dinoprost and Hyperplasia

Proliferation and migration of vascular smooth muscle cells (VSMCs) play pivotal roles in the development of restenosis after angioplasty and oxidative stress involves both processes. Naringenin, a flavanone compound found in citrus fruits, has been widely evaluated for antioxidant activity. This study was designed to explore whether naringenin could inhibit angiotensin II-induced VSMCs proliferation and migration and decrease neointimal hyperplasia in balloon injured rat carotid arteries. VSMCs were treated with or without naringenin before stimulation with 1 µM angiotensin II and twenty-four rats were subjected to carotid arteries injury and the carotid arteries were harvested at 14 d after balloon injury. The results showed naringenin led to a significant inhibition of angiotensin II-induced VSMCs proliferation and migration. Naringenin significantly attenuated the reactive oxygen species production, increased the superoxide dismutase activity and decreased the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity, reduced phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) and the nuclear translocation of nuclear factor (NF)-κB p65 in angiotensin II-treated VSMCs. Moreover, naringenin decreased the ratio of neointima to media by 63.8% in balloon injured rat carotid arteries, and the serum level of 8-iso-prostaglandin F2α in naringenin-treated rats was significantly decreased. These results indicated naringenin exhibited antioxidant activity on angiotensin II-treated VSMCs and balloon injured rat carotid arteries and could be a potential protective agent for restenosis after angioplasty.

Topics: Angiotensin II; Animals; Antioxidants; Carotid Arteries; Carotid Artery Injuries; Cell Proliferation; Citrus; Coronary Restenosis; Dinoprost; Flavanones; Hyperplasia; Male; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; NADPH Oxidases; Oxidative Stress; Phytotherapy; Plant Extracts; Protein Kinase Inhibitors; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Superoxide Dismutase; Transcription Factor RelA; Tunica Intima

Dietary advanced glycosylation end products (AGEs) have been linked to insulin resistance in db/db(++) mice. To test whether dietary AGEs play a role in the progression of insulin resistance in normal mice fed high-fat diets, normal C57/BL6 mice were randomly assigned to high-fat diets (35% g fat), either high (HAGE-HF group; 995.4 units/mg AGE) or low (by 2.4-fold LAGE-HF group; 329.6 units/mg AGE) in AGE content for 6 months. Age-matched C57/BL6 and db/db(++) mice fed regular diet (5% g fat, 117.4 units/mg AGE) served as controls. After 6 months, 75% of HAGE-HF mice were diabetic and exhibited higher body weight (P < 0.001), fasting glucose (P < 0.001), insulin (P < 0.001), and serum AGEs (P < 0.01) than control mice, while none of the LAGE-HF mice were diabetic despite a similar rise in body weight and plasma lipids. The HAGE-HF group displayed markedly impaired glucose and insulin responses during glucose tolerance tests and euglycemic and hyperglycemic clamps and altered pancreatic islet structure and function compared with those of LAGE-HF mice, in which findings resembled those of control mice. The HAGE-HF group had more visceral fat (by two- and fourfold) and more AGE-modified fat (by two- and fivefold) than LAGE-HF and control mice, respectively. In the HAGE-HF group, plasma 8-isoprostane was higher (P < 0.01) and adiponectin lower (P < 0.001) than control mice, while in the LAGE-HF group, these were more modestly affected (P < 0.05). These results demonstrate that the development of insulin resistance and type 2 diabetes during prolonged high-fat feeding are linked to the excess AGEs/advanced lipoxidation end products inherent in fatty diets.

Topics: Adiponectin; Adipose Tissue; Animals; Blood Glucose; Body Weight; Diabetes Mellitus, Type 2; Dietary Fats; Dinoprost; Fasting; Female; Glucose Clamp Technique; Glucose Tolerance Test; Glycation End Products, Advanced; Hyperplasia; Insulin; Insulin Resistance; Intercellular Signaling Peptides and Proteins; Islets of Langerhans; Lipids; Mice; Mice, Inbred C57BL

