Peroxovanadium-mediated protection against murine leishmaniasis: role of the modulation of nitric oxide

The phosphotyrosine phosphatase inhibitor bpV(phen) has the ability to markedly decrease the progression of leishmaniasis in vivo. Here, we have identified the mechanisms that are responsible for this protective effect. We report that two potent peroxovanadium (pV) compounds, bpV(phen) and bpV(pic), control progression of leishmaniasis in a similar manner by modulating NO-dependent microbicidal action. We observed that their injection can rapidly and transiently induce the expression of inducible NO synthase (iNOS) in livers of mice and enhance circulating nitrate levels. Treatment of mice with bpV(phen) or bpV(pic) completely controlled progression of leishmaniasis in an NO-dependent manner, since inhibition of iNOS with aminoguanidine completely reversed this pV-mediated protection. This NO-dependent pV-mediated protection was further demonstrated by the incapacity of bpV(phen)-treated Nramp-/-, iNOS-/- mutant mice to control Leishmania major infection. Using an air pouch model, we showed that bpV(phen) can strongly modulate secretion of L. major-induced pro-inflammatory molecules and neutrophil recruitment. In addition, we observed that bpV(phen) per se can strongly induce the expression of Th1 type cytokines over Th2 in spleens of animals. Overall, this study has allowed us to establish the in vivo functional and immunological events involved in pV-mediated protective mechanism against leishmaniasis and that NO plays a pivotal role in this process.     

Campylobacter fetus translocation across Caco-2 cell monolayers

Campylobacter fetus is a recognized pathogen of cattle and sheep, though human infection has also been reported. Ingestion of contaminated food or water is a proposed route of transmission for both humans and animals. The subsequent detection of the organism from extra-intestinal and systemic locations implies an ability to translocate across epithelial barriers. To determine how C. fetus disseminates from the intestine, Caco-2 cells cultured on porous membrane supports, were used as model intestinal epithelial cell monolayers. C. fetus was found to translocate equally well in both apical-to-basolateral and basolateral-to-apical directions for up to 24 h without altering Caco-2 cell monolayer permeability as assessed by transepithelial resistance and absence of paracellular diffusion of FITC-inulin. Using modified antibiotic protection assays, C. fetus was also observed to invade and subsequently egress from Caco-2 cells. Caco-2 cell invasion and translocation occurred independently of C. fetus S layer expression. Scanning and transmission electron microscopy revealed the presence of C. fetus associated with both apical and basal surfaces as well as in intracellular locations. C. fetus was, however, never observed in paracellular locations nor associated with Caco-2 cells junctions. Neither C. fetus invasion nor translocation across Caco-2 cell monolayers was impacted by latrunculin A, though translocation was enhanced in the presence of cytochalasin D which disrupted tight junctions. Tubulin cytoskeleton disrupting agents, colchicine and vinblastine, did inhibit C. fetus translocation though entry into Caco-2 cells remained unaffected. Together, translocation without disrupting monolayer integrity, invasion and egression from Caco-2 cells, electron microscopy observations and the requirement of a functional tubulin cytoskeleton for translocation, support a transcellular mechanism of C. fetus translocation across Caco-2 cell monolayers. The ability to invade and subsequently egress would contribute to establishment of an infecting C. fetus population in the host, while the demonstrated ability to translocate across model intestinal epithelial barriers accounts for the observed in vivo recovery of C. fetus from extra-intestinal locations.     

Interactions of Yersinia enterocolitica with polarized human intestinal Caco-2 cells

The in vitro interactions of Yersinia enterocolitica, Salmonella typhimurium and Escherichia coli with polarized human colonie carcinoma (Caco-2) cells are described. Invasion of a confluent Caco-2 cell monolayer by Yersinia and Salmonella took place within 4 h after contact, which was in marked contrast to E. coli which did not invade Caco-2 cells. Cytoplasmic extrusions developed on the apical membrane and indicated the site of entrance of bacteria into the Caco-2 cells. Intracellular Yersinia and Salmonella were surrounded by a vacuolar membrane. Single as well as multiple bacteria were enclosed within a single vacuole. At 6 h after contact some of the intracellular yersiniae were found free in the cytoplasm. Furthermore, morphological signs of degeneration of Caco-2 cells such as vacuolization and autophagy were observed. Caco-2 cells infected with Salmonella also showed degenerative changes but the salmonellae resided within membranebound vacuoles in contrast to Yersinia. These observations are in contrast to those described for the invasion of other cell lines (not derived from intestinal epithelium) by Yersinia and may reflect more closely the interactions between Yersinia and the intestinal epithelium during gastrointestinal infection.     

