Vasoconstrictor Effects of Trace Amine-Associated Receptor Agonists in the Isolated Perfused Rat Kidney.

Introduction: Endogenous trace amines such as tryptamine and 3-iodothyronamine (T1AM) are present in mammalian tissues at very low concentrations. They produce their actions by activating surface G protein-coupled receptors known as trace amine-associated receptors (TAARs).

Objective: The study was designed to investigate the possible vasoconstrictor effects of tryptamine, T1AM, and the selective TAAR1 agonist RO5263397 in isolated perfused rat kidney.

Vasodilator Effect of Trace Amines, 3-Iodothyronamine, and RO5263397 in the Rat Perfused Kidney: Comparison with Tryptamine.

Introduction: Trace amine-associated receptors (TAARs) are a family of G protein-coupled receptors and are widely distributed in the body. Activation of TAAR1 by specific agonists can produce a variety of physiological effects centrally and peripherally. The objective of this study was to investigate the vasodilator effect of two selective TAAR1 agonists 3-iodothyronamine (T1AM) and RO5263397 in the isolated perfused rat kidney preparation.

Role of Extracellular Calcium and Calcium Sensitization in the Anti-Contractile Effect of Perivascular Adipose Tissue in Pregnant Rat Aorta.

Previous studies have shown that the anti-contractile effect of the perivascular adipose tissue (PVAT) is attenuated in pregnancy. In the present investigation, we have examined the possibility that this loss of anti-contractile effect could be due to changes in calcium mobilization. PVAT exerted anti-contractile effect against 5-hydroxytryptamine (5-HT)-induced contractions of aorta segments from pregnant and non-pregnant rats and this anti-contractile effect was attenuated in segments from pregnant rats.

Attenuation of the anti-contractile effect of cooling in the rat aorta by perivascular adipose tissue.

In addition to providing mechanical support for blood vessels, the perivascular adipose tissue (PVAT) secretes a number of vasoactive substances and exerts an anticontractile effect. The main objective of this study was to find out whether the anticontractile effect of cooling in the rat aorta is affected by PVAT. Our hypothesis was that PVAT would enhance the anticontractile effect of cooling in the rat aorta.

The effect of sphingosine-1-phosphate on colonic smooth muscle contractility: Modulation by TNBS-induced colitis.

Aim: Increased levels of circulating sphingosine-1-phosphate (S1P) have been reported in ulcerative colitis. The objective of this study was to examine the effect of S1P on colonic smooth muscle contractility and how is it affected by colitis.

Methods: Colonic inflammation was induced by intrarectal administration of trinitrobenzene sulfonic acid.

Antihyperalgesic Activities of Endocannabinoids in a Mouse Model of Antiretroviral-Induced Neuropathic Pain.

Nucleoside reverse transcriptase inhibitors (NRTIs) are the cornerstone of the antiretroviral therapy for human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS). However, their use is sometimes limited by the development of a painful sensory neuropathy, which does not respond well to drugs. Smoked cannabis has been reported in clinical trials to have efficacy in relieving painful HIV-associated sensory neuropathy.

Rate of Homologous Desensitization and Internalization of the GLP-1 Receptor.

The glucagon-like peptide-1 receptor (GLP-1R) is an important target in the treatment of type 2 diabetes mellitus. The aim of this study was to compare the rate of agonist stimulated desensitization and internalization of GLP-1R. To this end, an N-terminally myc-tagged GLP-1R was stably expressed in HEK-293 cells.

Loss of Anticontractile Effect of Perivascular Adipose Tissue on Pregnant Rats: A Potential Role of Tumor Necrosis Factor-α.

The present investigation examined the effect of pregnancy on the anticontractile effect of perivascular adipose tissue (PVAT) on the rat. Ring segments of the aorta, with and without PVAT, were set up in organ baths for isometric tension recording. In both groups, concentration-response curves to 5-hydroxytryptamine (5-HT) were displaced to the right with a reduction of the maximum response in aorta segments with PVAT.

Cyclic Adenosine Monophosphate-Mediated Enhancement of Vascular Endothelial Growth Factor Released by Differentiated Human Monocytic Cells: The Role of Protein Kinase A.

