A new extraction of arginine vasopressin from blood: The use of octadecasilyl-silica

Larochelle, F. T.; North, William G.; Stern, Paul C.

doi:10.1007/bf00580849

Cited by 154 publications

(43 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the analysis of plasma AVP, the samples were collected into an ice-chilled glass tube containing 10 IU of heparin and 500 IU of aprotinin per milliliter of blood. Samples were extracted by a modification of the procedure of La Rochelle et al (19), and AVP levels were determined by radioimmunoassay (37). Plasma AVP recoveries in our laboratory averaged 70%.…”

Section: Methodsmentioning

confidence: 93%

Neuronal NO modulates spontaneous and ANG II-stimulated fetal swallowing behavior in the near-term ovine fetus

El-Haddad

Chao

et al. 2002

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

. Neuronal NO modulates spontaneous and ANG II-stimulated fetal swallowing behavior in the near-term ovine fetus. Am J Physiol Regulatory Integrative Comp Physiol 282: R1521-R1527, 2002; 10.1152/ajpregu. 00229.2001.-Spontaneous fetal swallowing occurs at a markedly higher rate compared with spontaneous adult drinking activity. This high rate of fetal swallowing is critical for amniotic fluid volume regulation. Central NO is critical for maintaining the normal rate of fetal swallowing, as nonselective inhibition of NO (with central N G -nitro-L-arginine methyl ester) suppresses spontaneous and angiotensin II (ANG II)-stimulated swallowing. We sought to differentiate the contributions of central endothelial vs. neuronal NO in the regulation of spontaneous and stimulated fetal swallowing, using a selective neuronal NO synthase (nNOS) inhibitor. Six time-dated pregnant ewes and fetuses were chronically prepared with fetal vascular and intracerebroventricular (icv) catheters and electrocorticogram (ECoG) and esophageal electromyogram electrodes and studied at 130 Ϯ 1 days of gestation. After an initial 2-h baseline period (0-2 h), the selective nNOS inhibitor Npropyl-L-arginine (NPLA) was injected icv (2-4 h). At 4 h, the dose of NPLA was repeated, together with ANG II, and fetal swallowing was monitored for a final 2 h. Four fetuses also received an identical control study (on an alternate day) in which NPLA was replaced with artificial cerebrospinal fluid (aCSF). Suppression of nNOS by icv NPLA significantly reduced mean (Ϯ SE) spontaneous fetal swallowing (1.35 Ϯ 0.12 to 0.50 Ϯ 0.07 swallows/min; P Ͻ 0.001). Injection of ANG II in the presence of NPLA had no dipsogenic effect on fetal swallowing (0.68 Ϯ 0.09 swallows/min). In the aCSF study, icv aCSF did not change fetal swallowing (0.93 Ϯ 0.10 vs. 0.95 Ϯ 0.09 swallows/min), whereas icv ANG II resulted in a significant increase in the rate of fetal swallowing (2.0 Ϯ 0.04 swallows/ min; P ϭ 0.001). We speculate that the suppressive dipsogenic effects of central NPLA indicate that spontaneous and ANG IIstimulated fetal swallowing is dependent on central nNOS activity. amniotic fluid; angiotensin II THIRST AND APPETITE-MEDIATED ingestive behavior develop and are likely imprinted in utero, thus preparing for newborn and adult ingestive behavior. Fetal swallowing activity is markedly different from that of the adult, as basal fetal swallowing occurs at a markedly (6-fold) higher rate compared with basal adult drinking activity after body weight differences are adjusted for (35). This high rate of basal fetal swallowing is critical for the regulation of amniotic fluid volume (30) and the development of the fetal gastrointestinal tract. Disordered fetal swallowing has been associated with both a decrease (oligohydramnios) and an increase (polyhydramnios) in amniotic fluid volume (11, 18). Both conditions are associated with a significant increase in perinatal morbidity and mortality, and limited treatment modalities are currently available. However, the mechanisms under...

show abstract

Section: Methodsmentioning

confidence: 93%

Neuronal NO modulates spontaneous and ANG II-stimulated fetal swallowing behavior in the near-term ovine fetus

El-Haddad

Chao

et al. 2002

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

show abstract

“…Plasma cortisol and aldosterone concentrations were measured by direct radioimmunoassays using commercially available kits (Diagnostic Products Corp., Los Angeles, CA, USA). Plasma arginine vasopressin concentration was measured by radioimmunoassay after extraction on octadecasilyl-silica columns (Sep-Pak C 18; Waters, Milford, MA, USA) according to LA ROCHELLE et al [11]. Serum meta-and normetanephrine determinations were performed by high performance liquid chromatography followed by electrochemical detection [12].…”

Section: Plasma Hormonesmentioning

confidence: 99%

Haemodynamic and endocrinological effects of noninvasive mechanical ventilation in respiratory failure

