Stimulation of the local renin-angiotensin system and apoptosis characterize diabetic heart. Because IGF-1 reduces angiotensin (Ang) II apoptosis, we tested whether streptozotocin-induced cardiomyopathy was attenuated in transgenic mice (TGM). Diabetes progressively depressed ventricular performance wild-type (WTM) but had no hemodynamic effect on TGM. Myocyte measured at 7 30 days after onset diabetes twofold higher WTM than necrosis apparent only more severe WTM. Diabetic nontransgenic...

Chronic fatigue syndrome (CFS) is a complex illness, which often misdiagnosed as psychiatric illness. In two previous reports, using (1)H MRSI, we found significantly higher levels of ventricular cerebrospinal fluid (CSF) lactate in patients with CFS relative to those generalized anxiety disorder and healthy volunteers (HV), but not major depressive (MDD). this third independent cross-sectional neuroimaging study, investigated pathophysiological model postulated that elevations CSF might be...

The relations between membrane cholesterol content, basal (unstimulated) transmembrane 45Ca2+ movements, cytosolic calcium levels, and fluidity were investigated in cultured rabbit aortic smooth muscle cells (SMCs) isolated SMC plasma microsomes. SMCs enriched with unesterified (free) (FC) for 18-24 hours medium containing human low density lipoprotein FC-rich phospholipid (PL) liposomes. This procedure increased mass without affecting PL mass, resulting an increase the FC/PL molar ratio...

CFS (chronic fatigue syndrome) is commonly co-morbid with POTS (postural tachycardia syndrome). Individuals CFS/POTS experience unrelenting fatigue, during orthostatic stress and ill-defined neurocognitive impairment, often described as 'mental fog'. We hypothesized that causes impairment in related to decreased CBFV (cerebral blood flow velocity). A total of 16 20 control subjects underwent graded tilt table testing (at 0, 15, 30, 45, 60 75°) continuous cardiovascular, cerebrovascular,...

Postural tachycardia syndrome (POTS), a chronic form of orthostatic intolerance, has signs and symptoms lightheadedness, loss vision, headache, fatigue, neurocognitive deficits consistent with reductions in cerebrovascular perfusion. We hypothesized that young, normocapnic POTS patients exhibit abnormal cerebral autoregulation (CA) results decreased static dynamic blood flow (CBF) autoregulation. All subjects had continuous recordings mean arterial pressure (MAP) CBF velocity (CBFV) using...

Previous investigations have allowed for stratification of patients with postural tachycardia syndrome (POTS) on the basis peripheral blood flow. One such subset, comprising "normal-flow POTS" patients, is characterized by normal resistance and volume in supine position but thoracic hypovolemia splanchnic pooling upright position. We studied 32 consecutive 14- to 22-yr-old POTS 13 low-flow POTS, 14 normal-flow 5 high-flow 12 comparably aged healthy volunteers. measured changes impedance...

The metabolism of 0.25 mM-[15N]glutamic acid in cultured astrocytes was studied with gas chromatography-mass spectrometry. Almost all 15N found as [2-15N]glutamine, [5-15N]glutamine and [15N]alanine after 210 min incubation. Some incorporation into aspartate the 6-amino position adenine nucleotides also observed, latter reflecting activity purine nucleotide cycle. After addition [15N]glutamate ammonia concentration medium declined, but intracellular ATP unchanged despite concomitant...

ABSTRACT Objectives: We determined the occurrence of fructose malabsorption in pediatric patients with previous diagnoses abdominal pain caused by a functional bowel disorder, whether restriction intake changes reporting symptoms, role dosage, and severity resultant symptoms. Patients Methods: administered breath test to children presenting persistent unexplained pain. randomly received 1, 15, or 45 g fructose, hydrogen was measured for 3 hours after ingestion. Test results were positive...

POTS (postural tachycardia syndrome) is a chronic form of OI (orthostatic intolerance). Neuropathic characterized by decreased adrenergic vasoconstriction, whereas hyperadrenergic exhibits increased vasoconstriction. We hypothesized that midodrine, an α1-adrenergic receptor agonist, would increase CVR (calf vascular resistance), decrease C(v) venous capacitance) and orthostatic in neuropathic POTS, but not alter haemodynamics POTS. A total 20 patients (12 eight hyperadrenergic), ages 12-20...

Neurocognition is impaired in chronic fatigue syndrome (CFS). We propose that the impairment relates to postural cerebral hemodynamics. Twenty-five CFS subjects and twenty control underwent incremental upright tilt at 0, 15, 30, 45, 60, 75° with continuous measurement of arterial blood pressure flow velocity (CBFV). used an n-back task n ranging from 0 4 (increased = increased difficulty) test working memory information processing. measured outcomes by number correct answers reaction time....

