Search results for "betaine"
showing 10 items of 46 documents
Endothelium- and nitric oxide-dependent vasorelaxing activities of gamma-butyrobetaine esters: possible link to the antiischemic activities of mildro…
2004
Mildronate [3-(2,2,2-trimethylhydrazine) propionate (THP)] is an antiischemic drug acting mainly via inhibition of fatty acid beta-oxidation. Some effects of the drug cannot be explained by the latter mechanism. We tested the eventual nitric oxide (NO) dependence of the mildronate action. Mildronate, gamma-butyrobetaine (GBB) and GBB methyl ester induced transient increases in nitric oxide (NO) concentrations in rat blood and myocardium. In vitro, these compounds neither modified the activities of purified neuronal and endothelial recombinant nitric oxide synthases (NOSs) nor were able to interact with their active site. GBB induced vasodilatation at high concentrations only (EC50 = 5 x 10(…
Thyroid hormone controls carnitine status through modifications of gamma-butyrobetaine hydroxylase activity and gene expression.
2002
The carnitine system plays a key role in beta-oxidation of long-chain fatty acids by permitting their transport into the mitochondrial matrix. The effects of hypothyroidism and hyperthyroidism were studied on gamma-butyrobetaine hydroxylase (BBH), the enzyme responsible for carnitine biosynthesis in the rat. In rat liver, BBH activity was decreased in the hypothyroid state and increased in hyperthyroid animals. The modifications in BBH activity correlated with changes in the enzyme Vmax values. These changes were shown to be related to hepatic BBH mRNA abundance. Thyroid hormones are known to interact with lipid metabolism, in particular by increasing long-chain fatty acid oxidation through…
Choline Metabolism and Risk of Atrial Fibrillation and Heart Failure in the PREDIMED Study
2020
Abstract Background Few studies have examined the associations of trimethylamine-N-oxide (TMAO) and its precursors (choline, betaine, dimethylglycine, and L-carnitine) with the risk of atrial fibrillation (AF) and heart failure (HF). This study sought to investigate these associations. Methods Prospective associations of these metabolites with incident AF and HF were examined among participants at high cardiovascular risk in the PREDIMED study (PREvención con DIeta MEDiterránea) after follow-up for about 10 years. Two nested case-control studies were conducted, including 509 AF incident cases matched to 618 controls and 326 HF incident cases matched to 426 controls. Plasma levels of TMAO an…
Effect of inhibiting carnitine biosynthesis on male rat sexual performance.
2008
l-carnitine has a documented role as a cofactor in cellular energy metabolism and fatty acid beta-oxidation pathways and it has also been considered to function in reproductive biology. We investigated whether decreasing concentrations of L-carnitine using an inhibitor of its biosynthesis, mildronate (3-(2,2,2-trimethylhydrazinium)-propionate), would influence the sexual behavior or sperm quality in male rats. Mildronate treatment induced a significant decrease in carnitine concentration and an increase in gamma-butyrobetaine (GBB) concentration in both plasma and testes extracts. However, the expression of carnitine palmitoyltransferase I in testes and testosterone concentration in plasma …
Enhancement of activities relative to fatty acid oxidation in the liver of rats depleted of l-carnitine by d-carnitine and a γ-butyrobetaine hydroxyl…
1995
Abstract This study was designed to examine whether the depletion of l -carnitine may induce compensatory mechanisms allowing higher fatty acid oxidative activities in liver, particularly with regard to mitochondrial carnitine palmitoyltransferase I activity and peroxisomal fatty acid oxidation. Wistar rats received d -carnitine for 2 days and 3-(2,2,2-trimethylhydrazinium)propionate (mildronate), a non-competitive inhibitor of γ-butyrobetaine hydroxylase, for 10 days. They were starved for 20 hr before being sacrificed. A dramatic reduction in carnitine concentration was observed in heart, skeletal muscles and kidneys, and to a lesser extent, in liver. Triacylglycerol content was found to …
Hopping Conductivity in Hydrogen-Bonded Antiferroelectric Compounds
1991
Antiferroelectric betaine phosphate (BP: (CH3)3NCH2COO · H3PO4) and ferroelectric betaine phosphite (BPI: (CH3)3NCH2COO · H3PO3) are molecular crystals of the amino acid betaine and the phosphoric or phosphorous acids, respectively. In both compounds the inorganic components are linked by hydrogen bonds to one-dimensional chains. The two isostructural compounds form solid solutions BPxBPI1-x at any concentration. Here we report measurements of the dielectric permittivity for concentrations 0.85 ≤ × ≤ 1 at frequencies 10−2 ≤ v ≤ 109 Hz and temperatures 2 K ≤ T ≤ 300 K. The dielectric response in BP:BPI (x = 0.95) is dominated by contributions from pure hopping conductivity which we ascribe t…
Nonthrombogenic, Biodegradable Elastomeric Polyurethanes with Variable Sulfobetaine Content
2014
For applications where degradable polymers are likely to have extended blood contact, it is often important for these materials to exhibit high levels of thromboresistance. This can be achieved with surface modification approaches, but such modifications may be transient with degradation. Alternatively, polymer design can be altered such that the bulk polymer is thromboresistant and this is maintained with degradation. Toward this end a series of biodegradable, elastic polyurethanes (PESBUUs) containing different zwitterionic sulfobetaine (SB) content were synthesized from a polycaprolactone-diol (PCL-diol):SB-diol mixture (100:0, 75:25, 50:50, 25:75 and 0:100) reacted with diisocyanatobuta…
Proton glass behavior and hopping conductivity in solid solutions of antiferroelectric betaine phosphate and ferroelectric betaine phosphite.
1991
Measurements of the dielectric permittivity are reported for solid solutions of antiferroelectric betaine phosphate and ferroelectric betaine phosphite at frequencies 10 −2 Hz T c the dielectric response is dominated by ac and dc conduction. The 40% sample exhibits pure relational behavior indicative of a transition into an orientational glass state
Urinary Arsenic Species and Methylation Efficiency During Pregnancy: Concentrations and Associated Factors in Spanish Pregnant Women
2021
Background: Arsenic (As) is considered to be toxic for humans, the main routes of exposure being through drinking water and the diet. Once ingested, inorganic arsenic can be methylated sequentially to monomethyl and dimethyl arsenicals. Several factors can affect both As exposure and methylation efficiency. Objectives: To describe the urinary concentrations of the different As species and evaluate the methylation effi-ciency during pregnancy, as well as their associated factors in a birth cohort of pregnant Spanish women. Methods: Participants in this cross-sectional study were 1017 pregnant women from two areas of Spain who had taken part in the INMA (Environment and Childhood) project (20…
Effect of salinity on Puccinellia distans (L.) Parl. treated with NaCl and foliarly applied glycinebetaine
2009
Turfgrasses general appearance is much affected by environmental stresses because the species used for this purpose are particularly exigent in terms of technical inputs and water need. In the Mediterranean area, sometimes irrigation is provided by using waste water which may contain high concentrations of dissolved salts which can cause salt stress injury and poor turf quality. Puccinellia distans (L.) Parl. is a halophyte cool season grass that seems to have a high salinity tolerance when cultivated in sodic soils or in NaCl-rich hydroponic cultures. We investigated the response of P. distans to salinity in a soil culture in a controlled growth environment. The effect of different concent…