Age dependence of skin autofluorescence

The nontryptophane intrinsic fluorescence of finger pad skin was studied in men aged 20–70 years in order to evaluate the possibility of using this parameter as a biomarker of aging. Linear correlation coefficients (r) between the fluorescence intensity and age varied from 0.50 to 0.66 for various skin sites. Age dependence of the mean value of fluorescence (F) measured on 4 fingers can be approximated by a second-degree polynomial:F=2.82−0.083T+0.0014T ² (r ₁=0.64,r ₂=0.71), whereT is chronological age in years. The proposed measurement of skin autofluorescence is a simple, noninvasive, rapid test for evaluating the aging of the skin in subjects over 40 with a high age-related determination (r ²=0.5). Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 3, pp. 351–353, March, 1999     

Small transepithelial osmotic gradients affect apical sodium permeability in frog skin

The aim of the present study was to investigate the effects of small, unilateral changes in solution osmolarity on active sodium transport and cellular electrophysiological parameters in frog skin. The active sodium transport across the skin was measured as the amiloride-sensitive short-circuit current (I _sc) and cellular potential was monitored with microelectrodes, while small (±20 mOsm) osmotic gradients were imposed on the skin. Increasing the osmolarity of the apical bathing solution (or decresing the osmolarity of the basolateral solution) increased I _SC, lowered tissue resistance (R), depolarized the cellular potential and decreased the fractional resistance of the apical membrane, which indicates an increased apical sodium permeability. Conversely, a similar increase in basolateral osmolarity (or a decrease in apical osmolarity) lowered the I _sc, increased R, hyperpolarized the cells and increased the fractional resistance of the apical membrane, indicating a decrease in apical sodium permeability. The results indicate that the osmotic gradient across the skin, rather than solution osmolarity as such, is responsible for the observed changes in I _sc and apical sodium permeability after small osmotic perturbations.     

A minD mutant of enterohemorrhagic E. coli O157:H7 has reduced adherence to human epithelial cells

Adherence to epithelial cells is a prerequisite for intestinal colonization by the bacterial pathogen, enterohemorrhagic Escherichia coli (EHEC). The deletion of minD, a cell division gene, in EHEC caused reduced adherence to human epithelioid cervical carcinoma (HeLa) and human colonic adenocarcinoma (Caco-2) cells as compared to wild-type. The minD mutant formed minicells and filaments owing to aberrant cytokinesis. Moreover, its ability to form microcolonies as typically seen in the co-cultures of wild-type with Caco-2 cells, was abolished. In conclusion, the present study highlights the importance of minD in regards to EHEC adherence to human epithelial cells.     

Enteropathogenic Escherichia coli Virulence Genes Encoding Secreted Signalling Proteins Are Essential for Modulation of Caco-2 Cell Electrolyte Transport

The pathophysiology of enteropathogenic Escherichia coli (EPEC) diarrhea remains uncertain. In vitro, EPEC stimulates a rapid increase in short-circuit current (I_sc) across Caco-2 cell monolayers coincident with intimate attaching and effacing (A/E) bacterial adhesion. This study has examined the roles of specific EPEC virulence proteins in this I_sc response. EPEC genes encoding EspA, EspB, and EspD, essential for signal transduction in host cells and A/E activity, were also required for modulation of Caco-2 electrolyte transport.     

Complexation hydrogels for oral protein delivery: an in vitro assessment of the insulin transport-enhancing effects following dissolution in simulated digestive fluids