Syncope is a sudden transient loss of consciousness and postural tone caused by cerebral hypoperfusion. The most common form vasovagal syncope (VVS). Presyncopal progressive early hypotension in older VVS patients reduced cardiac output (CO); younger have systemic vascular resistance (SVR). Using priori criteria for CO (↓CO) SVR (↓SVR), we studied 48 recurrent young fainters comparing subgroups with VVS-↓CO, VVS-↓SVR, both VVS-↓CO&↓SVR.Subjects were supine during 70-degrere upright tilt...

Postural tachycardia syndrome (POTS) is a heterogeneous condition. We stratified patients previously evaluated for POTS on the basis of supine resting cardiac output (CO) or with complaint platypnea "shortness breath" during orthostasis. hypothesize that postural hyperventilation one cause and hyperventilation-associated occurs when initial reduction in CO sufficiently large. also propose circulatory abnormalities normalize restoration

The present study investigated the effects of sustained hydrostatic pressure (SHP; up to 4 cm H2O) on human umbilical vein endothelial cell (HUVEC) proliferation, focal adhesion plaque (FAP) organization, and integrin expression. Exposure HUVECs SHP stimulated proliferation a selective increase in expression subunit alphaV. alphaV was observed as early hours after exposure preceded detectable increases bromodeoxyuridine labeling index. Laser confocal microscopy studies demonstrated...

Standing translocates thoracic blood volume into the dependent body. The skeletal muscle pump participates in preventing orthostatic intolerance by enhancing venous return. We investigated hypothesis that function is impaired postural tachycardia (POTS) associated with low calf flow (low-flow POTS) and depends general on flow. compared 12 subjects have low-flow POTS 10 controls 7 patients normal using strain-gauge plethysmography to measure peripheral flow, capacitance, function. Blood was...

Background— One variant of postural tachycardia syndrome (POTS), designated low-flow POTS, is associated with decreased peripheral blood flow related to impaired local vascular regulation. Methods and Results— To investigate the hypothesis that microvascular endothelial dysfunction produces in we performed experiments using laser-Doppler flowmetry (LDF) combined iontophoresis 15 POTS patients, 17 normal-flow 13 healthy reference volunteers varying age from 14 22 years. We tested whether...

POTS (postural tachycardia syndrome) is associated with low blood volume and reduced renin aldosterone; however, the role of Ang (angiotensin) II has not been investigated. Previous studies have suggested that a subset patients increased vasoconstriction related to decreased bioavailable NO (nitric oxide) volume. reduces integral renin–Ang system. Thus, in present study, we investigated relationship between volume, II, renin, aldosterone peripheral flow patients. was diagnosed by 70° upright...

ABSTRACT Acetylcholine‐induced endothelium‐dependent vasodilation in conduit arteries primarily depends on nitric oxide (NO). However, the biochemical mediators microvasculature remain less well defined. We tested whether prostaglandins and NO are responsible for cutaneous acetylcholine‐mediated if they interact to modulate vasodilation. measured skin blood flow (SBF) using laser Doppler (LDF) with intradermal microdialysis calves of 23 healthy volunteers. examined response SBF different...

Low flow postural tachycardia syndrome (POTS), is associated with reduced nitric oxide (NO) activity assumed to be of endothelial origin. We tested the hypothesis that cutaneous microvascular neuronal NO (nNO) impaired, rather than (eNO), in POTS. performed three sets experiments on subjects aged 22.5 +/- 2 yr. used laser-Doppler flowmetry response sequentially increase acetylcholine (ACh) doses and local heating calf as bioassays for NO. During we showed when selective nNO synthase (nNOS)...

We tested the hypothesis that cyclooxygenases (COXs) or COX products inhibit nitric oxide (NO) synthesis and thereby mask potential effects of NO on reactive hyperemia in cutaneous circulation. performed laser-Doppler flowmetry (LDF) with intradermal microdialysis 12 healthy volunteers aged 19-25 yr. LDF was expressed as percent vascular conduction (%CVC) maximum %CVC (%CVC(max)) where CVC is LDF/mean arterial pressure. nonisoform-specific synthase inhibitor nitro-L-arginine (NLA, 10 mM),...

Local cutaneous heating produces vasodilation that is largely nitric oxide (NO) dependent. We showed angiotensin II (ANG II) attenuates this by an ANG receptor, type 1 (AT1R)-dependent mechanism reversible with the antioxidant ascorbate, indicating oxidative stress. Reactive oxygen species (ROS) produced employ NADPH and xanthine oxidase pathways. To determine whether these mechanisms pertain to skin, we measured local 10 μM II, using apocynin inhibit allopurinol oxidase. also inhibited...