Search results for "OTR"
showing 10 items of 6791 documents
Dopamine induces inhibitory effects on the circular muscle contractility of mouse distal colon via D1- and D2-like receptors
2016
Dopamine (DA) acts as gut motility modulator, via D1- and D2-like receptors, but its effective role is far from being clear. Since alterations of the dopaminergic system could lead to gastrointestinal dysfunctions, a characterization of the enteric dopaminergic system is mandatory. In this study, we investigated the role of DA and D1- and D2-like receptors in the contractility of the circular muscle of mouse distal colon by organ-bath technique. DA caused relaxation in carbachol-precontracted circular muscle strips, sensitive to domperidone, D2-like receptor antagonist, and mimicked by bromocriptine, D2-like receptor agonist. 7-Chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benz…
Increased Body Weight and Fat Mass After Subchronic GIP Receptor Antagonist, but Not GLP-2 Receptor Antagonist, Administration in Rats
2019
Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-2 (GLP-2) are hormones secreted from the enteroendocrine cells after a meal. They exert their actions through activation of G protein-coupled receptors (R), the GIPR and GLP-2R, respectively. Both have been reported to influence metabolism. The purpose of the study was to investigate the role of the hormones in the regulation of lipid and bone homeostasis by subchronic treatment with novel GIPR and GLP-2R antagonists. Rats were injected once daily with vehicle, GIPR, or GLP-2R antagonists for 3 weeks. Body weight, food intake, body composition, plasma lipoprotein lipase (LPL), adipokines, triglycerides and the mark…
Vascular biotransformation of organic nitrates is independent of cytochrome P450 monooxygenases
2020
Background and Purpose Organic nitrates such as nitroglycerin (NTG) or pentaerythritol tetranitrate (PETN) have been used for over a century in the treatment of angina or ischaemic heart disease. These compounds are prodrugs which release their nitrovasodilators upon enzymic bioactivation by aldehyde dehydrogenase (ALDH2) or cytochromes P450 (CYP). Whereas ALDH2 is known to directly activate organic nitrates in vessels, the contribution of vascular CYPs is unknown and was studied here. Experimental Approach As all CYPs depend on cytochrome P450 reductase (POR) as electron donor, we generated a smooth muscle cell-specific, inducible knockout mouse of POR (smcPOR−/−) to investigate the contri…
Tocotrienol Affects Oxidative Stress, Cholesterol Homeostasis and the Amyloidogenic Pathway in Neuroblastoma Cells: Consequences for Alzheimer’s Dise…
2016
One of the characteristics of Alzheimer´s disease (AD) is an increased amyloid load and an enhanced level of reactive oxidative species (ROS). Vitamin E has known beneficial neuroprotective effects, and previously, some studies suggested that vitamin E is associated with a reduced risk of AD due to its antioxidative properties. However, epidemiological studies and nutritional approaches of vitamin E treatment are controversial. Here, we investigate the effect of α-tocotrienol, which belongs to the group of vitamin E, on AD-relevant processes in neuronal cell lines. In line with the literature, α-tocotrienol reduced the ROS level in SH-SY5Y cells. In the presence of tocotrienols, cholesterol…
Role of Regular Physical Activity in Neuroprotection against Acute Ischemia
2020
One of the major obstacles that prevents an effective therapeutic intervention against ischemic stroke is the lack of neuroprotective agents able to reduce neuronal damage; this results in frequent evolution towards a long-term disability with limited alternatives available to aid in recovery. Nevertheless, various treatment options have shown clinical efficacy. Neurotrophins such as brain-derived neurotrophic factor (BDNF), widely produced throughout the brain, but also in distant tissues such as the muscle, have demonstrated regenerative properties with the potential to restore damaged neural tissue. Neurotrophins play a significant role in both protection and recovery of function followi…
Biological activities of polyphenols-enriched propolis from Argentina arid regions
2015
Background: Propolis is a bioactive natural product collected by honeybees (Apis mellifera) fromplant sources. Purpose: This studywas undertaken to determine the effect of propolis extracts from arid region of Argentina, on the activity/expression of pro-inflammatory enzymes, and as potential free radical scavenger, antifungal and anthelmintic agent as well as to get a first insight into the polyphenolic profile of the active fractions.Study design/methods: Two propolis samples were collected in different time from hives located in Tucumán, Argentina. They are representative of the collection time of the raw material for phytotherapeutical purposes. Ethanolic extracts from both propolis wer…
Hepatoprotective effects of extracts, fractions and compounds from the stem bark of Pentaclethra macrophylla Benth: Evidence from in vitro and in viv…
2021
Abstract Aim To identify the bioactive hepatoprotective components of the ethanol extract of Pentaclethra macrophylla stem bark using in vitro and in vivo approaches. Methods The bioguided-fractionation of the ethanol extract was based on the substances’ capacity to prevent in vitro, the lipid peroxidation of hepatocytes’ membranes induced by hydrogen peroxide. For the in vivo hepatoprotective test, mice were treated orally with the ethyl acetate (EtOAc) fraction of the ethanol extract at doses of 50 and 75 mg/kg/day for one week and subjected to d -galactosamine/lipopolysaccharide (GaIN/LPS)-induced hepatotoxicity. Blood samples were collected for alanine aminotransferase (ALAT), aspartate…
Antioxidant capacity of phenolic compounds on human cell lines as affected by grape-tyrosinase and Botrytis-laccase oxidation.
2017
Phenolic components (PCs) are well-known for their positive impact on human health. In addition to their action as radical scavengers, they act as activators for the intrinsic cellular antioxidant system. Polyphenol oxidases (PPOs) such as tyrosinase and laccase catalyze the enzymatic oxidation of PCs and thus, can alter their scavenging and antioxidative capacity. In this study, oxidation by tryosinase was shown to increase the antioxidant capacity of many PCs, especially those that lack adjacent aromatic hydroxyl groups. In contrast, oxidation by laccase tended to decrease the antioxidant capacity of red wine and distinct PCs. This was clearly demonstrated for p-coumaric acid and resverat…
Identification of theprothoracicotropic hormone(Ptth) coding gene and localization of its site of expression in the pea aphidAcyrthosiphon pisum
2017
Insect hormones control essential aspects of physiology, behaviour and development in insects. The majority of insect hormones are peptide hormones that perform a highly diverse catalogue of functions. Prothoracicotropic hormone (PTTH) is a brain neuropeptide hormone whose main function is to stimulate the secretion of ecdysone (the moulting hormone) by the prothoracic glands in insect larvae thus playing a key role in the control of moulting and metamorphosis. Moreover, both PTTH release or blockade have been reported to act as a switch to terminate or initiate larval and pupal diapauses. In insects, diapause is a prevalent response often regulated by the photoperiod. It has been shown tha…
Apolipoprotein B is regulated by gonadotropins and constitutes a predictive biomarker of IVF outcomes
2016
Background Follicular fluid (FF) is an important micro-environment influencing oocyte growth, its development competence, and embryo viability. The FF content analysis allows to identify new relevant biomarkers, which could be predictive of in vitro fertilization (IVF) outcomes. Inside ovarian follicle, the amount of FF components from granulosa cells (GC) secretion, could be regulated by gonadotropins, which play a major role in follicle development. Methods This prospective study included 61 female undergoing IVF or Intra-cytoplasmic sperm injection (ICSI) procedure. Apolipoprotein B (APOB) concentrations in follicular fluid and APOB gene and protein expression in granulosa cells from rep…