The impaired synthesis of insulin and its inability to inhibit platelet aggregation in cerebrovascular accident.

Both ischemic stroke (IS) and hemorrhagic stroke (HS) are reported to occur due to thrombosis on the arteries of the brain. As diabetes mellitus is a risk factor for strokes and insulin is reported to prevent thrombosis, the role of insulin in IS and HS was investigated. Forty eight stroke victims (IS = 22, HS = 26) and equal number of aged and sex matched normal volunteers participated in the study. Nitric oxide was determined by methemoglobin method. Insulin and Dermcidin isoform-2 (DCN2) level was determined by ELISA by using insulin and dermcidin antibody. Insulin binding to the platelet membrane was analyzed by scat chard plot. Treatment of normal platelet rich plasma (10(8)platelets/ml) with 15µUnits insulin/ml produced 1.41 nmol NO. The PRP from the IS and HS victims produced 0.38 nmol NO and 0.08 nmol NO respectively. Pretreatment of PRP from IS or HS subjects with 15 µM aspirin followed by 15µUnits of insulin/ml resensitized the platelets to the inhibitory effect of insulin. Mice hepatocytes treated with 0.14 µM DCN2 abolished the glucose induced insulin synthesis by NO that can be reversed by using 15 µM aspirin. It can be concluded that presence of DCN2 in stroke causes a condition similar to type I diabetes and nullified the effect of insulin in the inhibition of platelet aggregation in both IS and HS. The effect was reversed by 15 µM aspirin.

The diagnosis of high altitude illness by the determination of plasma dermcidin isoform 2 levels by enzyme linked immunosorbent assay.

BACKGROUND: High altitude illness (HAI) is a cluster of syndromes which develops due to the injury of the central nervous system produced by the reduction of the partial pressure of O2 in the atmosphere which disappears on decent. The HAI also results in a prothrombotic condition leading to acute coronary syndrome (ACS), which cannot be controlled on descent to the ground level. There is no diagnosis in HAI to forewarn of the impending ACS. A protein identified to be dermcidin isoform 2 (dermcidin), produced in the system due to environmental stresses, has been reported to be a potent diabetogenic agent. Investigation was carried out to determine the systemic stimulation of dermcidin synthesis at different levels of altitudes in normal adult male volunteers to assess the feasibility of developing a diagnosis for ACS in HAI due to dermcidin synthesis. METHODS: Normal, nondiabetic, normotensive male volunteers (25 - 35 years old, n = 16) participated in the study. The plasma dermcidin level was determined by enzyme linked immunosorbent assay (ELISA) and by in vitro translation of dermcidin mRNA. The plasma insulin level was determined by ELISA and blood glucose level was determined in a glucometer (Behringer). RESULTS: The plasma dermcidin level in the volunteers at ground level was 10 +/- 2.10 nM and increased to 80 +/- 4.62 nM at 15000 feet altitude. For each 1000 feet increase of altitude, the dermcidin level increased by 5.83 +/- 0.21 nM with a Coefficient of Correlation "r" = +0.9405. The increase of plasma dermcidin level was found to be inversely related to the decrease of plasma insulin level from 23 microunit/mL to 5 microunit/mL from sea level to 15000 feet height ("r" = -0.9951) with concomitant increase of blood sugar level from 80 +/- 3.6 mg/dL to 135 +/- 2.01 mg/dL. CONCLUSIONS: These results suggest the feasibility of a diagnosis of a prediabetic condition by determining the plasma dermcidin level in HAI by simple ELISA which may also be useful to forewarn of the possibility of developing an impending prothrombotic condition in HAI.

Diagnosis of essential hypertension in humans by the determination of plasma renal cortexin using enzyme-linked immunosorbent assay.

