Physiological and metabolic functions of the β-adrenergic receptor and an approach to therapeutic achievements.

A specific type of beta-adrenergic receptor was discovered in the decade of 1980s and subsequently recognized as a new type of beta-adrenergic receptor, called beta-adrenoceptor (β-AR). β-AR expresses in different tissues, including adipose tissue, gall bladder, stomach, small intestine, cardiac myocytes, urinary bladder, and brain. Structurally, β-AR is very similar to β- and β-AR and belongs to a G-protein coupled receptor that uses cAMP as an intracellular second messenger.

Effects of p-synephrine alone and in combination with selected bioflavonoids on resting metabolism, blood pressure, heart rate and self-reported mood changes.

Bitter orange (Citrus aurantium) extract is widely used in dietary supplements for weight management and sports performance. Its primary protoalkaloid is p-synephrine. Most studies involving bitter orange extract and p-synephrine have used products with multiple ingredients.

Comparative effects of selected non-caffeinated rehydration sports drinks on short-term performance following moderate dehydration.

Background: The effect of moderate dehydration and consequent fluid replenishment on short-duration maximal treadmill performance was studied in eight healthy, fit (VO2max = 49.7 +/- 8.7 mL kg-1 min-1) males aged 28 +/- 7.

Inhibition of Helicobacter pylori in vitro by various berry extracts, with enhanced susceptibility to clarithromycin.

The objective of this study was to evaluate the effects of various berry extracts, with and without clarithromycin on Helicobacter pylori. Resistance to clarithromycin by H. pylori has been reported, leading to interest in alternatives/adjuncts to therapy with clarithromycin.

The bactericidal effects of Lactobacillus acidophilus, garcinol and Protykin compared to clarithromycin, on Helicobacter pylori.

Chronic infection with Helicobacter pylori causes peptic ulcers, gastric cancer and lymphoma. We evaluated the inhibitory effects of the probiotic Lactobacillus acidophilus DDS-1J, the antibiotic clarithromycin and the natural antioxidants garcinol and Protykin (containing 50% trans-resveratrol) on Helicobacter pylori strain ATCC 49503. The findings of this study indicate that Lactobacillus acidophilus DDS-1J exerts a growth inhibitory effect on H.

Helicobacter pylori-induced oxidative stress and DNA damage in a primary culture of human gastric mucosal cells.

Helicobacter pylori has been identified in the pathogenesis of chronic active gastritis and peptic ulcer disease and is epidemiologically linked to gastric cancer and lymphoma. Our previous studies have demonstrated enhanced production of reactive oxygen species (ROS) in cultured gastric adenocarcinoma cells (ATCC CRL/1739) in association with H. pylori.

Mechanism of gastroprotection by bismuth subsalicylate against chemically induced oxidative stress in cultured human gastric mucosal cells.

Reactive oxygen species (ROS) are implicated in the pathogenesis of chemically induced gastric mucosal injury. We have investigated the effects of ethanol, hydrochloric acid (HCl), and sodium hydroxide (NaOH) on: (1) enhanced production of ROS including superoxide anion and hydroxyl radicals, (2) modulation of intracellular oxidized states by laser scanning confocal microscopy, and (3) DNA fragmentation, indices of oxidative tissue, and DNA damage in a primary culture of normal human gastric mucosal cells (GC), which were isolated and cultured from Helicobacter pylori-negative endoscopic biopsies from human subjects. The induction of ROS and DNA damage in these cells following exposure to ethanol (15%), HCl (150 mM) and NaOH (150 mM) were assessed by cytochrome c reduction (superoxide anion production), HPLC detection for enhanced production of hydroxyl radicals, changes in intracellular oxidized states by laser scanning confocal microscopy, and DNA damage by quantitating DNA fragmentation.

Induction of oxidative stress and DNA damage by chronic administration of naphthalene to rats.

Naphthalene is a bicyclic aromatic compound that is widely used in various domestic and commercial applications including lavatory scent disks, soil fumigants and moth balls. Little information is available regarding the mechanism of naphthalene toxicity. We have assessed the oral, low dose (0.

