Comparative therapeutic efficacy of levofloxacin, ornidazole and alpha tocopherol combination with prostaglandin F2α on IL-6 and IL-10 transcript level in longstanding cases of endometritis in crossbreed Jersey cows

This study compared the therapeutic efficacy of levofloxacin, ornidazole and alpha tocopherol combination and prostaglandin F2α (PGF2α) in longstanding cases of endometritis and evaluated their impact on Interleukin-6 (IL-6) and Interleukin-10 (IL-10) transcript level in peripheral blood leukocytes. Eighteen endometritic crossbred Jersey cows were randomly allotted to three groups (six in each) viz. Group I (levofloxacin combo treatment I/U), group II (PGF2α treatment I/M), group III (no treatment, control), and group IV (six non-endometritic healthy cyclic) was taken for comparison study. The clinical efficacy was assessed by haematological study (TLC: Total leukocyte count; DC: Differential count), polymorphonuclear leukocytes (PMN) count in uterine cytology and relative mRNA expression of IL-6 and IL-10 in peripheral blood leukocytes before and after treatment with respect to conception rate following single and second inseminations. Group I and II registered significant increase in TLC and neutrophil count. PMN cytology was increased two and three fold in group I and II, respectively. The IL-6 transcript level was increased by 2.5 and 4.6 fold while that of IL-10 increased by 3.7 and 5.2 fold in group I and II, respectively. Conception rate across group I to IV following single insemination was found to be 66.67%, 50%, 16.67%, and 83.33% and their corresponding values following second insemination were 66.67%, 83.33%, 16.67%, and 83.33%, respectively. Thus, the administration of levofloxacin combo and PGF2α might have better conception rate following first and second insemination, respectively. Our study also reveals that PGF2α could register better clearance of bacteria through stronger PMN cell and cytokine activity in post-treatment period.

Spatio-Temporal Variation of Particulate Matter(PM2.5) Concentrations and Its Health Impacts in a Mega City, Delhi in India

Rising concentration of air pollution and its associated health effects is rapidly increasing in India, and Delhi, being the capital city, has drawn our attention in recent years. This study was designed to analyze the spatial and temporal variations of particulate matter (PM_2.5) concentrations in a mega city, Delhi. The daily PM_2.5 concentrations monitored by the Central Pollution Control Board (CPCB), New Delhi during November 2016 to October 2017 in different locations distributed in the region of the study were used for the analysis. The descriptive statistics indicate that the spatial mean of monthly average PM_2.5 concentrations ranged from 45.92 μg m^-3 to 278.77 μg m^-3. The maximum and minimum spatial variance observed in the months of March and September, respectively. The study also analyzed the PM_2.5 air quality index (PM_2.5-Air Quality Index (AQI)) for assessing the health impacts in the study area. The AQI value was determined according to the U.S. Environmental Protection Agency (EPA) system. The result suggests that most of the area had the moderate to very unhealthy category of PM_2.5-AQI and that leads to severe breathing discomfort for people residing in the area. It was observed that the air quality level was worst during winter months (October to January).

Certain hormonal profiles of postpartum anestrus jersey crossbred cows treated with controlled internal drug release and ovsynch protocol

Aim:

The study was conducted to determine the serum levels of certain hormones in post-partum anestrus cows following treatment with controlled internal drug release (CIDR) and Ovsynch protocol.

Materials and Methods:

A total of 30 postpartum anestrus cows were divided into three equal groups after thorough gynecoclinical examination. The Group 1 animals received an intravaginal progesterone device on day 0 and 2 ml of prostaglandin F_2α (PGF_2α) on day of CIDR removal (7^th day), Group 2 cows were treated with ovsynch protocol (gonadotropin-releasing hormone [GnRH]-PGF_2α-GnRH) on day 0, 7 and 9, respectively, and Group 3 cows were supplemented with mineral mixture and treated as control. The serum estrogen, progesterone, triiodothyronine, and thyroxine concentration were estimated using enzyme-linked immunosorbent assay kit and absorbance was read at 450 nm with Perkin Elmer Wallac 1420 Microplate Reader.

Results:

There was a significant increase in progesterone level in Group 1 after withdrawal of CIDR as compared to other two groups. However, the estrogen assay revealed a greater concentration in Group 2 against Group 1 on day 7 of sampling. However, there was no significant difference for serum triiodothyronine (T₃) and thyroxine (T₄) irrespective of treatment protocols and days of sampling.