BACKGROUND: More than 90% of all hypertensive persons are reported to have essential hypertension (EH), a particular form of elevated blood pressure, for which no diagnostic test is currently available. The level of plasma renal (R) cortexin (PRC), a hypotensive protein produced in the kidney cortex cells, was reported to be reduced from 218 nM in the plasma of normotensive persons (NP) to 0 nM in the plasma of patients with EH. The feasibility of using the determination of PRC by enzyme-linked immunosorbent assay (ELISA) as a diagnostic test for EH was investigated. METHODS: The PRC was determined by ELISA using electrophoretically pure cortexin as the antigen. A total of 344 persons (male and female) with EH, with or without diabetes mellitus (DM), and receiving or not receiving any anti-hypertensive and/or anti-diabetic medication at presentation, as well as an equal number of age- and gender-matched NP participated in the study. RESULTS: All persons with EH, with or without co-existing DM, were found to have 0 nM PRC, regardless of whether they were receiving anti-hypertensive and anti-diabetic drugs, including those who had been taking these medications over an extended period of time (3 months). CONCLUSIONS: The determination of PRC as a marker protein by ELISA, a rapid method that can be carried out in any diagnostic laboratory, was shown to be suitable for the diagnosis of EH, even in those subjects who had co-existing DM and were receiving both anti-hypertensive and anti-diabetic medication.

Isolation and study of insulin activated nitric oxide synthase inhibitory protein in acute myocardial infarction subjects.

Insulin inhibits platelet aggregation through nitric oxide synthesis by stimulating platelet insulin activated nitric oxide synthase. Impaired platelet insulin activated nitric oxide synthase in acute myocardial infarction (AMI) patients had been reported and thus our aim was to identify and isolate the factors impairing insulin activated nitric oxide in acute myocardial infarction patients' plasma and study its effect on platelets aggregation in vitro. The insulin activated nitric oxide synthase inhibitor was identified as a protein and was purified from the plasma of AMI subjects using DEAE cellulose and Sephadex G-50 column, molecular weight determined by SDS-PAGE, nitric oxide quantified by methaemoglobin method, inhibitor protein quantified in plasma by immunoblot and ELISA, platelet aggregation studies done using an aggregometer, thromboxane-A2 in the platelets determined by radioimmunoassay, (125)I-insulin radioligand binding studies done using normal subject platelets. The purified nitric oxide synthase inhibitor protein was ~66 kDa, concentration in AMI subjects' plasma varied from 114 to 9,090 µM and was undetected in normal subjects' plasma. The inhibitor protein competes with insulin for insulin receptor binding sites. The Incubation of the normal subject PRP with 5.0 µM inhibitor for 30 min followed by 0.4 µM ADP addition caused platelet aggregation in vitro, 130 µM aspirin or 400 µU insulin/ml addition was able to abrogate 0.4 µM ADP induced platelet aggregation even in the presence of 5.0 µM inhibitor. A potent inhibitory protein against insulin activated nitric oxide synthase in platelets appears in circulation of AMI subjects impairing nitric oxide production, potentiating ADP induced platelet aggregation and increasing the thromboxane-A2 level in platelets.

Acetyl salicylic acid (aspirin) improves synthesis of maspin and lowers incidence of metastasis in breast cancer patients [corrected].

Maspin, a 42 kDa protein produced in normal breast cells, has been shown to inhibit the invasion and metastasis of breast cancer in an animal model. Ingestion of acetylsalicylic acid (aspirin) by breast cancer patients has been reported to restore the systemic synthesis of maspin through the stimulation of systemic nitric oxide production. Studies were carried out to determine the effect of aspirin on the incidence of breast cancer metastasis, which is reported to occur in 50% of patients who have previously received chemotherapy, radiation, and/or surgery. Thirty-five female patients (aged 41-65 years) with breast cancer who had previously received these therapies took one 75 mg/70 kg body weight enteric-coated aspirin tablet every 24 h, after an adequate meal, for 3 years. Their plasma nitric oxide and maspin levels were measured. The occurrence of metastasis was ascertained monthly by a qualified oncologist, and confirmed, if necessary, by biopsy. Daily ingestion of aspirin by participants resulted in an increase in maspin levels from 0.95 ± 0.04 to 4.63 ± 0.05 nM after 24 h. These levels were maintained for 3 years. These studies suggest that daily ingestion of aspirin might significantly reduce the incidence of breast cancer metastasis in patients who have previously received anticancer therapies.