Objective: Our investigation was designed to examine the signaling pathway involved in the enhancement of vascular endothelial growth factor (VEGF) release by β-adrenoceptor agonists.

Materials And Methods: Human U937 cells differentiated into macrophages were primed with lipopolysaccharide (LPS) in the absence or presence of β-adrenoceptor agonists and antagonists. The VEGF released and the intracellular cyclic adenosine monophosphate (cAMP) generated were assayed by ELISA.

Molecular basis for the effects of zinc deficiency on spermatogenesis: An experimental study in the Sprague-dawley rat model.

Introduction: The objective of this study is to investigate the molecular mechanisms underlying the effects of zinc deficiency on spermatogenesis in the Sprague-Dawley (SD) rat.

Materials And Methods: Three groups of eight adult male SD rats were maintained for 4 weeks on a normal diet as control, zinc deficient diet and zinc deficient diet with zinc supplementation of 28 mg zinc/kg body weight respectively. Using standard techniques, the following parameters were compared between the three groups of experimental animals at the end of 4 weeks: (a) Serum zinc, magnesium (Mg), copper (Cu), selenium (Se) and cadmium (Cd), (b) serum sex hormones, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPX), (c) interleukin-4 (IL-4), tumor necrosis factor-alpha (TNF-α), Bcl-2, Bax and caspase-3 expression in the testes, (d) assessment of apoptosis of testicular cells using electron microscopy and (e) testicular volume and histology using the orchidometer and Johnsen score, respectively.

Perivascular adipose tissue, vascular reactivity and hypertension.

Most blood vessels are surrounded by a variable amount of adventitial adipose tissue, perivascular adipose tissue (PVAT), which was originally thought to provide mechanical support for the vessel. It is now known that PVAT secretes a number of bioactive substances including vascular endothelial growth factor, tumor necrosis factor-alpha (TNF-α), leptin, adiponectin, insulin-like growth factor, interleukin-6, plasminogen activator substance, resistin and angiotensinogen. Several studies have shown that PVAT significantly modulated vascular smooth muscle contractions induced by a variety of agonists and electrical stimulation by releasing adipocyte-derived relaxing (ADRF) and contracting factors.

Late administration of Mn porphyrin-based SOD mimic enhances diabetic complications.

Mn(III) N-alkylpyridylporphyrins (MnPs) have demonstrated protection in various conditions where increased production of reactive oxygen/reactive nitrogen species (ROS/RNS), is a key pathological factors. MnPs can produce both pro-oxidative and antioxidative effects depending upon the cellular redox environment that they encounter. Previously we reported (Free Radic.

Expression of alternatively spliced variants of Na-Ca-exchanger-1 in experimental colitis: role in reduced colonic contractility.

Inflammation-induced colonic motility dysfunction is associated with a disturbance in Ca(2+) ion transporting mechanisms. The main objective of this study was to identify the types of Na-Ca-exchanger-1 (NCX-1) variants expressed in the rat colon, and how this was affected by colitis. In addition, the effect of colitis on the possible involvement of NCX-1 in the reduced carbachol-induced contraction of the rat colon was examined.

TH-9 (a theophylline derivative) induces long-lasting enhancement in excitatory synaptic transmission in the rat hippocampus that is occluded by frequency-dependent plasticity in vitro.

Dementia, especially Alzheimer's disease, is a rapidly increasing medical condition that presents with enormous challenge for treatment. It is characterized by impairment in memory and cognitive function often accompanied by changes in synaptic transmission and plasticity in relevant brain regions such as the hippocampus. We recently synthesized TH-9, a conjugate racetam-methylxanthine compound and tested if it had potential for enhancing synaptic function and possibly, plasticity, by examining its effect on hippocampal fast excitatory synaptic transmission and plasticity.

Colonic inflammation increases the contribution of muscarinic M2 receptors to carbachol-induced contraction of the rat colon.

Objectives: Carbachol-induced contraction of the rat colon is impaired in rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis. The main objective of this study was to examine the effect of colitis on the expression and function of muscarinic (M) receptor subtypes in the rat colon.

