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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Utilizing a highly sensitive radioimmunoassay (RIA) for 1-desamino-8-D-arginine vasopressin (DDAVP) and a constant infusion kinetic protocol we measured DDAVP clearance rates (CR) in 6 non-pregnant ewes. Despite mean (and SEM) plasma DDAVP levels as high as 5349 (+/- 151) pg/ml, no changes in blood pressure or heart rate were observed. The CR of DDAVP was 3.6 (+/- 0.2) ml/kg X min. This CR is only 23% of the mean arginine vasopressin (AVP) CR measured in similar animals in an earlier study. The relatively decreased CR of DDAVP appears to account largely for the approximately 5-fold prolongation of antidiuresis of this synthetic derivative relative to AVP.
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PMID:DDAVP (1-desamino-8-D-arginine vasopressin) clearance rate. 649 88

Immunocytochemical studies have demonstrated that nerve fibres containing immunoreactive vasopressin project to many areas of the central nervous system. In the present investigation, the presence of immunoreactive arginine vasopressin (IR-AVP) in the hippocampus of Wistar rats was confirmed by radioimmunoassay. The vasopressin content of the dorsal hippocampus was 30.3 +/- 7.3 pg IR-AVP/mg soluble protein (mean +/- SEM, n = 9) and that of the ventral hippocampus was 81.4 +/- 8.3 pg IR-AVP/mg soluble protein (n = 9), while tissue from the cerebral cortex contained no detectable vasopressin. That the immunoreactivity was due to vasopressin was confirmed by its absence in hippocampal or cortical tissue from homozygous Brattleboro rats, which are genetically unable to synthesize vasopressin.
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PMID:Neurohypophysial peptides and the hippocampus. I. Vasopressin immunoreactivity in the rat hippocampus. 666 24

A sensitive and specific RIA system for measurement of urinary arginine vasopressin (AVP) was developed. RIA sensitivity was 0.4 microU/l (approximately 0.8 pg/ml). Urine samples were extracted using columns of octadecasilyl-silica. The mean (+/- SEM) recovery of P after extraction (77.7 +/- 1.4%) was independent of urinary osmolality. The extracted immunologically active material migrated similarly to synthetic AVP on high pressure liquid chromatography. AVP immunoreactivity was found to be stable in urine stored for 24 h at room temperature and stable for 3 months when acidified promptly and stored at -20 C. Using the RIA system, we measured urinary AVP excretion as a percentage of total body AVP clearance. For this study, AVP (3.7 microU/min . kg) was infused in into four healthy nonsmoking adults in whom endogenous AVP was suppressed by oral water loading. The mean urinary AVP excretion rate was 14.7 +/- 2.1%. There was a highly significant positive correlation between log urinary AVP concentration and urinary osmolality (r = 0.97).
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PMID:Radioimmunoassay of arginine vasopressin in urine: development and application. 688 66

Levels of arginine vasopressin have been measured in the blood and cerebrospinal fluid of patients with benign intracranial hypertension and raised intracranial pressure, patients with other neurological diseases and in normal control subjects. There was no difference in blood levels in each of the 3 groups (mean +/- SEM, 2.8 +/- 0.5, 2.5 +/- 0.25, 2.53 +/- 0.4 pg/ml). However, levels of arginine vasopressin in the cerebrospinal fluid in patients with benign intracranial hypertension and other neurological diseases were higher (mean +/- SEM, 0.64 +/- 0.005, 0.61 +/- 0.04 pg/ml), than in the control group (0.49 +/- 0.06), but not different from each other. The origin of arginine vasopressin in cerebrospinal fluid is uncertain and a number of possibilities are discussed.
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PMID:Arginine vasopressin levels in cerebrospinal fluid in neurological disease. 709 2

The cardiovascular response and the changes of plasma arginine vasopressin (AVP) concentration following graded doses of AVP infused intravenously have been defined in six normal young men. The same measurements were also made during fluid deprivation in a patient with both nephrogenic diabetes insipidus and systemic hypertension. When, following AVP infusion, mean diastolic arterial pressure increased from 72 +/- 3 mmHg (SEM) to 78 +/- 2 mmHg (SEM) in the normal subject group, mean plasma AVP increased by 14.5 fmol/ml. When the patient was deprived of water, diastolic pressure increased, despite the fluid loss, from 90 to 105 mmHg, with a comparable increase of plasma AVP concentration of 15.3 fmol/ml. Further increases of plasma AVP concentration in either the normal subjects or in the patient were not associated with further increments of arterial pressure. We suggest that under pathophysiological circumstances in man plasma AVP concentrations may achieve levels which have a significant cardiovascular effect.
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PMID:The cardiovascular effect of vasopressin in relation to its plasma concentration in man and its relevance to high blood pressure. 721 20