The insulin-transport enhancing effects of a pH-sensitive poly((methacrylic acid)-grafted-poly(ethylene glycol)) hydrogel system were studied using Caco-2 monolayers as an in vitro model of intestinal transport. Further, the ability of the hydrogel system to protect entrapped proteins through the upper gastrointestinal tract via digestion in simulated gastric and simulated intestinal fluids with digestive enzymes was confirmed. Caco-2 cell monolayers were exposed to a series of formulations including insulin alone, the polymer in insulin solution, insulin-loaded polymer (ILP) and ILP previously subjected to simulated digestive fluids with enzymes. These studies demonstrated greatly increased insulin transport for the ILP samples when compared with insulin alone and insulin in the presence of polymer, P _app = 12.7 × 10^?8 cm/s and 6.61 × 10^?8 cm/s versus 0.07 × 10^?8 cm/s and 0.06 × 10^?8 cm/s, respectively. While enhanced transport with the ILP was observed, the largest changes in TEER values did not coincide with the highest amounts of insulin transport, this suggests that the paracellular route may not be the sole mechanism of transport. Further, as the Caco-2 cell line has been demonstrated to possess the insulin receptor, active transport or a mixed mechanism cannot be ruled out.     

Skin tests, T cell responses and self-reported symptoms in children with allergic rhinitis and asthma due to house dust mite allergy

Background In allergic responses, a distinction is made between an early-phase response, several minutes after allergen exposure, and a late-phase response after several hours. During the late phase, eosinophils and T cells infiltrate the mucosa and play an important role in inflammation. Objective The aim of this study was to examine the relationship between allergen-induced late-phase skin responses and in vitro T cell reactivity. In addition, the relationship between allergen-induced skin or T cell responses and the severity of self-reported symptoms was studied in children with house dust mite allergy. Methods A total of 59 house dust mite-allergic children (6–18 years) were recruited in general practice. These children or their parents rated their nasal and asthma symptoms on diary cards during 1 month. Allergen skin tests were performed and read after 15 min (early phase) and 6 h (late phase). Allergen-specific T cell proliferation was determined, and Th2 cytokine (IL-5 and IL-13) secretion was analysed. Results The size of the late-phase skin response correlated with in vitro T cell proliferation (r_s=0.38, P=0.003) but not with Th2 cytokine secretion (r_s=0.16, P=0.2 for both IL-5 and IL-13). Moreover, the late-phase skin response and T cell proliferation correlated with asthma symptoms (r_s=0.30, P=0.02 for skin response and r_s=0.28, P=0.03 for T cell proliferation) but not with nasal symptoms (r_s=0.19, P=0.15 for skin response and r_s=0.09, P=0.52 for T cell proliferation). The early-phase skin response correlated with the nasal symptom score (r_s=0.34, P=0.01) but not with asthma symptom scores (r_s<0.005, P=0.97). Conclusion In this study, the late-phase skin test response correlated with in vitro T cell proliferation but not with Th2 cytokine secretion. We found weak or no correlations between late-phase skin responses and symptoms of asthma or rhinitis in children with house dust mite allergy. This suggests that late-phase skin responses reflect certain T cell properties but are of limited value for the evaluation of airway symptoms in atopic children.     

Hepatocyte growth factor stimulates invasion across reconstituted basement membranes by a new human small intestinal cell line

Hepatocyte growth factor/scatter factor (HGF/SF) is a protein growth factor whose pleiotropic effects on epithelial cells include the stimulation of motility, mitosis and tubulogenesis. These responses are mediated by the cell surface tyrosine kinase receptor c-met. Because both the cytokine and receptor are found in the gastrointestinal tract, we have studied the effects of HGF/SF on transformed gut epithelial cells which express c-met. Here we describe the response of a new transformed human jejunal epithelioid cell line (HIE-7) to HGF/SF. Morphologically HIE-7 cells are immature. Their epithelial lineage was confirmed by reactivity with the epithelial specific antibodies AE1/AE3, Cam 5.2, Ber-EP4 and anti-EMA and is consistent with their expression of c-met mRNA and protein. In addition, electron microscopic analysis revealed the presence of primitive junctions and rudimentary microvilli, but features of polarization were absent. When grown on reconstituted basement membranes, HIE-7 cells formed closely associated multicellular cord-like structures adjacent to acellular spaces. However, the cells did not mature structurally, form lumen-like structures or express disaccharidase mRNA, even in the presence of recombinant HGF (rHGF). On the other hand, rHGF induced HIE-7 cells to scatter and stimulated their rapid migration in a modified wound assay. To determine whether the motogenic effect caused by rHGF is associated with HIE-7 cell invasiveness across reconstituted basement membranes, a Boyden chamber chemoinvasion assay was performed. rHGF stimulated a 10-fold increase in the number of HIE-7 cells that crossed the basement membrane barrier, while only stimulating a small increase in chemotaxis across a collagen IV matrix, suggesting that the cytokine activates matrix penetration by these cells. rHGF also stimulated the invasion of basement membranes by an undifferentiated rat intestinal cell line (IEC-6) and by two human colon cancer cell lines which are poorly differentiated (DLD-1 and SW 948). In contrast, two moderately well differentiated colon cancer cell lines (Caco-2 and HT-29) did not manifest an invasive response when exposed to rHGF. These results suggest that HGF/SF may play a significant role in the invasive behavior of anaplastic and poorly differentiated gut epithelial tumors.Drs Sunitha and Meighen share first authorship of this paper.     

