Search results for "arginine"
showing 10 items of 389 documents
Endothelium-dependent relaxation of human saphenous veins in response to vasopressin and desmopressin
1997
Purpose: The goal of this study was to determine the effects of vasopressin and the selective V 2 -receptor agonist desmopressin on human saphenous veins, with special emphasis on endothelium-mediated responses. Methods: Human saphenous vein segments were obtained from 35 patients undergoing coronary bypass surgery. Paired segments, one normal and the other deendothelized by gentle rubbing, were mounted for isometric recording of tension in organ baths. Concentration-response curves to vasopressin and desmopressin were determined in the presence and in the absence of either the V,-receptor antagonist d(CH 2 ) 5 Tyr(Me)AVP (10 −6 mol/L), the V 1 -V 2 receptor antagonist desGly-d(CH 2 ) 5 D-T…
Inhibition of nitric oxide activity by arginine analogs in human renal arteries
2001
Abstract Background: Plasma levels of endogenous guanidine compounds are increased in various pathologic conditions, including chronic renal failure. In the present study we tested the effects of some of these compounds on basal and stimulated nitric oxide activity in human renal arteries. Methods: Rings from human renal arteries were obtained from 22 patients undergoing nephrectomy. The rings were suspended in organ baths for isometric recording of tension. We then studied the effects of N G -monomethyl- l -arginine (L-NMMA), N G , N G -dimethyl- l -arginine (asymmetrical dimethylarginine [ADMA]), aminoguanidine (AG), and methylguanidine (MG) on artery rings under basal and stimulated cond…
Effects of Some Guanidino Compounds on Human Cerebral Arteries
1999
Background and Purpose —Accumulation of endogenous guanidino-substituted analogues of l -arginine in chronic renal failure might contribute to some of the vascular and neurological disorders of this pathology. We tested the hypothesis that in human cerebral arteries, some guanidino compounds may increase vascular tone, through nitric oxide (NO) synthase inhibition, and impair endothelium-dependent relaxation. Methods —Rings of human middle cerebral artery were obtained during autopsy of 26 patients who had died 3 to 12 hours before. The rings were suspended in organ baths for isometric recording of tension. We then studied the responses to N G -monomethyl- l -arginine (L-NMMA), N G , N G -…
Desmopressin in the Treatment of Nocturia: A Double-Blind, Placebo-Controlled Study
2007
Objectives: To investigate efficacy, safety, and impact on quality of sleep of desmopressin in the treatment of nocturia. Methods: Adults aged >= 18 yr with nocturia (>= 2 voids/night) received desmopressin tablets (0.1, 0.2, or 0.4 mg) during a 3-wk dose-titration period. Patients should show sufficient response during the dose-titration period (>= 20% reduction in nocturnal diuresis) and a return of nocturnal diuresis to >= 80% of baseline levels during washout. Eligible patients then entered a 3-wk double-blind treatment period and received either desmopressin or placebo. Results: 127 patients were randomised to either desmopressin (n = 61) or placebo (n = 66). Twenty (33%) desmopressin-…
Recessive multiple epiphyseal dysplasia (rMED): phenotype delineation in eighteen homozygotes for DTDST mutation R279W.