Conclusion:

Treatment with CIDR based progesterone therapy and drug combinations may affect the reproductive hormonal balance like estrogen and progesterone, which is inevitable for successful return to cyclicity and subsequent fertilization and conception. However, as far as serum T₃ and T₄ concentration concerned it may not give an astounding result.

Roles of 5-lipoxygenase activating protein in cell proliferation and apoptosis

5-Lipoxygenase activating protein (FLAP) functions as a facilitator of 5-lipoxygenase (5-LOX) activity. However, on the basis of the induction of apoptosis by the FLAP inhibitor MK886 in cells lacking 5-LOX, it is possible that this fatty acid-binding protein has other activities. This study was designed to examine potential roles of FLAP in apoptosis and cell proliferation. Overexpression of FLAP protein (2.2-fold) was achieved by stable transfection of IL-3-dependent murine prolymphoid progenitor cells (FL5.12) with a construct expressing the cDNA under a CMV promoter. The overexpressed protein was localized to nuclear membranes as with endogenous FLAP. The initial growth rate of FLAP-transfected cells was greater than that of control cells. After 48 h, when cell density had increased, the growth rate of FLAP-transfected cells declined substantially and there and there was a decrease in viability relative to control transfected cells. The FLAP-transfected cells were also more susceptible to withdrawal of IL-3 than were control cells. There was, however, no difference between FLAP and control cells in their susceptibility to MK886, NDGA, or etoposide during the log growth phase. Overexpression of FLAP did not alter Bcl-xL protein expression, but did decrease Bax protein and somewhat increased COX-1 and COX-2 mRNA levels. The failure of increased FLAP to alter susceptibility to MK886 provides further support to the concept that this agent induces apoptosis by mechanisms unrelated to FLAP. The data also suggest that FLAP can affect cell proliferation.

Proteolytic loss of bcl-x(L) in FL5.12 Cells undergoing apoptosis induced by MK886

Apoptosis induced in the IL3-dependent murine pro-B lymphocytic (FL5.12) cell line by the 5-lipoxygenase activating protein inhibitor MK886 is accompanied by the rapid loss of the anti-apoptotic bcl-x(L) and bcl-2, but not the proapoptotic bax proteins (Datta et al., J. Biol. Chem. 273, 28163-28169, 1998). Since several reports indicate important roles for noncaspase proteases in apoptosis, the participation of lysosomes, as well as serine, cysteine, or aspartic acid proteases, in the effects of MK886 were investigated. Consistent with the involvement of various proteases, lysosomal degranulation was evident, as observed by a decrease in acridine orange fluorescence at 2 h and an increase in cytosolic beta-hexosaminidase activity at 4 h after treating FL5.12 cells with 10 microM MK886. The disappearance of bcl-x(L) from FL5.12 cells upon MK886 treatment was prevented in a dose-dependent manner by pretreatment with leupeptin, pepstatin, phenylmethylsulfonyl fluoride, or the broad-spectrum caspase inhibitor Boc-D-FMK. Each of the noncaspase protease inhibitors partially inhibited MK886-induced apoptosis as measured by phosphatidylserine externalization and DNA fragmentation. The noncaspase inhibitors also blocked about half of the increase in caspase-3-like activity. Boc-D-FMK completely inhibited this enzyme and prevented apoptosis. None of the inhibitors were able to directly inhibit activated caspase-3 in cell lysates, suggesting their effects were upstream of caspase activation. These observations suggest the involvement of various proteases, possibly originating from lysosomes, upstream of active caspase-3, in the loss of bcl-x(L) protein and in the signaling pathway of MK886-induced apoptosis in FL5.12 cells. This pathway may be unique to MK886 since these same protease inhibitors had only minimal effects on etoposide-induced apoptosis and the accompanying moderate loss of bcl-x(L) in FL5.12 cells.