To assess the ability of the liver to remove immunoreactive arginine vasopressin (AVP) from the circulation and to determine the effect of certain metabolic factors on the process, a study was carried out with rat livers perfused at 37 C with an oxygenated albumin--electrolyte solution containing AVP (117 +/- 4.5 muU/ml). In controls, the hepatic clearance of AVP was 795 +/- 120 microliter/min (SEM). The addition of AVP in concentrations up to 9029 microU/ml, perfusion with a glucose-free medium, or perfusion without oxygen did not significantly alter the hepatic clearance of AVP. However, perfusion with cold medium (11 C) significantly altered AVP removal in that initially AVP removal increased, while later on AVP removal became completely inhibited. This phenomenon may possibly be a consequence of a cold-induced increase in hepatic AVP trapping which is rapidly saturated due to a cold-induced depression of AVP transport and degradation. Support for this thesis was provided by finding that high AVP concentrations depressed the cold-endhancing removal phase.
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PMID:Removal of immunoreactive arginine vasopressin by the perfused rat liver. 735 52

The effect of nursing on plasma levels of oxytocin (OT), arginine vasopressin (AVP), and PRL was studied in six normal women 2-3 days post partum. Maternal blood samples were obtained for measurement of OT, AVP, PRL, sodium, and osmolality 3 and 0 min before suckling, at 3-min intervals for 15 min during suckling, and 5 min after completion of suckling. Plasma OT rose during suckling from a mean (+/- SEM) baseline value of 1.1 +/- 0.2 to 3.6 +/- 0.6 microU/ml by 3 min (P < 0.001), reached a peak level of 6.4 +/- 1.5 microU/ml by 6 min (P < 0.005), and remained elevated for the entire 15-min period of suckling. Serial measurements of plasma OT during suckling failed to show a pattern consistent with episodic secretion. The baseline plasma AVP concentration was 0.4 +/- 0.1 microU/ml and was not significantly altered by suckling. Plasma sodium and osmolality remained unchanged during the suckling period. The baseline serum PRL level was 268 +/- 24 ng/ml and rose to 362 +/- 31 ng/ml after 15 min of suckling (P < 0.05). The data suggest that suckling is a specific stimulus for OT and PRL secretion but has no effect on AVP release.
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PMID:The effect of nursing on neurohypophyseal hormone and prolactin secretion in human subjects. 741 69

Over a 54-hour period, blood was removed from 8 adult sheep (body weight, 38.1 +/- 0.5 kg, mean +/- SEM) in 9 episodes, 5 on day 1, 3 on day 2, and 1 on day 3. Cumulative blood loss was 1,630 +/- 63, 2,380 +/- 71, and 2,693 +/- 69 ml on days 1, 2, and 3, respectively. Blood samples (20 ml) were collected from 5 control ewes (33.8 +/- 2.8 kg) at equivalent times. Over the first day, mean arterial blood pressure decreased in the hemorrhaged sheep from 101 +/- 2 mm of Hg to 76 +/- 5 mm of Hg, but returned to control values by the beginning of the second day and, thereafter, was not different from control values. Heart rate was increased after the first hemorrhage episode and remained high throughout the entire protocol. Over the entire period, there were statistically significant decreases in hematocrit, plasma osmolality, sodium, total calcium (P < 0.001), potassium, and chloride values (P < 0.05). There was no change in plasma phosphate, bicarbonate, creatinine, or magnesium concentrations and an increase in plasma urea nitrogen (P < 0.001) concentrations. Plasma arginine vasopressin concentration was increased significantly (P < 0.001) over the entire period. Plasma ACTH concentration was significantly (P < 0.05) increased over time, but only some values on day 1 were significantly outside the normal range of the control group data. Because of wide variation between sheep, the group data for aldosterone were not significantly different from control values.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cardiovascular, hormonal, and metabolic responses to severe prolonged hemorrhage in adult sheep. 748 5