Antidiabetic role of a novel protein from garlic via NO in expression of Glut-4/insulin in liver of alloxan induced diabetic mice.

INTRODUCTION: Garlic has been reported to stimulate nitric-oxide (NO) synthesis in various cells. The role of aqueous-extract of garlic (AEG) and a purified NO-generating protein from garlic (NGPG) was investigated to control hyperglycemia by hepatic insulin synthesis through NGPG induced synthesis of NO via glucose-activated NO-synthase and glucose transporter-4 (Glut-4) in the hepatocytes. METHODS: Type-1-diabetic mellitus mice were prepared by alloxan treatment, NO was determined by methemoglobin method, insulin synthesis was quantitated by ELISA. TNF-α and NFκß was quantitated by ELISA. The AEG-induced Glut-4 synthesis was determined by in-vitro translation of mRNA from the hepatocytes. The NO-generating protein from AEG was purified to homogeneity by chromatography on DEAE-cellulose and Sephadex G-50 columns and sequenced/characterized by Mass-spectral-analysis. RESULTS: Purified NGPG injection to diabetic mice significantly reduced the blood-sugar and increase insulin level in diabetic animal. It also increases insulin-release, Glut-4 synthesis, glucose-uptake in both liver and ß-cells of diabetic mice. NGPG down regulated pro-inflammatory cytokine TNF-α and the stress responsive NFκB-expression in liver cell of diabetic mice. Injection of AEG to the diabetic mice reduced the blood glucose level from 550 ± 10 mg/dL to 125 ± 10 mg/dL in 16 h with simultaneous increase of plasma NO from 0 nmol/h to 2.5 nmol/h and insulin 2 ± 1.1µunit/mL to 15µunit/mL at 16 h. Oral administration of AEG to adult diabetic mice increased NO, insulin and Glut-4 synthesis in the hepatocytes. CONCLUSION: AEG and the purified-NGPG protein can control hyperglycemia through the stimulation of NO by glucose-activated NO-synthase that would play an important role in the synthesis of insulin/Glut-4 in liver-cells.

Insulin resistance in prostate cancer patients and predisposing them to acute ischemic heart disease.

Lack of insulin or insulin resistance (IR) plays a central role in diabetes mellitus and makes diabetics prone to acute ischemic heart disease (AIHD). It has likewise been found that many cancer patients, including prostate cancer patients die of AIHD. Previously it has been delineated from our laboratory that dermcidin could induce anomalous platelet aggregation in AIHD and also impaired nitric oxide and insulin activity and furthermore dermcidin was also found in a few types of cancer patients. To determine the role of this protein in prostatic malignancy, a retrospective case-control study was conducted and blood was collected from prostate cancer patients and healthy normal volunteers. So, we measured the level of dermcidin protein and analyzed the IR by Homeostasis Model Assessment (HOMA) score calculation. Nitric oxide was measured by methemoglobin method. HDL, glycated hemoglobin (HbA1c), BMI, hs-cTroponin-T were measured for the validation of the patients' status in the presence of Dermcidin isoform-2 (DCN-2). Multiple logistic regression model adjusted for age and BMI identified that the HOMA score was significantly elevated in prostate cancer patients (OR = 7.19, P<0.001). Prostate cancer patients are associated with lower level of NO and higher level of both proteins dermcidin (OR = 1.12, P<0.001) and hs-TroponinT (OR = 1.76, P<0.001). From the results, it can be interpreted that IR plays a key role in the pathophysiology of prostate cancer where dermcidin was the cause of IR through NO inhibition leading to AIHD was also explained by high-sensitive fifth generation cTroponin-T (hs-cTroponinT) and HbA1c level which are associated with endothelial dysfunction.

Estriol Inhibits Dermcidin Isoform-2 Induced Inflammatory Cytokine Expression Via Nitric Oxide Synthesis in Human Neutrophil.