The role of enteral or parenteral long-chain triacylglycerol (LCT) in the complex process of intestinal adaptation is poorly defined and may involve alterations in eicosanoid synthesis. Our objective was to determine whether provision of parenteral LCT stimulates eicosanoid synthesis and resection-induced intestinal adaptation. We assessed small bowel structural adaptation, the fatty acid profiles of liver, plasma and jejunal mucosa, and the profile of 11 eicosanoids derived from (n-6) PUFA of the jejunal mucosa in rats maintained with total parenteral nutrition (TPN) with 0 or 32% of nonprotein energy from Intralipid for 7 d after mid-small bowel resection or transection control surgery. There was no evidence of biochemical essential fatty acid (EFA) deficiency in the absence of parenteral fat. Resection-induced gut growth occurred independently of parenteral LCT based on significant mucosal hyperplasia in the jejunum and ileum. The mucosal profile of linoleic acid in the total lipid extract of jejunum increased with the presence of parenteral LCT, but decreased with resection without differences in arachidonic acid. There were no differences in the jejunal profile of 11 (n-6)-derived eicosanoids among the four TPN groups as determined by tandem MS. In summary, small bowel resection-induced adaptation occurs independently of parenteral LCT, and fat-free TPN without EFA deficiency does not alter the profile of jejunal (n-6)-derived eicosanoids. Thus, parenteral administration of LCT does not appear to alter jejunal eicosanoid synthesis nor is it beneficial in stimulating intestinal adaptation.

Topics: Adaptation, Physiological; Dietary Fats; Dinoprost; Dinoprostone; Eicosanoids; Fatty Acids; Hyperplasia; Ileum; Intestinal Mucosa; Intestine, Small; Intestines; Jejunum; Linoleic Acid; Lipids; Liver; Oleic Acid; Palmitic Acid; Parenteral Nutrition, Total; Triglycerides; Weight Gain

Prostaglandin formation is enhanced in vascular disease, in part through induction of cyclooxygenase (COX-2) in vascular smooth muscle cells. Because COX regulates cell growth and migration, we examined whether the COX expression plays a role in the development of intimal hyperplasia after vascular injury. Rats undergoing balloon angioplasty of the carotid artery were randomized to receive a selective COX-2 inhibitor (SC-236), a selective COX-1 inhibitor (SC-560) or a combination of the two. Normal, uninjured vessels showed COX-1, but no COX-2 expression. Fourteen days after balloon injury, both COX-1 and COX-2 were expressed in the neointima. Balloon angioplasty resulted in a marked increase in the urinary excretion of prostaglandin (PG) E(2,) PGF(2alpha), and thromboxane (TX) B(2). Both the COX-1 inhibitor SC-560 and the COX-2 inhibitor SC-236 suppressed the generation of PGE(2) and PGF(2alpha), particularly when combined, suggesting a role for both isozymes in the generation of prostaglandins in this model. In contrast, TXA(2) was markedly suppressed by the COX-1 inhibitor SC-560. COX-2 inhibition with SC-236 had no effect on intimal hyperplasia at day 14 (0 versus 8.5%; n = 7 in controls). In contrast, intimal hyperplasia was reduced by SC-560 when administered alone (by 42%; n = 7, p < 0.05) or in combination with SC-236 (by 40%; n = 7, p < 0.05). COX-1 may play a role in the development of intimal hyperplasia, potentially through the inhibition of platelet TXA(2). Despite being expressed in the neointima, COX-2 does not play a role in the development of intimal hyperplasia after vascular injury.

Topics: Angioplasty, Balloon; Animals; Carotid Arteries; Cyclooxygenase 1; Dinoprost; DNA Primers; Eicosanoids; Graft Occlusion, Vascular; Hyperplasia; Immunohistochemistry; Isoenzymes; Male; Membrane Proteins; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; Thromboxane B2; Tunica Intima

Hyperlipidemia may increase endothelial damage and promote accelerated atherogenesis in graft coronary vasculopathy. To study the effects of hypercholesterolemia on coronary endothelial dysfunction, intimal hyperplasia, and lipid content, a porcine model of heterotopic heart transplantation, allowing nonacute rejection without immunosuppressive drugs, was used. A high cholesterol diet was fed to donor and recipient swine 1 month before and after transplantation. The endothelial function of coronary arteries of native and transplanted hearts from cholesterol-fed animals was studied in organ chambers 30 days after implantation and compared with endothelial function in arteries from animals fed a normal diet. The total serum cholesterol increased 3-fold in donors and recipients. Endothelium-dependent relaxations to serotonin, to the alpha(2)-adrenergic agonist UK14,304, and to the direct G-protein activator sodium fluoride were decreased significantly in allografted hearts compared with native hearts from both groups. Relaxations to the calcium ionophore A23187 and bradykinin were decreased significantly in allografts from animals fed the high cholesterol diet. The prevalence of intimal hyperplasia was significantly increased in coronary arteries from hypercholesterolemic swine. There was a significant increase in the lipid content of allograft arteries of hypercholesterolemic recipients. Hypercholesterolemia causes a general coronary endothelial dysfunction, increases the prevalence of intimal hyperplasia, and augments the incorporation of lipids in the vascular wall after heart transplantation. Hyperlipidemia accelerates graft coronary atherosclerosis through its effects on the endothelium.