Inhibition of peroxisome-proliferator-activated receptor (PPAR)alpha by MK886

Although MK886 was originally identified as an inhibitor of 5-lipoxygenase activating protein (FLAP), recent data demonstrate that this activity does not underlie its ability to induce apoptosis [Datta, Biswal and Kehrer (1999) Biochem. J. 340, 371--375]. Since FLAP is a fatty-acid binding protein, it is conceivable that MK886 may affect other such proteins. A family of nuclear receptors that are activated by fatty acids and their metabolites, the peroxisome-proliferator-activated receptors (PPARs), have been implicated in apoptosis and may represent a target for MK886. The ability of MK886 to inhibit PPAR-alpha, -beta and -gamma activity was assessed using reporter assay systems (peroxisome-proliferator response element--luciferase). Using a transient transfection system in monkey kidney fibroblast CV-1 cells, mouse keratinocyte 308 cells and human lung adenocarcinoma A549 cells, 10--20 microM MK886 inhibited Wy14,643 activation of PPAR alpha by approximately 80%. Similar inhibition of PPAR alpha by MK886 was observed with a stable transfection reporter system in CV-1 cells. Only minimal inhibitory effects were seen on PPAR beta and PPAR gamma. MK886 inhibited PPAR alpha by a non-competitive mechanism as shown by its effects on the binding of arachidonic acid to PPAR alpha protein, and a dose-response study using a transient transfection reporter assay in COS-1 cells. An assay assessing PPAR ligand-receptor interactions showed that MK886 prevents the conformational change necessary for active-complex formation. The expression of keratin-1, a protein encoded by a PPAR alpha-responsive gene, was reduced by MK886 in a culture of mouse primary keratinocytes, suggesting that PPAR inhibition has functional consequences in normal cells. Although Jurkat cells express all PPAR isoforms, various PPAR alpha and PPAR gamma agonists were unable to prevent MK886-induced apoptosis. This is consistent with MK886 functioning as a non-competitive inhibitor of PPAR alpha, but may also indicate that PPAR alpha is not directly involved in MK886-induced apoptosis. Although numerous PPAR activators have been identified, the results show that MK886 can inhibit PPAR alpha, making it the first compound identified to have such an effect.

Association between bcl-x(L) and 5-lipoxygenase activating protein (FLAP) levels in IL-3-dependent FL5.12 cells

The expression of 5-lipoxygenase activating protein (FLAP) in murine hematopoietic FL5.12 cells that are transfected to overexpress bcl-x(L) is less than in control cells. In addition, the withdrawal of IL-3 from the bcl-x(L) overexpressing cells, but not control cells, leads to the rapid loss of FLAP even though these cells, in contrast to control cells, do not undergo apoptosis (Datta et al., J. Biol. Chem. 273, 28163-28169 [1998]). The mechanism(s) underlying these observations is not known. Basal FLAP mRNA levels were actually 2.8-fold higher in bcl-x(L) than control cells indicating that this difference does not have a transcription basis. In addition, an examination of FLAP mRNA levels in response to withdrawal of IL-3 revealed a 2-3-fold increase after 4 and 8 h relative to time-matched samples in both control and bcl-x(L) overexpressing cells. This further indicates that the decrease in FLAP levels in bcl-x(L) overexpressing cells is not related to transcription and suggests an attempt at compensation perhaps in response to increased FLAP degradation/turnover. A proteolytic mechanism was explored by examining the effect of the general caspase inhibitor Boc-D-FMK, and the non-caspase protease inhibitors phenylmethylsulfonyl fluoride (PMSF), pepstatin and leupeptin, on the loss of FLAP in bcl-x(L) overexpressing cells subsequent to IL-3 withdrawal. All inhibitors provided some protection from the loss of FLAP, with PMSF being the most effective, actually increasing FLAP levels above those seen in untreated cells. Given the absence of apoptosis in bcl-x(L) cells, it appears that protease activation is an effect that can accompany a variety of cellular perturbations. The functional consequences of a loss of FLAP in growth-factor deprived cells overexpressing bcl-x(L) is not known. However, these data continue to suggest some link between bcl-x(L) and FLAP.