BACKGROUND: An increase in the level of cytokines like TNF-α and IL-6 causes the inflammatory surge in acute ischemic heart disease (AIHD). OBJECTIVE: A high-level dermcidin isoform-2 (DCN-2) occurrence in AIHD was subjected to determine a possible regulation of cytokines expression. The effect of estrogen to counteract the inflammatory response was determined. METHODS: Blood was collected from AIHD patients and normal volunteers with consent. Nitric oxide (NO) synthesis was done with methemoglobin method.TNF-α and IL-6 expression were determined by ELISA and Western blot. RESULTS: (DCN-2) incubation with 120nM to the normal neutrophil solution for 2h resulted in the increase of TNF-α from 3.82±1.53pg/ml to 20.7±6.9pg/ml and IL-6 from 3.27±1.52pg/ml to 47.07±3.4pg/ml. In AIHD patients, the cytokine level was18.3- 27.3pg/ml, with a median value 21.86pg/ml (TNF-α) and IL-6 level was 23.54- 52.73pg/ml, with a median value 42.16pg/ml. Treatment with 0.6nM estriol, a kind of female steroid hormone estrogen for 45min decreased the elevated cytokine level in 120nM DCN-2 treated normal neutrophils. DCN-2 induced TNF-α synthesis in neutrophils was further determined by Western blot technique with a thickened band intensity of TNF-α. Estriol (0.6nM) treatment also influenced the DCN-2 induced inhibition of nitric oxide (NO) synthesis from 0nmol NO/ml to 0.56nmol/ml. The subsequent reduction of TNF-α level correlates the increase of NO level. CONCLUSION: In conclusion, the stress-induced DCN-2 production in AIHD propagates the inflammatory response. Steroid molecule like estriol plays a protective role by reducing DCN-2 responses in the NO synthesis.

Systemic production of IFN-alpha by garlic (Allium sativum) in humans.

The effect of foods on the production of interferon-alpha (IFN-alpha) is currently unknown. Garlic (Allium sativum) used as a folk medicine is reported to stimulate nitric oxide (NO) production. We investigated the systemic increase of NO due to the ingestion of garlic on the plasma IFN-alpha level in normal volunteers. Normal volunteers (10 groups, 10 in each group) ate 2 g fresh garlic, and plasma NO and IFN-alpha levels were determined after 2 and 4 h. The participants were also asked to eat garlic for various periods of time, and plasma NO and IFN-alpha were similarly assayed. Ingestion of 2 g fresh, but not boiled, garlic was found to increase the basal plasma level of NO from 2.7 +/- 0.1 microM to 8.76 +/- 0.21 microM at 2 and 4 h, respectively. The basal plasma IFN-alpha level increased from 9.51 +/- 0.26 nM to 46.3 +/- 1.2 nM in normal volunteers (n = 10) at the same time. The chronic eating of garlic was found to maintain IFN-alpha at high levels for at least 7 days. The exposure of neutrophils to garlic in vivo or in vitro, which also stimulated synthesis of NO in these cells, was found to stimulate IFN-alpha synthesis as measured by the stimulation of IFN-alpha mRNA synthesis. Thus, consumption of garlic resulted in stimulated synthesis of NO and, in turn, IFN-alpha in humans, which could be beneficial in viral or proliferative diseases.

Expression of a Nitric Oxide Synthesizing Protein in Arterial Endothelial Cells in Response to Different Anti-Anginal Agents Used in Acute Coronary Syndromes.

BACKGROUND: Organic "nitro" compounds such as nitroglycerine, isosorbide dinitrate are useful in the control of chest pain in acute coronary syndrome. But the mechanism of it in pain regulation remains speculative. Here, increase of NO production was investigated by the possible regulation of constitutive nitric oxide synthase (cNOS) function from goat arterial endothelial cells. This protein was purified and sequence wise characterized as protein disulfide isomerase (PDI) in response to different nitro compounds. METHOD: The NO generating protein was isolated from arterial endothelial cells and prepared to homogeneity. NO was determined by methemoglobin method. Protein sequence was analyzed by (µLC/MS/MS). RESULTS: A protein of Mr. ~57 kDa was isolated and found to be activated by not only "nitro" compounds but also by acetyl salicylic acid, insulin and glucose. The global BLAST of the protein sequence showed a significant alignment of the protein sequence with PDI. This protein trivially called pluri activator stimulated endothelial NOS (PLASENOS). The enzyme was stimulated by the above-mentioned activators in the presence of Ca2+. Lineweaver-Burk plot of this NOS like activities were demonstrated with its specific substrate l-arginine as Vmax = 5(nmol NO/mg of protein/hr) and Km≈ 0.5µM by the above activators. The enzyme activity was inhibited by the l-NAME, the specific inhibitor of NOS. CONCLUSION: The organic nitro compounds, acetyl salicylic acid, insulin and glucose were found to activate PLASENOS in the arterial endothelial cells for a continuous supply of NO to control the chest pain in acute coronary syndrome.

