Search results for "Sodium"
showing 10 items of 1605 documents
Autonomic regulation of nasal vessels during changes in body position
1994
The effects of postural changes on nasal airflow and nasal capillary blood flow were investigated in 15 healthy volunteers. Measurements were performed following nasal application of saline solution (control), the alpha-1 receptor antagonist prazosin, the alpha-2 receptor antagonist yohimbine, and after application of both prazosin and yohimbine. Nasal airflow in the control experiments did not significantly differ in the upright (362 +/- 166 ml/s), dorsally recumbent (350 +/- 167 ml/s) and 70 degrees head down position (311 +/- 167 ml/s). Following application of prazosin, nasal airflow was reduced to 223 +/- 121 ml/s in the upright position. Prazosin treatment significantly reduced nasal …
Reference Values of Thyroid Hormones During the First Trimester of Pregnancy in Valencian Community (Spain) and Their Relationship with Iodine Intake
2020
Thyroid hormones require special monitoring during the first trimester of gestation. Local reference values should be applied if available, especially in iodine-deficient areas, as generalized iodine supplementation is controversial. The aim of the present study was to establish thyroid stimulating hormone (TSH) and free thyroxine (FT4) reference values in the first trimester of gestation in the Valencian community (Spain) and relate them to iodine intake. A total of 261 healthy pregnant women participated in the study. The calculated reference values were 0.128&ndash
Effect of alkalosis on plasma epinephrine responses to high intensity cycle exercise in humans
2002
The purpose of this study was to determine the effects of alkalosis on epinephrine concentrations in response to a 90 s maximal exercise test. A group of ten healthy men ingested either a bicarbonate (BS) supplement (0.3 g x kg(-1) of body mass of sodium bicarbonate) or placebo mixture (P) prior to performing a 90 s maximal cycle ergometer test. An indwelling Teflon cannula was placed in the antecubital vein and blood samples were drawn at three times at rest separated by 10 min, immediately following the protocol, and at 2.5, 5, and 10 min post exercise to determine plasma epinephrine concentrations. Sodium bicarbonate ingestion significantly ( P0.05) induced alkalosis both at rest [mean (…
PSYCHIATRIC DISTURBANCE LEADING TO POTASSIUM DEPLETION, SODIUM DEPLETION, RAISED PLASMA-RENIN CONCENTRATION, AND SECONDARY HYPERALDOSTERONISM
1968
Abstract Nine psychiatrically disturbed women were studied, variously suffering from the effects of anorexia nervosa, vomiting, and abuse of diuretics and purgatives. Each had more than one source of electrolyte depletion, and each deliberately concealed at least one of these. All were potassium-depleted, and in all but one sodium depletion was also evident. During exacerbations plasma-renin concentration was raised, secretion-rate and plasma concentration of aldosterone were increased, and the metabolic clearance of aldosterone was diminished. It is suggested that in combined sodium and potassium deficiency, conservation of sodium may be relatively more effective than that of potassium, an…
Iodine deficiency during pregnancy: a national cross-sectional survey in Latvia
2015
AbstractObjectiveLow iodine intake during pregnancy may cause thyroid dysfunction, which results in inadequate fetal brain development. In the absence of a universal salt iodization programme, we conducted a nationwide survey of iodine deficiency in pregnant women in Latvia.DesignA countrywide twenty-cluster survey, with at least twenty women per cluster. Participants completed a questionnaire on dietary habits concerning iodine intake (n 739). Thyroid function (thyroid-stimulating hormone, free thyroxine and thyroperoxidase antibodies) was measured (n 550). Urinary iodine was measured using the ammonium persulfate method (n 696).SettingThe survey was performed in all regions of Latvia duri…
Relationship between Thyroid Status during the First Trimester of Pregnancy and Neonatal Well-Being
2021
Iodine is an essential micronutrient for the synthesis of thyroid hormones. The proper functioning of the thyroid axis is essential for the normal development of the nervous system, especially in the first trimester of gestation. The aim of the present study was to analyze the perinatal outcomes, anthropometry, and APGAR test scores of newborns and to relate them to maternal thyroid status. A total of 190 newborns participated in the study. No correlation was found between thyroid stimulating hormone (TSH) and maternal ioduria values in the first trimester of gestation with the weight or length of the newborn, or the APGAR score at one minute after birth. However, we found significant diffe…
Assessment of DNA-protein crosslinks in the course of aging in two mouse strains by use of a modified alkaline filter elution applied to whole tissue…
1999
Abstract Two different mouse strains have been used for determination of age dependence of DNA-protein crosslinks by alkaline filter elution: a long lived laboratory strain, NMRI and an accelerated senescence-prone, short lived strain, SAMP1. Five organs were selected: Brain, kidney, lung, heart and liver. Remarkably in all five organs of short lived SAMP1 mice crosslinks increased significantly with age. In NMRI however only in brain and heart a significant rise in old age has been observed, while in the other organs there was no increase in DNA-protein crosslinking. Appreciable mitotic activity which is lacking in brain and heart could be the reason for this difference. Poor repair in all…
Na+ ions binding to the bradykinin B2 receptor suppress agonist-independent receptor activation.
1996
Control of the balance between receptor activation and inactivation is a prerequisite for seven transmembrane domain (7TM) receptor function. We asked for a mechanism to stabilize the inactive receptor conformation which prevents agonist-independent receptor activation. Na+ ions have reciprocal effects on agonist versus antagonist interaction with various 7TM receptors. To investigate the Na+ dependence of receptor activation we chose the bradykinin B2 receptor as a prototypic 7TM receptor. Decrease of the intracellular Na+ content from 40 mM to 10 mM of COS-1 cells transiently expressing rat B2 receptors activated the B2 receptor in the absence of agonist as shown by a 3-fold increase in t…
Effects of dantrolene on the responses to methylxanthines in the isolated guinea-pig trachea.
1991
The effect of dantrolene on the responses to methylxanthines (caffeine and theophylline) and a beta-adrenoceptor agonist (salbutamol) was studied in isolated guinea-pig trachea. Caffeine and theophylline (1 microM-10 mM) and salbutamol (1 nM-10 microM) produced concentration-dependent relaxation of spontaneous and stimulated (acetylcholine 1 mM) tone. Responses to high concentrations (10 mM) of caffeine and theophylline added to tracheal strips either unstimulated (spontaneous tone) or indomethacin (2.8 microM)-treated were reversed to contractions in the presence of dantrolene (3 microM-0.3 mM). This effect was not observed for salbutamol or when relaxant responses to the agonists were gen…
5-HT3 receptor-channels coupled with Na+ influx in human T cells: role in T cell activation.
1999
The study was conducted on a human (Jurkat) T cell line, loaded with a Na+ fluorescent probe, SBFI/AM. Serotonin and an agonist of 5-HT3 receptor-channels, 2-methyl-5HT, evoked Na+ influx, whereas the agonists of other serotonergic receptor subtypes, i.e., 5-HT1A and 5-HT1B receptors, failed to induce Na+ influx in these cells. By using 3H-BRL43694, an agonist of 5-HT3 receptor-channels, we characterized 5-HT3 lymphocyte receptors which exhibited a density (Bmax) of 300 +/- 20 fmol/10(6) cells and a Kd of 30 nM in Jurkat T cells. The T-cell 5-HT3 receptor-channel is not regulated either by the protein kinase C or by the free intracellular calcium concentrations as the agents known to activa…