Role of intracellular calcium in peroxide-induced potentiation of norepinephrine release from bovine isolated irides.

1. BAPTA AM (10 microM), thapsigargin (10 microM), ruthenium red (30 microM) and oligomycin (30 microM) inhibited field-stimulated [3H]NE release from bovine isolated irides by 54%, 30%, 30% and 26%, respectively. 2.

Prejunctional alpha2-adrenoceptors and peroxide-induced potentiation of norepinephrine release from the bovine iris.

Peroxides can enhance field-stimulated [3H]norepinephrine ([3H]NE) release in isolated irides from several mammalian species. In the present study, we investigated the role of prejunctional alpha2-adrenoceptors in peroxide-induced potentiation of sympathetic neurotransmission in bovine isolated irides. Isolated hemi-irides were incubated in a Krebs buffered-solution containing [3H]NE and prepared for studies of neurotransmitter release using the superfusion method.

Subchronic effects of smokeless tobacco extract (STE) on hepatic lipid peroxidation, DNA damage and excretion of urinary metabolites in rats.

The oral use of moist smokeless tobacco products (snuff) is causally associated with cancer of the mouth, lip, nasal cavities, esophagus and gut. The mechanism by which smokeless tobacco constituents produce genetic and tissue damage is not known. Recent studies in our laboratories have shown that an aqueous extract of smokeless tobacco (STE) activates macrophages with the resultant production of reactive oxygen species (ROS), including nitric oxide.

Mechanism of peroxide-induced potentiation of sympathetic neurotransmission in bovine irides: role of extracellular calcium.

Hydrogen peroxide (H2O2) and enzymes that regulate its metabolism are present in tissues of the anterior segment of the eye. We have previously shown that in vitro, H2O2 can enhance sympathetic neurotransmission in irides from several mammalian species. In the present study, we investigated the role of extracellular calcium in H2O2-induced potentiation of sympathetic neurotransmission in the bovine isolated iris.

Naphthalene-induced oxidative stress and DNA damage in cultured macrophage J774A.1 cells.

Naphthalene is a bicyclic aromatic compound that is widely used in various domestic and commercial applications including lavatory scent disks, soil fumigants and moth balls. However, little information is available regarding the mechanism of naphthalene toxicity. We have assessed the concentration-dependent in vitro effects of naphthalene on increased lipid peroxidation, cytochrome c reduction, hydroxyl radical production, modulation of intracellular oxidized states by laser scanning confocal microscopy, and DNA fragmentation in cultured macrophage J774A.

In vitro effects of smokeless tobacco extract on tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) production, and on lymphocyte proliferation.

The use of smokeless tobacco (moist snuff) products is associated with mucosal lesions, gingival recession, attachment loss, and oral cancer. Despite numerous reports on the general toxic effects of smokeless tobacco extract, little information is available regarding the specific effects of smokeless tobacco on immune response. Inflammatory cytokines released as a result of smokeless tobacco-induced irritation may play a role in the development of oral mucosal lesions at habitual tobacco placement sites in smokeless tobacco users.

The profile of the cytokines secreted during the generation of T-helper cells from atopic asthmatic subjects.

This study investigated cytokine release by T-cell lines from atopic and nonatopic individuals in the presence of specific aeroallergen. Cell lines from atopic and nonatopic individuals secreted IL-2 for less than 14 and more than 21 days, respectively. All of the atopic, but not the nonatopic, cell lines exhibited a biphasic peak in IL-4 and IL-5 secretion.

Stress, diet and alcohol-induced oxidative gastrointestinal mucosal injury in rats and protection by bismuth subsalicylate.

Oxygen free radicals are implicated in the pathogenesis of stress and food/alcohol-induced gastrointestinal injury. We have investigated the effects of restraint stress, spicy food diet, high-fat diet and 40% ethanol on the enhanced production of reactive oxygen species, including superoxide anion and hydroxyl radicals, and on DNA fragmentation, lipid peroxidation and membrane microviscosity (indices of oxidative tissue damage) in gastric and intestinal mucosa of Sprague-Dawley rats. Furthermore, the protective ability of bismuth subsalicylate (BSS; 15 mg kg(-1) was determined against the gastrointestinal mucosal injury induced by these stressors.