The control of hyperglycemia by a novel trypsin resistant oral insulin preparation in alloxan induced type I diabetic mice.

A trypsin resistant oral insulin preparation was made by incubating insulin for 2 h at 23 °C with previously boiled cow milk at 100 °C that was coagulated with 0.6 M acetic acid. The precipitate was resuspended in the same volume of milk. The immunoblot analysis of the suspended proteins treated with 200 ng of trypsin/ml for 3 h demonstrated that the 80.1% of the insulin in the suspension survived the proteolytic degradation compared to 0% of the hormone survived in the control. The feeding of 0.4 ml (0.08 unit of insulin) of the resuspended proteins followed by 0.2 ml of the same protein to alloxan induced diabetic mice maximally decreased the blood glucose level from 508 ± 10 mg/dl to 130 ± 10 mg/dl in 7 h with simultaneous increase of the basal plasma concentration of insulin from 3 ± 1.1 µunits/ml to 18 ± 1.5 µunits/ml. In control experiment the absence of insulin in the identical milk suspension produced no hypoglycemic effect suggesting milk was not responsible for the hypoglycemic effect of milk-insulin complex. Coming out of insulin-casein complex from the intestinal gut to the circulation was spontaneous and facilitated diffusion transportation which was found from Gibbs free energy reaction.

Appearance of a novel prostacyclin receptor antibody and duration of spinal cord injury.

BACKGROUND: Cardiovascular disease (CVD) appears to be accelerated in individuals with chronic spinal cord injury (SCI). Previously, we have identified a novel circulating antibody (IgG) in persons with SCI that specifically blocks the high-affinity prostacyclin (PGI2) receptors on the platelet surface without affecting the low-affinity PGI2 receptors. OBJECTIVE: In this study, the relationship between the time course after SCI to the development of IgG to the high-affinity PGI2 receptor was determined. METHODS: Blood samples were collected 1, 3, 5, 10, and > 10 (15 +/- 4) years after SCI (n = 36). Plasma samples (50 microg) were analyzed by polyacrylamide gel electrophoresis (PAGE) followed by densitometry. RESULTS: The optical density (OD) of the IgG (molecular weight 47,000) at 1 year after SCI was significantly higher than control (1.65 +/- 0.08 vs 1.33 +/- 0.04; P < 0.01). This anti-receptor IgG appears to increase for 5 years and then plateau. At 5 years, 6-10 years, and > 10 years of injury, the OD was 1.83 +/- 0.09, 1.83 +/- 0.10, and 1.87 +/- 0.08, respectively. With an increase in this specific IgG, there was a concomitant decrease in the binding of prostacyclin to its high-affinity receptors on SCI platelets, (non-SCI vs 1, 3, and 5 years after injury; n1 = 172 +/- 25 vs 153 +/- 15, 107 +/- 25, and 40 +/- 4 sites/platelet, respectively; P < 0.001), with no significant change in receptor affinity. CONCLUSIONS: The level of the high-affinity PGI2-receptor antibody determined in individuals with SCI was associated with the duration and not with the level of injury. Platelets from subjects with SCI had a reduction in numbers of high-affinity receptors.

Neutralization by Acetyl Salicylic Acid of the Testosterone induced Impaired Maspin Synthesis Stimulated by Estriol in Neutrophils through Nitric Oxide Synthesis.