Changes in ceramide and sphingomyelin following fludarabine treatment of human chronic B-cell leukemia cells

Fludarabine is used to treat chronic lymphocytic leukemia. Both in vitro and in vivo studies have indicated that apoptosis is an important mode of fludarabine-induced cell death. However, the apoptotic pathways activated are not known. The effects of apoptotic doses of fludarabine on sphingomyelin, ceramide and the production of reactive oxygen species were investigated in the chronic B-cell leukemia lines WSU and JVM-2. Apoptosis, as assessed by an increase in phosphatidylserine externalization, internucleosomal DNA fragmentation and caspase-3-like activity, was evident by 18 h after fludarabine in both cell lines. The general caspase inhibitor t-butoxycarbonyl-Asp(OMe)-fluoromethyl ketone (OMe, methyl ester) significantly inhibited apoptosis supporting a role for caspases in fludarabine-induced cell death. A 2.5- to threefold elevation in ceramide levels was observed 6 h after fludarabine treatment. Concomitantly, a decrease in sphingomyelin levels was observed. Fumonisin B1 (an inhibitor of ceramide synthase) pretreatment significantly prevented fludarabine-induced ceramide generation and apoptosis. Conversely, C6-ceramide induced apoptosis in both cell lines. No effect of fludarabine on indices of oxidative stress (dichlorofluorescin oxidation and glutathione disulfide formation) were detected, although partial protection from apoptosis, and prevention of ceramide generation and caspase-3 activation, were achieved with N-acetylcysteine. These findings are consistent with the involvement of caspases and ceramide in fludarabine-induced apoptosis in WSU and JVM-2 cells. Oxidative stress does not appear to be induced by fludarabine, although the protective effects of N-acetylcysteine suggest that thiol redox balance may play a role in the apoptotic pathway.

The molecular effects of acrolein

Acrolein is a highly electrophilic alpha,beta-unsaturated aldehyde to which humans are exposed in a variety of environmental situations, particularly as a component of smoke. In addition, as a metabolite of cyclophosphamide, acrolein is a major factor in the toxicity and perhaps the therapeutic activity of this important anticancer agent. The exposures to acrolein that are attained in vivo in most situations are quite low and the effects may differ from those seen at acutely toxic doses. At low doses, acrolein inhibits cell proliferation without causing cell death and may enhance apoptosis from secondary toxins, while at higher doses oncosis ensues. Although the acute toxicology of acrolein has been extensively investigated, both in animals and cultured cells, little information exists on the molecular effects of this reactive aldehyde. It is possible that the acrolein-mediated decrease in cell proliferation is caused by effecting changes in the expression of one or more growth- or stress-related genes or transcription factors secondary to a reduction in glutathione (GSH), which is rapidly depleted following acrolein treatment. It is apparent that the activation of the transcription factors nuclear factor kappa B (NF-kappa B) and activator protein 1 (AP-1) can be inhibited by acrolein. The purpose of this review is to assess the literature currently available on the molecular effects of acrolein, to discuss the relationship between effects on glutathione with those on various genes, and to present some new data showing that acrolein actively stimulates genes associated with the electrophile response element.

Glutathione oxidation and mitochondrial depolarization as mechanisms of nordihydroguaiaretic acid-induced apoptosis in lipoxygenase-deficient FL5.12 cells

Nordihydroguaiaretic acid (NDGA) induces apoptosis in a variety of cell lines. The mechanism(s) of this effect is not known, although the focus has been on the ability of NDGA to inhibit lipoxygenase (LOX) activities. In the present study, NDGA-induced apoptosis was studied in a murine hematopoietic cell line, FL5.12. Although this cell line lacks detectable LOX protein or activities, NDGA (10 microM) was able to induce apoptosis. There was a massive loss of mitochondrial membrane potential by 4 h after the addition of NDGA, suggesting that this organelle might be targeted by NDGA. A pro-oxidant NDGA effect has been suggested as playing a role in apoptosis. This was supported by the findings that glutathione disulfide levels were increased by 4 h following treatment with 10 microM NDGA, that pretreatment with N-acetylcysteine completely blocked the NDGA-induced loss of membrane potential and apoptosis, and that lipid peroxidation was enhanced in cells treated with NDGA. However, no evidence of increased levels of reactive oxygen could be seen in NDGA-treated cells loaded with dichlorofluorescin diacetate or dihydrorhodamine and analyzed by flow cytometry. Bcl-X(L) protein levels were unaffected by NDGA treatment. Caspase-3 was rapidly activated with a peak at 8 h after FL5.12 cells were treated with NDGA. Ac-DEVD-CHO (25 microM) and boc-asp-FMK (20 microM) both inhibited caspase-3 enzyme activity by 97% 8 h after NDGA treatment. Boc-asp-FMK, a more general caspase inhibitor, delayed NDGA-induced apoptosis while Ac-DEVD-CHO, a more specific inhibitor of caspase-3, had no effect. These results suggest that NDGA-induced apoptosis happens through reactions that depolarize mitochondria, oxidize glutathione and lipids, but do not generate significant amounts of free reactive oxygen species.