Chitosan-modified porous silicon microparticles for enhanced permeability of insulin across intestinal cell monolayers

Porous silicon (PSi) based particulate systems are emerging as an important drug delivery system due to its advantageous properties such as biocompatibility, biodegradability and ability to tailor the particles' physicochemical properties. Here, annealed thermally hydrocarbonized PSi (AnnTHCPSi) and undecylenic acid modified AnnTHCPSi (AnnUnTHCPSi) microparticles were developed as a PSi-based platform for oral delivery of insulin. Chitosan (CS) was used to modify the AnnUnTHCPSi microparticles to enhance the intestinal permeation of insulin. Surface modification with CS led to significant increase in the interaction of PSi microparticles with Caco-2/HT-29 cell co-culture monolayers. Compared to pure insulin, the CS-conjugated microparticles significantly improved the permeation of insulin across the Caco-2/HT-29 cell monolayers, with ca. 20-fold increase in the amount of insulin permeated and ca. 7-fold increase in the apparent permeability (P_app) value. Moreover, among all the investigated particles, the CS-conjugated microparticles also showed the highest amount of insulin associated with the mucus layer and the intestinal Caco-2 cells and mucus secreting HT-29 cells. Our results demonstrate that CS-conjugated AnnUnTHCPSi microparticles can efficiently enhance the insulin absorption across intestinal cells, and thus, they are promising microsystems for the oral delivery of proteins and peptides across the intestinal cell membrane.     

Barium blocks cell membrane and tight junction conductances inNecturus gallbladder epithelium

The site and concentration dependence of the blocking effect of Ba²⁺ onNecturus gallbladder epithelium has been investigated. A new approach was used which combines time-dependent electrical cell coupling analysis with intermittently performed measurements of transepithelial and apparent intracellular impedance. From the coupling pulse data the sum of apical and basolateral membrane conductances is obtained, which is then held constant during fitting of the impedance data. This combination technique yields more reliable estimates of apical and basolateral membranes resistances (R _a,R _bl) and of tight junction resistance (R _j) than our previous impedance analysis technique. Using the new approach we have found that luminal Ba²⁺ concentrations between 0.5 and 1.0 mmol/l increaseR _a with saturation-type kinetics without affectingR _bl andR _j, while higher luminal Ba²⁺ concentrations progressively increaseR _j. Corresponding effects were observed under serosal Ba²⁺. The results validate the new impedance analysis approach and demonstrate that millimolar concentrations of Ba²⁺ block tight junction conductances. Accordingly, Ba²⁺ can no longer be considered a tool to exclusively alter cell membrane resistances in epithelia.     

Generalization of map estimation in SAAM II: validation against ADAPT II in a glucose model case study

Bayesian approaches to model identification [e.g., maximum a posteriori (MAP) estimation] are receiving increasing attention in metabolism since important quantitative knowledge has become available in the last decades, e.g., from tracer experiments. By suitably exploiting this knowledge, more complex physiological models than those solely based on experimental data (Fisherian approach) become resolvable. While ADAPT II is the reference software for MAP estimation in pharmacokinetic/pharmacodynamic/metabolic system analysis, another popular, user-friendly and state-of-the-art software is SAAM II. However, SAAM II does not handle a priori information on correlation among parameters, thus allowing a limited version of MAP estimation to be performed. The aim here is twofold. First, we show that this limitation of SAAM II can be easily overcome by resorting to a probability theory result. Second, we test SAAM II vs ADAPT II implementation of MAP estimation in a real case study: the Bayesian identification of a recently proposed two-compartment minimal model of glucose kinetics during an intravenous glucose tolerance test. SAAM II MAP estimates of glucose effectiveness(S_G)and insulin sensitivity(S_I)obtained in a group of 22 healthy humans are in excellent agreement with those of ADAPT II: S _G=2.84±0.27 vs. 2.84±0.27 (ml-min^–1kg^–1, mean±SD) and S _I=11.46±1.69 vs. 11.47±1.69 [10^-2ml kg^-1,min^-1/(µU ml^-1)]. The SAAM II vs. ADAPT II estimates are virtually identical (P > 0.44 and 0.68 for S _G and S _I, respectively) and also closely correlated (=0.9998 and 0.9999). © 2002 Biomedical Engineering Society. PAC2002: 8710+e, 0250Cw     