PURPOSE: Maspin, an anti breast cancer protein in the mammary cell and normal neutrophil has been reported to be synthesised by the stimulation of NO production induced by estriol. The role of testosterone was investigated in the synthesis of maspin in relation to that of estriol. METHODS: Fifty normal female between the ages of 25-65 years old participated in the study. Maspin synthesis was demonstrated by in vitro translation of maspin mRNA, followed by the quantification of maspin by enzyme linked immune absorbent assay. NO was determined by methomoglobin method. RESULTS: Incubation of the neutrophils in HBSS both with 30 nM estriol resulted in the synthesis of 1.8 ngm maspin with simultaneous increase of NO synthesis. In contrast incubating neutrophils with 20 nM testosterone in the presence of estriol inhibited maspin synthesis to 0.33 nM with simultaneous inhibition of NO synthesis from 1.89 nM to 0 nM at the same time. Addition of 0.2µM flutamide, a testosterone receptor blocker to the incubation mixture restored the synthesis of maspin by 60.64 %. Incubation of 25µM aspirin that stimulated NO synthesis restored the inhibition of maspin synthesis by testosterone by 79.1%. I-NAME, an inhibitor of nitric oxide synthase, abolished both maspin and NO synthesis. Scatchard plot of estriol binding in the presence of testosterone demonstrated that the male sex hormone inhibited the female sex hormone binding to its receptor by "cross talk" between the receptors. It was found that while 1.02 × 10(3) molecules of estriol bind each neutrophil at equilibrium, in the presence of testosterone (20nM) in the binding mixture decreases the binding of estriol to 0.5 × 10(3) with little change in the dissociation constant compared to controls. CONCLUTION: Estriol was found to stimulate maspin synthesis through the stimulation of NO, testosterone inhibited maspin synthesis through the inhibition of NO synthesis.

Estriol-induced fibrinolysis due to the activation of plasminogen to plasmin by nitric oxide synthesis in platelets.

Estriol, an oestrogen, at 0.6 nmol/l was reported to inhibit ADP-induced platelet aggregation through nitric oxide synthesis. As nitric oxide has been reported to cause fibrinolysis due to the activation of plasminogen to plasmin, the role of estriol as a fibrinolytic agent was investigated. Also, the mechanism of estriol-induced nitric oxide synthesis in anucleated platelets was investigated. The estriol-induced lysis of platelet-rich plasma (PRP) clot was determined by photography of the clot lysis and by the assay of fibrin degradation products in the lysate and was obtained by SDS-PAGE. Nitric oxide was determined by methemoglobin method. The platelet membrane protein was isolated from the platelets by using Triton X-100 (0.05% v/v). The binding of estriol to the protein was determined by Scatchard plot by using an ELISA for estriol. Estriol at 0.6 nmol/l was found to lyse the clotted PRP due to fibrinolysis that produced fibrin degradation products in the lysate. The amino acid analysis of the platelet membrane protein, which resembles with nitric oxide synthase (NOS) activity, was activated nearly 10-fold over the control in the presence of estriol and was identified to be a human serum albumin precursor (Mr. 69 kDa) that binds to estriol with Kd1 of 6.0 × 10 mol/l and 39 ±â€Š2 molecules of estriol bound the NOS molecule. The estriol-induced nitric oxide is capable of inducing fibrinolysis of the clotted PRP. The binding of estriol to platelet membrane NOS activated the enzyme in the absence of DNA in the platelet.

Neutralization by "antineoplastin" of insulin-activated nitric oxide synthase antibody and its effects in cancers.

PURPOSE: The plasma level of nitric oxide (NO), that has been reported to possess various antineoplastic properties, was found to be diminished due to the impairment of insulin-activated nitric oxide synthase (IANOS) as a result of the appearance of a novel antibody (free light chain of IgG, M(r) 44 kD) against the enzyme in the circulation in various cancers compared to normal control. METHODS: We report here two NO-generating agents, antineoplastin I (a protein, M(r) 5000) and antineoplastin II (an inorganic compound), which when applied to the skin of cancer patients were capable of neutralizing the antibody in vivo through the production of NO in the skin cells due to the stimulation of membrane IANOS of these cells and, subsequently, in erythrocytes in the circulation. RESULTS: Neither antineoplastin I nor antineoplastin II itself enters into the circulation but due to the application of these agents on the skin, the NO synthesis in erythrocytes was normalized in these patients through "feedback" activation and amplification of IANOS activity by NO itself. CONCLUSION: It was found that the resumption of NO synthesis through the neutralization of antibody resulted in favorable modifications of various cancer-associated pathophysiologic consequences.

