose, but not in those under 5.5 m M glucose. In the staining of nuclei with Hoechst 33342, the percentage of apoptotic cells in total cells counted under high glucose was higher than that under 5.5 m M glucose. DNA electrophoresis of pericytes cultured with high glucose demonstrated a 'ladder pattern'. Hyperosmolarity also induced apoptosis in pericytes, but less than that by high glucose. SNK-860 inhibited the glucose-induced apoptosis in pericytes. These observations suggest that the pericyte loss in diabetic retinopathy involves an apoptotic process, and that the polyol pathway hyperactivity plays an important role in inducing apoptosis in pericytes by high glucose.