Materials And Methods: Rats (n = 80) were treated with TNBS and used 5 days later for measurement of contractility, myeloperoxidase activity, histology and expression of muscarinic receptor isoforms using Western blot analysis.

Hyperthyroidism enhances 5-HT-induced contraction of the rat pulmonary artery: role of calcium-activated chloride channel activation.

Experimentally-induced hyperthyroidism in rodents is associated with signs and symptoms of pulmonary hypertension. The main objective of the present study was to investigate the effect of thyroxine-induced pulmonary hypertension on the contractile response of the pulmonary artery to 5-HT and the possible underlying signaling pathway. 5-HT concentration-dependently contracted artery segments from control and thyroxine-treated rats with pD(2) values of 5.

Lithium protects against toxic effects of cadmium in the rat testes.

Purpose: To investigate the protective effect of Lithium against the toxic effect of Cadmium in the rat testes.

Methods: Twenty four adult male Sprague-Dawley rats were treated with four different regimens: Cadmium only, Cadmium and lithium, lithium only and controls. Rats were sacrificed after 6 weeks and testicular levels of pro-inflammatory cytokine (IL-4), anti-inflammatory cytokine (TNF-α), Pro-apoptotic protein (Bax) and anti-apoptotic protein (Bcl-2) were measured by ELISA while serum levels of FSH, LH, Prolactin and Testosterone were measured using the Vidas parametric system.

Curcumin attenuates inflammation through inhibition of TLR-4 receptor in experimental colitis.

Curcumin, an active ingredient of Curcumin longa mediates its anti-inflammatory effects through inhibition of NFkB. Several pathways including toll-like receptors (TLR) induce NFkB leading to inflammation. In this study, we investigated the effects of curcumin on the expression of TLR-4 and MyD88, the upstream signaling pathway in experimental colitis induced in the Sprague-Dawley male rats by intra-rectal administration of trinitrobenzenesulfonic acid (TNBS).

In vivo and in vitro assessment of human saphenous vein wall changes.

Purpose: To investigate if noradrenaline (NA) and 5-hydroxyptamine (5-HT) drugs induce responses of isolated control and varicose veins are altered by removal of the endothelium. SUBJECTS #ENTITYSTARTX00026;

Methods: Specimens of the great saphenous vein (GSV) were obtained from 12 subjects with primary varicose veins and 12 subjects from donor vessels at cardiac surgery. A total of 10 normal healthy volunteers were selected for comparison.

Curcumin reverses attenuated carbachol-induced contraction of the colon in a rat model of colitis.

Background: Curcumin ameliorates colitis whether it reverses colitis-induced reduction in colonic contractility remains to be investigated.

Objectives: To investigate the effect of curcumin on colitis-induced reduction of carbachol-induced contraction in colon segments from rats treated with trinitrobenzenesulphonic acid.

Methods: Colitis was induced in rats by intra rectal administration of trinitrobenzenesulphonic acid and followed for 5 days.

Indications of the mechanisms involved in improved sperm parameters by zinc therapy.

Objective: To determine possible indications of the mechanisms involved in improved sperm parameters by zinc therapy in asthenozoospermic men.

Subjects And Methods: Forty-five men with asthenozoospermia (>or=40% immotile sperm) were randomized into four therapy groups: zinc only: n = 11; zinc + vitamin E: n = 12 and zinc + vitamins E + C: n = 14 for 3 months, and non-therapy control group: n = 8. Semen analysis was done according to WHO guidelines.

Role of Ca2+-sensitization in attenuated carbachol-induced contraction of the colon in a rat model of colitis.

Inflammatory bowel disease is associated with reduced colonic smooth muscle contractility. However the underlying mechanism responsible for the decrease in contractility is not fully understood. In this study we investigated the role of Ca(2+)-sensitization in reduced carbachol-induced contraction of colonic segments from rats treated with trinitrobenzenesulphonic acid (TNBS).

An investigation of corneal integrity in recreational divers.

Objective: To compare the corneal integrity of recreational divers and non-divers.

Methods: The cross-sectional study was conducted at the St. Erik s Eye Hospital, Stockholm, Sweden, between September 2003 and February 2004.