The possible regulation of adenosine 3',5'-cyclic monophosphate (cAMP) accumulation by arachidonic acid (AA) was studied in segments, microdissected from the rat kidney, which are sensitive to arginine vasopressin (AVP). In the presence of 5 microM indomethacin, the addition of 5 microM AA did not impair AVP-dependent cAMP accumulation (measured during 4 min at 35 degrees C) in the cortical or outer medullary collecting tubule, but decreased this response in the thick ascending limb with an inhibition much more pronounced in the medullary portion (MTAL) than in the cortical portion. In MTAL, the response to 10 nM AVP was inhibited by 34.4 +/- 9.6% (SEM) and 65.8 +/- 5.4% with 1 microM and 5 microM AA, respectively, N = 5 experiments. AVP-, glucagon- and calcitonin-sensitive cAMP levels in MTAL were inhibited by 5 microM AA to a similar extent. AA-induced inhibition was unaffected by the presence of inhibitors of AA metabolism: (1) either 10 microM indomethacin or 50 microM ibuprofen added to all media; (2) a 10-min pre-incubation and a 4-min incubation of MTAL samples with 10 microM eicosa-5,8,11,14-tetrayonic acid, (3) a 1-h preincubation with either 30 microM SKF-525A, 20 microM ketoconazole, or 20 microM nordihydroguariaretic acid. In contrast to AA, 11 other saturated or unsaturated fatty acids had no inhibitory effect on the AVP-dependent cAMP level. In fura-2-loaded MTAL samples, AA induced a slow increase of the intracellular calcium concentration ([Ca2+]i) which reached 21.0 +/- 3.8 nM and 92.9 +/- 21.4 nM over basal values (n = 11) at 2 min and 4 min, respectively, after the beginning of the superfusion of 5 microM AA. AA-induced inhibition of AVP-dependent cAMP accumulation was due neither to the increase in [Ca2+]i elicited by AA, nor to an activation of protein kinase C because this inhibition: (1) was not blocked when MTAL samples were incubated either in zero Ca2+ medium, or in the presence of 1,2-bis(2-aminophenoxy)ethane-N, N, N', N'-tetraacetic acid (BAPTA) to chelate [Ca2+]i, and (2) it was not reproduced by a pre-treatment of MTAL segments with a phorbol ester. Pre-incubation of MTAL (6 h at 35 degrees C) with 500 ng/ml pertussis toxin (PTX) prevented AA-induced inhibition: in the presence of PTX inhibition was 24.7 +/- 6.6% vs 10 nM AVP, as compared to 81.6 +/- 4.0% in control groups, i.e in the absence of PTX, N = 6.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Arachidonic acid inhibits hormone-stimulated cAMP accumulation in the medullary thick ascending limb of the rat kidney by a mechanism sensitive to pertussis toxin. 779 41

The immediate and longer term variability of selected vasoactive- and volume-regulating neurohormones were measured in patients entering a substudy of the Studies of Left Ventricular Dysfunction--a randomized clinical trial in patients with left ventricular ejection fraction < or = 35%. The variability of these hormones has not been determined in a large cohort of patients. Immediate (short-term) variability was assessed by systematically comparing levels after 15 and 30 minutes of supine rest at the initial visit, and longer term variability was assessed by comparing 30-minute supine rest values at the initial visit with corresponding values taken at 30 minutes after 16 to 24 days of stable therapy. Initial values obtained at the first visit after 30-minute supine rest for all 209 patients were (mean +/- SEM) 512 +/- 21 pg/ml pg/ml for plasma norepinephrine, 1.9 +/- 0.2 ng/ml/hr for plasma renin activity, 3.0 +/- 0.1 pg/ml for plasma arginine vasopressin, and 129 +/- 5.3 pg/ml for plasma atrial natriuretic peptide. All variables were moderately increased relative to established normal values. There was a small but significant decrease from 15- to 30-minute supine posture in all neurohormones, except arginine vasopressin. In the presence of stable background therapy, no significant differences were found between measurements obtained after 30 minutes supine rest at the initial visit and 16 to 24 days later. Spearman correlation coefficients corresponding to immediate and longer term variability were high (range 0.55 to 0.79) (p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Neurohumoral variability in left ventricular dysfunction. SOLVD Investigators. Studies of Left Ventricular Dysfunction. 785 27


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