Topics: Adrenergic alpha-Agonists; Animals; Arteriosclerosis; Biological Transport; Brimonidine Tartrate; Calcimycin; Calcium; Cholesterol, HDL; Cholesterol, LDL; Coronary Vessels; Diet, Atherogenic; Dinoprost; Dose-Response Relationship, Drug; Endothelium, Vascular; Erythrocyte Count; Female; Free Radical Scavengers; Heart Transplantation; Hematocrit; Hemoglobins; Hypercholesterolemia; Hyperplasia; Ionophores; Male; Myocardium; Postoperative Period; Potassium Chloride; Quinoxalines; Serotonin; Swine; Transplantation, Homologous; Tunica Intima; Vasodilation

Reverse transcription polymerase chain reaction (RT-PCR) and Northern blot analysis was used to determine the level of expression of prostaglandin F(2alpha) (FP) receptor mRNA in various mouse tissues, including normal, hyperplastic and neoplastic mouse epidermis. Steady-state concentrations of FP receptor mRNA were low in normal and hyperplastic epidermis. The response of the epidermis to the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) was biphasic in that FP receptor mRNA was increased immediately after treatment, followed by a long-lasting down-regulation at later time points. FP receptor mRNA was down-regulated in the majority of papillomas obtained by the mouse skin carcinogenesis initiation-promotion protocol. In carcinomas, FP receptor mRNA expression was similar to that in normal epidermis. The steady-state concentration of FP mRNA was inversely correlated with PGF(2alpha) levels in normal and hyperplastic epidermis and in papillomas, indicating that FP mRNA expression is regulated by this eicosanoid.

Topics: Adolescent; Animals; Base Sequence; Carcinogens; Dinoprost; DNA Primers; Female; Humans; Hyperplasia; Mice; Polymerase Chain Reaction; Receptors, Prostaglandin; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate

The effects of CV-11974, a potent nonpeptide antagonist of the angiotensin II (AII) type-1 receptor (AT1), on cytosolic free calcium concentration ([Ca2+]i), hyperplasia, and hypertrophy of cultured vascular smooth muscle cells (VSMC) from rat aorta were studied. [Ca2+]i was measured by fura 2, and hyperplasia and hypertrophy were determined by incorporation of [3H]thymidine and [3H]leucine, respectively. CV-11974 had no effect on [Ca2+]i itself, but suppressed 10(-7) M AII-induced increase in [Ca2+]i dose dependently at concentrations from 10(-10) M and completely at 10(-7) M. CV-11974 suppressed both Ca2+ release from intracellular Ca2+ stores and Ca2+ influx from the extracellular space. However, CV-11974 had no effect on the increases in [Ca2+]i induced by prostaglandin F2 alpha (PGF2 alpha), a potent vasoconstrictor, or ionomycin, a Ca2+ ionophore. These results indicate that the suppressive effects of CV-11974 act on the binding of AII and its specific receptors. AII 10(-7) M increased the synthesis of DNA and protein to 1.5 and 1.7 times the control values, respectively. CV-11974 had no effect on synthesis of DNA or protein, but suppressed the AII-stimulated synthesis of DNA and protein dose dependently at concentrations > or = 10(-8) and 10(-10) M, respectively and completely at 10(-6) M. These results indicate that AII increases [Ca2+]i and synthesis of DNA and protein in VSMC through activation of AT1. CV-11974 showed no partial agonistic effects on AII. Thus, CV-11974 may act not only as an antihypertensive agent, but also as an inhibitor of vascular injury stimulated by AII.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Animals; Aorta, Thoracic; Benzimidazoles; Biphenyl Compounds; Calcium; Cells, Cultured; Cytosol; Dinoprost; DNA; Fura-2; Hyperplasia; Hypertrophy; Ionomycin; Muscle Proteins; Muscle, Smooth, Vascular; Rats; Rats, Wistar; Tetrazoles