The role of inhibition of nitric oxide synthesis in the aggregation of platelets due to the stimulated production of thromboxane A2.

The aggregation of platelets by ADP is reported to be mediated through prostaglandin synthesis. In contrast, nitric oxide is known to inhibit platelet aggregation through the synthesis of cyclic AMP and cyclic GMP. Studies were conducted to determine the role of ADP, if any, on the synthesis of nitric oxide in platelets. Both normal male and female volunteers between the ages of 30 and 45 years participated in the study. Thromboxane A2 (TXA2) was measured as thromboxane B2 by ELISA. Nitric oxide was measured by methhaemoglobin method. It was found that the treatment of platelet-rich plasma (PRP) with different concentrations of ADP (0-8.0 µmol/l) resulted in increased platelet aggregation, and at 8.0 µmol/l ADP, the basal nitric oxide level was found to be maximally decreased from 0.3 ± 0.10 nmol/10 platelets to 0 nmol/10 platelets in PRP (P < 0.0001; n = 10). Line-weaver-Burk plot of nitric oxide synthase (NOS) activity in the presence of 2.0 µmol/l ADP reduced the Vmax from 6.662 to 2.22 nmol nitric oxide/h per mg protein compared with control. Inhibition of nitric oxide synthesis by N-methyl-L-arginine acetate ester (L-NAME), an inhibitor of NOS, was found to aggregate platelets due to the reduction of platelet nitric oxide level (Pearson's coefficient of correlation, r =  -0.986, P < 0.001, n = 10). The treatment of PRP to L-NAME was found to increase TXA2 synthesis to 1.679 ± 0.05 from 0 pmol/10 platelets. These results suggested that inhibition of NOS in platelets resulted in platelet aggregation through TXA2 synthesis in PRP through a novel pathway.

Effect of progesterone receptor status on maspin synthesis via nitric oxide production in neutrophils in human breast cancer.

BACKGROUND: Although progesterone receptor (PR) status, similarly to estrogen receptor status, is of prognostic importance in breast cancer, the involvement of the PR in breast cancer remains obscure. Studies were conducted to determine the function of the PR in neutrophils in the nitric oxide-induced synthesis of maspin, an anti-breast-cancer protein produced in nonmalignant mammary cells and in neutrophils in the circulation. METHODS: PR status was determined by immunohistochemistry. Maspin synthesis was determined by in-vitro translation of messenger RNA and quantified by enzyme-linked immunosorbent assay. Nitric oxide was determined by the methemoglobin method. RESULTS: It was found that PR status in neutrophils was identical with that in malignant breast tissues. A Scatchard plot for progesterone binding to normal and PR-positive (PR+) neutrophils revealed that whereas normal neutrophils had 11.5 × 10(10) PR sites/cell with K d = 47.619 nM, PR+ neutrophils had 6.6 × 10(10) PR sites/cell with K d = 47.619 nM. The progesterone negative (PR-) neutrophils failed to bind to progesterone. Incubation of normal and PR+ neutrophils with 25 nM progesterone produced 1.317 µM NO and 2.329 nM maspin; the PR+ neutrophils produced 0.72 µM NO and 1.138 nM maspin. The PR- neutrophils failed to produce any NO or maspin in the presence of progesterone. Inhibition of progesterone-induced NO synthesis led to complete inhibition of maspin synthesis in all neutrophils. CONCLUSION: These results suggest that estrogen and progesterone complement each other in NO-induced maspin synthesis, and do not necessarily antagonize in the synthesis of the anti-breast-cancer protein.

The activation by glucose of liver membrane nitric oxide synthase in the synthesis and translocation of glucose transporter-4 in the production of insulin in the mice hepatocytes.