Assessment and optimisation of dip-coating procedure for the preparation of electroenzymic glucose transducers

The details of construction and the performance characteristics of a dipcoated electroenzymic glucose transducer comprising an H₂O₂ electrode coated with a layer of glucose oxidase encapsulated in cellulose acetate and overlaid with a layer of polyurethane are presented. The steady-state current increases when the glucose oxidase and cellulose acetate concentrations of the dip-coating solutions are increased, but high cellulose acetate concentrations yield thick and mechanically unstable membranes. A compromise between current yield and mechanical stability can, however, be achieved by employing glucose oxidase and cellulose acetate concentrations of 200 mg ml⁻¹ and 2–5 g 100 ml⁻¹, respectively. A polyurethane concentration of 6 g 100ml⁻¹ is optimal both in terms of the current yield and the linearity of response. The relationship between steady-state current and D-glucose concentration is approximately linear over the concentration range 0·5 to 11·5 mm, and if correction is made for deviations from linearity at higher glucose concentrations, concentrations in excess of 20 mM can readily be quantified. The steady-state current is pH and temperature dependent, but the dependencies are relatively small in the physiological range. The mean rate of decrease of the glucose current during long-term operation of the optimised transducer is 0·83 per cent of the initial current per hour at 37°C. The hydrated electrodes perform satisfactorily after storage for more than two weeks at room temperature. the transducers have a mean response time [t _90%] of 50 s or less.     

Glucose Consumption in Rat Cerebral Cortex in Normoxia,Hypoxia and Hypercapnia

Glucose consumption was measured in the cerebral cortex of rats, anesthetized with 70% N₂O, under normoxic conditions, as well as in hypoxia (Pao₂ about 25 mmHg) and hypercapnia (Paco₂ 80–85 mmHg). The method used was that of Hawkins et al. (1974), modified to allow studies of transients in glycolytic rate. Cortical glucose consumption in normoxia was 0.77 μmol·g^-1·min^-1. It is concluded that whereas glucose consumption in the whole brain of the unanesthetized rat may be close to 0.6 μmol·g^-1·min^-1, that of the cerebral cortex is close to 0.8μmol·g^-1·min^-1. During the first 2 min of hypoxia, glucose consumption was increased to twice the normal, and during the first 2 min of hypercapnia, the corresponding value was less than one third of the normal. After 15 min of hypoxia, the glucose consumption had returned towards control values. In “steady state” hypercapnia, the glycolytic flux was higher than in the initial phase although still below normocapnic values.     

Influence of lactic acid bacteria and their spent culture supernatant on hydrogen peroxide-induced interleukin-8 synthesis and necrosis of Caco-2 cells

Intestinal epithelial cells are confronted with many noxious stimuli which play an important role in the mucosal immune response. In the present study, Caco-2 cells treated with hydrogen peroxide were used as a model system for studying inflammatory responses and induction of cell death. Live lactobacilli and their concentrated spent culture supernatant (SCS) were applied for studying possible short- and long-term protective effects against hydrogen peroxide-mediated oxidative stress in Caco-2 cells. The secretion of pro-inflammatory cytokine interleukin-8 (IL-8) was investigated in non-filter grown Caco-2 cells, while transepithelial electrical resistance and cell death was studied in filter grown Caco-2 cells. Pre-incubation of Caco-2 cells with Lactobacillus plantarum 2142 did not decrease IL-8 levels induced by 1 mM hydrogen peroxide, nor did lactobacilli suppress IL-8 levels induced by hydrogen peroxide when Caco-2 cells were treated simultaneously with 1 mM hydrogen peroxide and L. plantarum 2142. Thus, lactobacilli did not exert a long-term protective effect against hydrogen peroxide in non-filter grown Caco-2 cells. However, the concentrated SCS of lactobacilli was able to reduce IL-8 levels by more than 6-fold, as determined 24 h after treatment. A short-term effect of lactobacilli was observed in filter grown Caco-2 cells, as they inhibited cell death induced by hydrogen peroxide in the concentration range 10-40 mM. Pre-incubation of epithelial cells with L. plantarum 2142 or simultaneous exposure to hydrogen peroxide and lactobacilli protected Caco-2 cells against cell death. In spite of the presence of lactobacilli, the permeability of membrane increased (transepithelial electrical resistance decreased), and exhibited a similar characteristic pattern as under treatment with hydrogen peroxide alone.     