Thorens

Ritz²,

Reynard³

et al. 1997

Eur Respir J

View full text Add to dashboard Cite

The aim of this study was to investigate the haemodynamic and endocrinological effects of noninvasive positive pressure ventilation (NIPPV).Eleven patients with oedema and recent hypercapnic and hypoxaemic worsening of a chronic respiratory insufficiency were included. Echocardiography, cardiac radionuclide assessment, blood catecholamines, salt and water handling hormones were measured at admission and discharge (long study (LS)). To discriminate between the action of NIPPV and other treatments, measurements were performed on the fourth day, for 4 h without NIPPV and 4 h with NIPPV (short study (SS)).NIPPV entailed a correction of Pa,CO 2 and an increase of Pa,O 2 in LS and SS. Oedema disappeared. Body weight decreased (from 85±42 to 81±40 kg) during LS. Systolic and mean pulmonary arterial pressure decreased in LS and SS. Right ventricular ejection fraction increased in LS. Left ventricular ejection fraction did not change. Cardiac index was normal on admission and then decreased. Natriuretic peptides and catecholamines were increased on admission, whereas plasma renin activity, aldosterone and vasopressin were normal.We suggest that in these patients, oedema can occur independently of reninangiotensin-aldosterone-vasopressin and with a normal cardiac output. Noninvasive positive pressure ventilation allowed a correction of blood gases, associated with the resolution of oedema, a decrease in pulmonary arterial pressures and an increase in right ventricular ejection fraction. Eur Respir J 1997; 10: 2553-2559 Severe chronic respiratory insufficiency often leads to pulmonary arterial hypertension and cor pulmonale, which are associated with increased mortality [1]. Peripheral oedema is often witnessed in these patients, and the traditional view has been to assume that this results from right ventricular failure and/or the increased secretion of salt and water-handling hormone [2,3]. Longterm noninvasive positive pressure ventilation (NIPPV) is effective in improving blood gases and thereby decreasing pulmonary hypertension, clearing oedema, and reducing morbidity and mortality associated with this condition [4]. Its beneficial effects on oedema could result from improved right ventricular function and cardiac output as well as a lowering of salt and water-handling hormone levels, as demonstrated during invasive mechanical ventilation [5]. However, there is a scarcity of published data on the consequences of NIPPV on pulmonary haemodynamics, ventricular function and hormonal patterns in oedematous patients with chronic respiratory insufficiency in which long-term ventilatory support is initiated.The aims of this study were, therefore: 1) to measure the haemodynamic effects of NIPPV, which would be expected to reduce pulmonary arterial pressure and improve right ventricular ejection fraction because of the correction of Pa,CO 2 and Pa,O 2 ; 2) to explore the haemodynamic and endocrine profiles of patients during a recent worsening of chronic hypercapnic respiratory insufficiency, in particular the major h...

show abstract

“…AVP extraction was based on a method using small columns packed with octadecasilyl silica (C18 Sep-Paks, Waters Assoc., Milford, MA, USA) as described previously (La Rochelle et al, 1980;Glanzer et al, 1984;Galard et al, 1985). Extraction recovery was determined by the addition of various concentrations of AVP to a plasma pool from a dog which had received a water load.…”

Section: A Vp Extraction and Radioimmunoassaymentioning

confidence: 99%

Effect of methadone on plasma arginine vasopressin level and urine production in conscious dogs

Hellebrekers

Mol

Brom

et al. 1987

European Journal of Pharmacology

View full text Add to dashboard Cite

The aim of this study was to examine the effect of i.v. methadone on the plasma arginine-vasopressin (AVP) levels and urine production in 9 conscious dogs. A highly significant increase from the baseline plasma AVP values of below 3 pg/ml occurred within 5 min following methadone administration. Maximum levels were reached within 30-50 min post-injection and varied from 18.5 to 100 pg/ml. A significant decrease in urine production was not seen under these experimental conditions. Mean arterial blood pressure did not change significantly during the experiment. Apart from the partial influence of the methadone-induced respiratory acidosis, we postulate a direct relationship between i.v. administration of methadone and the increased plasma AVP levels in dogs.Methadone; Arginine-vasopressin; (Dog)

show abstract

A new extraction of arginine vasopressin from blood: The use of octadecasilyl-silica

Cited by 154 publications

References 13 publications

Neuronal NO modulates spontaneous and ANG II-stimulated fetal swallowing behavior in the near-term ovine fetus

Neuronal NO modulates spontaneous and ANG II-stimulated fetal swallowing behavior in the near-term ovine fetus

Haemodynamic and endocrinological effects of noninvasive mechanical ventilation in respiratory failure

Effect of methadone on plasma arginine vasopressin level and urine production in conscious dogs

Contact Info

Product

Resources

About