Bicyclic derivatives of hexahydroaporphine: novel agents that lower intraocular pressure.

We have synthesized a number of novel bicyclic hexahydroaporphines containing a phenethylamine moiety for preliminary study as intraocular pressure lowering agents. The target molecules were synthesized in a twelve step process. The final products were secondary or tertiary amines containing either an aromatic methoxy or phenolic substituent.

Role of cyclic AMP in hydrogen peroxide-induced potentiation of sympathetic neurotransmission in the bovine iris.

Hydrogen peroxide (H2O2) has been shown to enhance electrically-evoked norepinephrine (NE) release from isolated, superfused bovine irides. Since stimulation of presynaptic adenylyl cyclase can potentiate sympathetic neurotransmission in several tissues, the present study considered the possibility that cyclic AMP may mediate the effects of H2O2 in the iris. Isolated bovine irides were prepared for analysis of field stimulation-induced [3H]NE release using the superfusion method.

Comparative in vitro oxygen radical scavenging ability of zinc methionine and selected zinc salts and antioxidants.

1. The concentration-dependent scavenging abilities of zinc DL-methionine, zinc sulfate, zinc gluconate, zinc picolinate and selected free radical scavengers, including superoxide dismutase (SOD), catalase, mannitol, allopurinol and DL-methionine, were examined against biochemically generated superoxide anion, hydroxyl radical and hypochlorite radical plus hypochlorous acid, by chemiluminescence and cytochrome c reduction. 2.

Cadmium-induced production of superoxide anion and nitric oxide, DNA single strand breaks and lactate dehydrogenase leakage in J774A.1 cell cultures.

The involvement of reactive oxygen species in the toxicity of cadmium (Cd) has been proposed. We have, therefore, examined the effects of this cation on the production of superoxide anion and nitric oxide and DNA single strand breaks in J774A.1 macrophage cells in culture as well as the effects on lactate dehydrogenase (LDH) leakage and cell viability.

Role of iron in ricin-induced lipid peroxidation and superoxide production.

Ricin has been shown to induce oxidative stress in the livers of mice in vivo. These studies examined ricin-induced hepatic microsomal lipid peroxidation in mice, and the modulation thereof by iron and desferrioxamine. In addition, the studies investigated the production of superoxide anion by microsomes, mitochondria, and macrophages.

Phosphodiesterase inhibitors suppress proliferation of peripheral blood mononuclear cells and interleukin-4 and -5 secretion by human T-helper type 2 cells.

It has been suggested that interleukin-4 and -5 (IL-4 and IL-5) are instrumental in the control of allergic disease. Elevated levels of IL-4 messenger RNA (mRNA) have been detected in numerous foci of atopic activity, including bronchoalveolar lavage (BAL) fluid from atopic asthmatics and skin of atopic dermatitis patients. IL-5 is important in eosinophil activation, which is a common feature of atopic disease.

In vitro effects of a smokeless tobacco extract on the production of reactive oxygen species by human oral epidermal cells and rat hepatic mitochondria and microsomes, and peritoneal macrophages.

The possible role of reaction oxygen species in the toxicity of smokeless tobacco was explored. In order to determine possible sources of reactive oxygen species in response to smokeless tobacco, rat peritoneal macrophages (3 x 10(6)/ml) and hepatic mitochondria and microsomes (1 mg protein/ml) from untreated female Sprague-Dawley rats were incubated with an aqueous smokeless tobacco extract (STE) (200 micro g/ml). STE resulted in rapid increases in chemiluminescence with maximum increases occurring at approximately 6 min for the macrophages and 8 min for mitochondria and microsomes.

Naphthalene-induced oxidative stress in rats and the protective effects of vitamin E succinate.

Quinone metabolites of naphthalene (NAP) are known to produce lipid peroxidation. However, the ability of naphthalene to induce oxidative stress in experimental animals has not been extensively investigated. Furthermore, the effects of vitamin E succinate [(+)-alpha-tocopherol acid succinate; VES] on naphthalene-induced oxidative stress and tissue damage were assessed.