2003
Multiple epiphyseal dysplasia (MED) is a generalised skeletal dysplasia that although relatively mild is associated with significant morbidity. Joint pain, joint deformity, waddling gait, and short stature are the main clinical signs and symptoms. In the past, the disorder was subdivided into the milder Ribbing type, usually with flattened epiphyses,1 and the more severe Fairbank type with round epiphyses,2 but many cases were not classifiable as clearly either type.3 MED can be caused by mutations in at least six separate genes: COMP ,4–7 collagen IX ( COL9A1 , COL9A2 , and COL9A3 ),8–13 matrilin 3 ( MATN3 ),15 and the sulphate transporter, DTDST ( DTDST/SLC26A2 ). We have previously repor…
A female with X‐linked Nephrogenic diabetes insipidus in a family with inherited central diabetes Insipidus: Case report and review of the literature
2020
There are two forms of diabetes insipidus, central (neurohypophyseal), and nephrogenic, caused by pathogenic variants in the AVP gene and the AVPR2 or AQP2 genes, respectively. We report on a four-generation family, seven individuals had central diabetes insipidus (CDI) and the female index patient seen from age 16 to 26 years had (mild) nephrogenic diabetes insipidus. In her father with CDI, a known pathogenic heterozygous AVP variant c.232_234del p.(Glu78del) was identified, confirming the diagnosis of CDI in him and the other affected family members. In the proband, molecular analysis disclosed a novel heterozygous AVPR2 gene variant, c.962A > T p.(Asn321Ile) and an extremely skewed X-in…
Contractile effects of arginine analogues on human internal thoracic and radial arteries
2000
Abstract Objectives: Plasma levels of endogenous guanidino-substituted analogues of L -arginine are increased in various pathologic conditions. In the present study we determined the effects of some of these compounds on basal and stimulated release of nitric oxide in human internal thoracic and radial arteries. Methods: Rings of human internal thoracic and radial arteries were obtained from 16 multiorgan donors. The rings were suspended in organ baths for isometric recording of tension. Results: N G -monomethyl L -arginine (10 –6 to 10 –3 mol/L) and N G ,N G -dimethyl L -arginine (10 –6 to 10 –3 mol/L) caused concentration- and endothelium-dependent contractions. Maximal force of contracti…
Vasopressin receptors involved in adrenergic neurotransmission in the circular muscle of the human vas deferens
1998
We studied the effects of vasopressin on the adrenergic responses of in vitro preparations of circular muscle from the vas deferens obtained from 28 men undergoing elective vasectomy. Vasopressin (3 x 10(-9)-3 x 10(-8) M) enhanced the phasic contractions elicited by electrical field stimulation and noradrenaline. This potentiation was blocked by the vasopressin V1 receptor antagonist d(CH2)5Tyr(Me)vasopressin (10(-6) M) but not by the vasopressin V2 receptor antagonist [d(CH2)5, D-Ile2,Ile4,Arg8]vasopressin (10(-6) M). The Ca2+ antagonist nifedipine (10(-6) M) did not affect the potentiation of electrical field stimulation induced by vasopressin and noradrenaline but reduced KCl-induced con…
Autosomal dominant hereditary spastic paraplegia: report of a large italian family with R581X spastin mutation
2007
We describe a large kindred with a typical pure form of autosomal dominant hereditary spastic paraplegia (ADHSP). On the basis of maximum LOD score of 1.94 at theta (max)=0 with marker D2S367, we obtained suggestive evidence for linkage of ADHSP to SPG4 locus. Denaturing high-performance liquid chromatography (DHPLC) and direct sequence analysis allowed us to identify a nonsense mutation (1741* C > T) in exon 17 of the Spastin gene. This transition, carried by all the affected family members and two apparently healthy individuals, lead to truncation of the last 36 amino acids in the C-terminus of the protein. These results confirm the existence of mutation in the SPG4 gene with a reduced pe…
Continuous therapy with transdermal nitroglycerin does not affect biomarkers of vascular inflammation and injury in healthy volunteers.
2009
Continuous exposure to nitroglycerin (GTN) results in development of tolerance and is associated with increased free radical production and abnormal endothelial function. Elevated plasma biomarkers of inflammation have been shown to be associated with endothelial dysfunction in most cardiovascular conditions. It remains unclear whether exposure to GTN is also associated with increased biomarkers of endothelial and vascular injury or vascular inflammation. In an investigator-blind study, a total of 28 healthy volunteers were randomized to continuous therapy with GTN (0.6 mg/h 24 h/day for 7 days) or no therapy. Venous blood was collected on day 0 and day 7. Plasma levels of markers such as …