Heat-shock protein 70 antisense oligomers enhance proteasome inhibitor-induced apoptosis

Recent evidence supports a role for heat-shock protein 70 (hsp70) and the 26 S proteasome in regulating apoptosis, although the precise nature of their involvement is not known. In the present study, control and Bcl-x(L)-overexpressing, interleukin-3-dependent FL5.12 cell lines were treated with the proteasome inhibitor N-benzoyloxycarbonyl (Z)-Leu-Leu-leucinal (MG132). Basal proteasome activity appeared to be approximately 30% lower in bcl-x(L) cells compared with control cells using a substrate for the chymotrypsin-like activity. However, no difference in proteasome activity was detected using substrates for the trypsin-like or peptidylglutamyl peptide-hydrolysing activities. In addition, protein levels of the 20 S proteasome beta-subunit, as determined by Western blot analyses, were similar in control and bcl-x(L) cells, leading to the conclusion that proteasome activities were the same in these two cell lines. At 24 h after treatment with 500 nM MG132, apoptosis in bcl-x(L) cells (22%) was less than that observed in control cells (34%). Concomitantly, caspase activity in control cells, as assessed by N-acetyl-l-aspartyl-l-glutamyl-l-valyl-l-aspartyl-7-amino-4-methylcou marin (Ac-DEVD-AMC), was twice that observed in bcl-x(L) cells. By 48 h after MG132 treatment, apoptosis and caspase activity in bcl-x(L) cells were similar to those observed in control cells at 24 h. Proteasome inhibition stimulated increases in hsp70 protein levels in control and bcl-x(L) cells by 12 h, although the maximal increases found in bcl-x(L) cells were less. Blocking this induction with hsp70 antisense oligonucleotides potentiated apoptosis after treatment with MG132. Inhibiting caspase activity with a broad-spectrum caspase inhibitor, t-butoxycarbonyl-Asp(OMe)-fluoromethyl ketone, prevented MG132-induced apoptosis. The more specific caspase-3 inhibitor, Ac-DEVD-aldehyde, afforded less protection, although both inhibitors completely inhibited Ac-DEVD-AMC cleavage. These data indicate that both hsp70 and Bcl-x(L) provide some protection against proteasome inhibitor-induced apoptosis.

The 5-lipoxygenase-activating protein (FLAP) inhibitor, MK886, induces apoptosis independently of FLAP

The ability of various inhibitors of lipoxygenase (LOX) enzymes and 5-lipoxygenase-activating protein (FLAP) to induce apoptosis has implicated these pathways in the mechanism(s) of this form of cell death. Although FLAP plays an important role in 5-LOX activity, this protein is found at high levels in some cells lacking LOX, suggesting it might mediate other effects. Furthermore, the concentration of MK886, a FLAP inhibitor, required to induce apoptosis is approximately 100-fold more than that required to inhibit LOX, and this compound remains effective in cells lacking LOX. The present study examines the role of FLAP in MK886-induced apoptosis. MK886 induced apoptosis in WSU cells, a human chronic lymphocytic leukaemia cell line that lacks FLAP protein and mRNA, suggesting that this agent is acting independently of FLAP. This conclusion was further supported by the fact that a more specific FLAP inhibitor, MK591, induced only minimal apoptosis in FL5.12 cells, a murine prolymphoid cell line containing FLAP. The role of FLAP was examined more directly by decreasing its expression by more than 50% in FL5.12 cells treated with 10 microM of an antisense oligonucleotide for 48h. This change in FLAP was not accompanied by any increase in apoptosis. Furthermore, FLAP-depleted cells exhibited the same level of apoptosis 8 h after treatment with 10 microM MK886, as did control cells. The increased fluorescence seen in MK886-treated cells loaded with carboxydichlorofluorescein indicates that oxidative reactions are stimulated by this compound, possibly via the release of fatty acids from fatty acid-binding proteins and their subsequent oxidation.