Identification of UAS elements and binding proteins necessary for derepression of Saccharomyces cerevisiae fructose-1,6-bisphosphatase

Summary Fructose-1,6-bisphosphatase is a key enzyme in gluconeogenesis and the FBP1 gene is not transcribed during growth with glucose. Genetic analysis indicated a positive regulation of FBP1 expression after exhaustion of glucose. By linker-deletion analysis, two upstream activation sites (UAS₁ and UAS₂) were localized and the respective UAS-binding factors (DAP I and DAP II for derepression activating protein) were identified by gel retardation. UAS₁ and UAS₂ span about 30 bp each, and are separated by approximately 30 bp. Both UAS sites act synergistically. Although UAS₁ showed some similarities to the DNA-binding consensus for the general yeast activator Rap1, competition experiments and DEAE-chromatography proved that DAP I and Rap1 correspond to different proteins. Gel retardation by DAP I depended on carbon sources and did not occur in cells growing logarithmically with glucose, whereas a strong retardation signal was obtained with ethanol-grown cells. The present results suggest that DAP I and DAP II are the final regulatory elements for glucose derepression.     

Oxidation of exogenous carbohydrate during prolonged exercise: the effects of the carbohydrate type and its concentration

Summary We studied rates of exogenous carbohydrate (CHO) oxidation during 90 min of cycling exercise in trained cyclists exercising at 70% of maximal oxygen consumption (VO_2max) when they ingested glucose, sucrose, or glucose polymer solutions at concentrations of 7.5%, 10% or 15%. Drinks were labelled with [U-¹⁴C]glucose or sucrose and were ingested at a rate of 100 ml · 10 min^–1. Rates of oxidation of the ingested CHO were calculated from the specific radio-activity of the labelled CHO, expired¹⁴CO₂ and carbon dioxide output (VCO₂). Total CHO oxidation, determined from oxygen consumption andVCO₂ was not influenced by CHO type or concentration. Gastric emptying (P=0.01) and the rate of exogenous CHO oxidation (P=0.028) was greatest for the glucose polymer solutions, and least for glucose. Although gastric emptying (P=0.006) decreased with increasing CHO concentration, CHO delivery to the intestine and exogenous CHO oxidation increased linearly with increasing CHO concentration. The percentage of the CHO delivered to the intestine that was oxidized ranged from 30.0% for 7.5% CHO to 38.1% for 15% CHO. Our results indicated that the rate of gastric emptying for CHO was not controlled to provide a constant rate of energy delivery as is commonly believed and that factors subsequent to gastric emptying limit the rate of exogenous CHO oxidation from the ingested solution.     

On the mechanism of insulinotropic action of hepoxylins: Evidence of a direct,glucose-independent effect of hepoxylins B3 on insulin secretion

The effects of lipoxygenase metabolites of arachidonic acid, hepoxylin B₃ epimers, on insulin secretion by a culture of isolated islet cells were studied. The effect was assessed at hepoxylin B₃ concentrations of 0.2 to 5.0 μM and different glucose concentrations in the culture medium. Both hepoxylin B₃ epimers were shown to boost the stimulating effect of glucose on insulin secretion. This effect manifests itself at glucose concentrations of 5.5 and 11 mM and disappears at an above normal glucose content in the medium (20 mM). The capacity of hepoxylin B₃ to stimulate the secretion of insulin by a culture of islet cells in a glucose-free medium has also been demonstrated. This direct, not glucose-mediated, insulinotropic effect may serve as proof that the hepoxylins belong to the category of intracellular messengers. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 10, pp. 404–406, October, 1995 Presented by I. G. Akmaev, Member of the Russian Academy of Medical Sciences