INTRODUCTION: Glucose has been reported to have an essential role in the synthesis and secretion of insulin in hepatocytes. As the efflux of glucose is facilitated from the liver cells into the circulation, the mechanism of transportation of glucose into the hepatocytes for the synthesis of insulin was investigated. METHODS: Grated liver suspension (GLS) was prepared by grating intact liver from adult mice by using a grater. Nitric oxide (NO) was measured by methemoglobin method. Glucose transporter-4 (Glut-4) was measured by immunoblot technique using Glut-4 antibody. RESULTS: Incubation of GLS with different amounts of glucose resulted in the uptake of glucose by the suspension with increased NO synthesis due to the stimulation of a glucose activated nitric oxide synthase that was present in the liver membrane. The inhibition of glucose induced NO synthesis resulted in the inhibition of glucose uptake. Glucose at 0.02M that maximally increased NO synthesis in the hepatocytes led to the translocation and increased synthesis of Glut-4 by 3.3 fold over the control that was inhibited by the inhibition of NO synthesis. The glucose induced NO synthesis was also found to result in the synthesis of insulin, in the presence of glucose due to the expression of both proinsulin genes I and II in the liver cells. CONCLUSION: It was concluded that glucose itself facilitated its own transportation in the liver cells both via Glut-4 and by the synthesis of NO which had an essential role for insulin synthesis in the presence of glucose in these cells.

The role of dermcidin isoform 2: a two-faceted atherosclerotic risk factor for coronary artery disease and the effect of acetyl salicylic Acid on it.

Hypertension and diabetes mellitus are considered to be two major atherosclerotic risk factors for coronary artery disease (CAD). A stress-induced protein identified to be dermcidin isoform 2 of Mr. 11 kDa from blood plasma of hypertensive persons when injected (0.1 µM) in rabbits increased the systolic pressure by 77% and diastolic pressure by 45% over the controls within 2 h. Ingestion of acetyl salicylic acid (150 mg/70 kg) by these subjects reduced systolic (130 mm Hg) and diastolic pressures (80 mm Hg) with reduction of plasma dermcidin level to normal ranges (9 nM). The protein was found to be a potent activator of platelet cyclooxygenase and inhibited insulin synthesis. Aspirin was found to reduce hypertension by reduction of plasma dermcidin level, neutralized the effect of cyclooxygenase, and restored the pancreatic insulin synthesis through NO synthesis. These results indicated that dermcidin could be a novel atherosclerotic risk factor for its hypertensive and diabetogenic effects.

The Control of Stress Induced Type I Diabetes Mellitus in Humans through the Hepatic Synthesis of Insulin by the Stimulation of Nitric Oxide Production.

The role of stress induced development of Type-1 diabetes mellitus (T1DM) as opposed to autoimmunity remains obscure. It has been reported that a stress induced protein, identified to be dermcidin isoform 2 (dermcidin) inhibited insulin synthesis in both the pancreatic ß cells and the hepatic cells. As dermcidin effect could be neutralized by the increased production of systemic nitric oxide (NO), investigations were carried out to determine the feasibility of controlling stress induced T1DM through the neutralization of dermcidin by systemic increase of NO. To determine the role of plasma dermcidin level in T1DM subjects (n=45), if any, when the plasma dermcidin level were determined, it was found that the protein level was increased in 65% of the participating volunteers. Efforts were made to normalize the plasma glucose level (median=175 mg/dL) in these T1DM subjects by systemic increase of NO by applying a cotton pad containing 0.28mmol sodium nitroprusside on the abdominal skin. It was found that the systemic increase of NO level decreased the blood glucose level of 275 mg/dL (median) to 115 mg/dL (median) in these volunteers within 24 h with concomitant increase of plasma insulin level from 7.5 µunits/dL to 101 µunits/dL at the same time. The increase of plasma insulin level was accompanied by the decrease of dermcidin level of 124.5 nM to 18 nM with increase of NO from 0.43 ± 0.19 nM to 4.1 ± 1.56 nM. The results suggested that the stress induced T1DM by dermcidin could be controlled by the systemic increase of NO which in consequence led to increased synthesis of insulin.