Acrolein causes inhibitor kappaB-independent decreases in nuclear factor kappaB activation in human lung adenocarcinoma (A549) cells

Acrolein is a highly electrophilic alpha,beta-unsaturated aldehyde to which humans are exposed in various situations. In the present study, the effects of sublethal doses of acrolein on nuclear factor kappaB (NF-kappaB) activation in A549 human lung adenocarcinoma cells were investigated. Immediately following a 30-min exposure to 45 fmol of acrolein/cell, glutathione (GSH) and DNA synthesis and NF-kappaB binding were reduced by more than 80%. All parameters returned to normal or supranormal levels by 8 h post-treatment. Pretreatment with acrolein completely blocked 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced activation of NF-kappaB. Cells treated for 1 h with 1 mM diethyl maleate (DEM) showed a 34 and 53% decrease in GSH and DNA synthesis, respectively. DEM also reduced NF-kappaB activation by 64% at 2 h post-treatment, with recovery to within 22% of control at 8 h. Both acrolein and DEM decreased NF-kappaB function approximately 50% at 2 h after treatment with TPA, as shown by a secreted alkaline phosphatase reporter assay. GSH returned to control levels by 8 h after DEM treatment, but proliferation remained significantly depressed for 24 h. Interestingly, DEM caused a profound decrease in NF-kappaB binding, even at doses as low as 0.125 mM that had little effect on GSH. Neither acrolein nor DEM had any effect on the levels of phosphorylated or nonphosphorylated inhibitor kappaB-alpha (IkappaB-alpha). Furthermore, acrolein decreased NF-kappaB activation in cells depleted of IkappaB-alpha by TPA stimulation in the presence of cycloheximide, demonstrating that the decrease in NF-kappaB activation was not the result of increased binding by the inhibitory protein. This conclusion was further supported by the finding that acrolein modified NF-kappaB in the cytosol prior to chemical dissociation from IkappaB with detergent. Together, these data support the conclusion that the inhibition of NF-kappaB activation by acrolein and DEM is IkappaB-independent. The mechanism appears to be related to direct modification of thiol groups in the NF-kappaB subunits.

A relationship between 5-lipoxygenase-activating protein and bcl-xL expression in murine pro-B lymphocytic FL5.12 cells

Inhibitors of 5-lipoxygenase-activating protein (FLAP) have been found to induce apoptosis. The current study examined the expression of FLAP and bcl family proteins and the induction of apoptosis in interleukin-3-dependent control and bcl-xL-overexpressing FL5.12 cell lines after treatment with MK886, a specific FLAP inhibitor. FL5.12 cells contained a substantial amount of FLAP protein and mRNA but surprisingly had no measurable 5-lipoxygenase protein or 5-, 12-, or 15-lipoxygenase activity. The basal level of FLAP protein in cells overexpressing bcl-xL was 70% less than in controls. FLAP disappeared 4 h after withdrawal of interleukin-3 in bcl-xL cells but not in control cells, which underwent apoptosis. A dose- and time-response study revealed that 5 nmol of MK886/10(6) cells was sufficient to induce apoptosis both in control and bcl-xL cells, respectively, but to different degrees. bcl-xL and bcl-2 proteins, but not bax or FLAP, were decreased by 4 h after 5 nmol of MK886/10(6) cells in both cell lines, although the higher levels of bcl-xL in overexpressors took longer to disappear. This early loss of bcl-xL and bcl-2 was not attributable to generalized proteolysis, as shown by Coomassie Blue staining and by the maintenance of bax. Caspase-3 was activated 2 h after MK886 treatment in control cells but not in bcl-xL cells. Inhibition of caspase-3 decreased MK886-induced apoptosis by 50% in control cells. Inhibition of this caspase after MK886 treatment was unable to prevent the loss of bcl-xL in control cells but did provide partial protection for the loss of the transfected form, but not the endogenous form, in overexpressing cells. These data indicate that MK886 induces extensive apoptosis that is partially caspase-3 dependent and may be related to a rapid loss of bcl-xL. Although caspase-3 inhibitors had no effect on the loss of bcl-xL, other caspases or protease systems may still be involved. The absence of 5-lipoxygenase in cells containing FLAP, the lower level of FLAP in bcl-xL cells, the apoptosis-inducing activity of MK886, and the rapid loss of bcl-xL and bcl-2 proteins after treatment with MK886 strongly indicate that FLAP has activities unrelated to lipoxygenase and suggest a possible functional or regulatory link between these proteins, which share similar subcellular localizations.