Experiments were designed to determine the effects of blood flow on endothelium-dependent relaxations in canine vein grafts.. Blood flow through reversed femoral vein grafts was either increased by a distal arteriovenous fistula (increased flow), unmanipulated (normal flow), or reduced by a proximal adjustable clamp (reduced flow). Six weeks after implantation, blood flow through the graft was measured. Rings cut from grafts were suspended for the measurement of isometric force in organ chambers to determine endothelial function.. Blood flow was significantly greater in grafts with a distal fistula compared to grafts with normal or decreased flow. Endothelium-dependent relaxations to acetylcholine were absent in all grafts. Endothelium-dependent relaxations to adenosine diphosphate, thrombin, and the calcium ionophore A23187 were less in grafts with reduced flow compared with grafts with increased flow. Relaxations to these agents in grafts with increased flow were reduced by an analog of L-arginine. Neointimal hyperplasia was increased in grafts with reduced flow.. These data demonstrate that chronic diminution of blood flow decreases receptor-mediated release of endothelium-derived relaxing factors and increases neointimal hyperplasia in canine vein grafts. The production of endothelium-derived relaxing factors, one of which is nitric oxide, may influence the development of myointimal hyperplasia in vein grafts.

Topics: Acetylcholine; Adenosine Diphosphate; Adrenergic alpha-Agonists; Animals; Arginine; Arteriovenous Shunt, Surgical; Blood Flow Velocity; Brimonidine Tartrate; Calcimycin; Constriction; Dinoprost; Dogs; Endothelins; Endothelium, Vascular; Femoral Artery; Femoral Vein; Hyperplasia; Male; Models, Biological; Neovascularization, Pathologic; Nitric Oxide; omega-N-Methylarginine; Quinoxalines; Thrombin; Tunica Intima; Vascular Patency

We examined physiological events in the hyperplastic artery, using a method based on the mechanical responsiveness and myosin light-chain phosphorylation in response to various stimulants. Six weeks after endothelial denudation by ballooning of the right carotid artery, strips of this artery with moderate intimal hyperplasia (intimal area was 30-50% of medial area in 20 of 28 rabbits) were used for experiments. Strips from the left carotid served as the normal control. When the hyperplastic artery was stimulated with 30 microM PGF2 alpha, the maximal tension (232.4 +/- 49.1 mg/mg dry wt, mean +/- SD) was significantly higher (P < 0.05) than that of the control (129.5 +/- 16.4 mg/mg). The maximal extent of myosin light-chain monophosphorylation (45.4 +/- 8.9%) and diphosphorylation (10.9 +/- 5.2%) in the hyperplastic artery was significantly higher (P < 0.05) than that in the control artery (33.0 +/- 4.8 and 4.0 +/- 4.8%, respectively). The monophosphorylation of the myosin light chain in the hyperplastic artery was sustained for up to 20 min, while that in the control artery decreased to the basal level within 20 min. Similar observations were obtained by stimulation with 60 mM K+ or 30 microM norepinephrine. Dose-response curves of the development of tension in the hyperplastic artery to various agonists (K+, PGF2 alpha, norepinephrine) shifted upward the curves for the control artery. These results suggest that qualitative changes in the characteristics of smooth muscle cells may occur in the intimal hyperplastic portion, including a hyperreactive contraction associated with enhanced and sustained phosphorylation of the myosin light chain.

Topics: Animals; Calcium; Carotid Arteries; Dinoprost; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Hyperplasia; Male; Microscopy, Electron, Scanning; Muscle Contraction; Muscle, Smooth, Vascular; Myosins; Norepinephrine; Phosphorylation; Potassium; Rabbits; Tunica Intima

Topics: Calcimycin; Cell Division; Cocarcinogenesis; Dinoprost; Dinoprostone; Epidermal Cells; Hyperplasia; Indomethacin; Prostaglandins E; Prostaglandins F; Skin; Skin Neoplasms; Structure-Activity Relationship; Tetradecanoylphorbol Acetate