Plasma volume with alternative tilting: effect of fluid ingestion

Hinghofer‐Szalkay, Helmut; Sauseng-Fellegger, G.; Greenleaf, J. E.

doi:10.1152/jappl.1995.78.4.1369

Cited by 13 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It remains possible, therefore, that either isotonic or hypertonic drinks could influence shifts in plasma volume. The osmolality of the drink has been found to influence shift in plasma volume during head‐up‐tilt; the decrease in plasma volume was attenuated following acute fluid loading with a hypertonic drink compared to a isotonic drink (Hinghofer‐Szalkay et al, 1995). To our knowledge, however, the influence of the osmolality of a drink on mental stress‐induced hemoconcentration has not been examined.…”

Section: Discussionmentioning

confidence: 99%

The influence of hydration status on stress‐induced hemoconcentration

et al. 2005

View full text Add to dashboard Cite

This study examined the effects of hydration status on rheological and hemodynamic activity during rest, mental stress, postural stress, and combined mental/postural stress in 24 men when euhydrated and hyperhydrated. The stress tasks elicited hemoconcentration, although the effects were less pronounced during mental stress. Hyperhydration was associated with higher plasma volume throughout. All stress tasks also perturbed hemodynamic activity, irrespective of hydration status, with the exception of heart rate reactivity, which was attenuated when hyperhydrated. As expected the combined stress during euhydration was associated with an unfavorable rheological and cardiovascular profile, which may help explain the increased incidence of cardiovascular events in the morning.

show abstract

Section: Discussionmentioning

confidence: 99%

The influence of hydration status on stress‐induced hemoconcentration

et al. 2005

View full text Add to dashboard Cite

show abstract

“…Blood density (BD) and plasma density (PD) were measured at 37.00Ϯ0.02°C with a high-precision mass densitometry device (model DMA 602 M, Paar KG) on 0.2-mL samples using the mechanical oscillator technique, 9 in which the resonant frequency of a U-shaped glass tube is determined and converted to corresponding density values. Mass density (FD) of the fluid shifted into or from the circulating blood was calculated from corresponding PD and Hct values 10 :…”

Section: Measurementsmentioning

confidence: 99%

Orthostatic Stimuli Rapidly Change Plasma Adrenomedullin in Humans

et al. 1999

View full text Add to dashboard Cite

Abstract-The aim of this study was to evaluate the effect of orthostasis on the time course of plasma adrenomedullin concentration. On 5 different days, normotensive subjects were randomized to undergo for 30 minutes either 12°, 30°, 53°, or 70°passive head-up tilt or to remain supine. Venous blood was collected from each subject in the supine position before tilting, at 3 and 27 minutes during tilting, and at 2 and 50 minutes after orthostasis. Plasma adrenomedullin increased significantly with tilt of Ն30°in a stimulus-dependent manner. Approximately half of the increase seen at 27 minutes occurred during the first 2 minutes of upright positioning; the maximum effect with 70°tilt was ϩ70%. Elevations in norepinephrine, epinephrine, aldosterone, plasma renin activity, vasopressin, heart rate, and mean arterial pressure were also significant. Hematocrit, blood density, plasma density, and plasma volume loss rose (PϽ0.05) at 53°a nd 70°tilt. Our results indicate that adrenomedullin may play an important role in stabilization of hemodynamics during passive orthostasis. In conclusion, plasma adrenomedullin rapidly increases with orthostatic challenge in a stimulus-dependent manner and also swiftly returns to baseline levels after the subject resumes the supine position. Key Words: tilt, head-up Ⅲ adrenomedullin Ⅲ barorereflex Ⅲ volume, plasma Ⅲ catecholamines T he 52-amino acid peptide adrenomedullin (ADM) is a potent vasorelaxant 1 and natriuretic 2 peptide. The strong relationship between plasma ADM and vascular tone functions in water homeostasis by increasing the glomerular filtration rate and natriuresis while lessening renal vascular resistance. 2,3 Additionally, ADM might function as an endothelium-derived relaxation factor and an autocrine or paracrine factor for vascular smooth muscle. 4 Until now, no data were available on changes in plasma ADM levels induced by orthostasis, which redistributes blood from central-to lower-body vascular beds and unloads cardiopulmonary receptors 5 ; this causes constriction of resistance and capacitance vessels, 6 in part through the action of vasopressin, angiotensin, and endothelin-1. 7,8 The present investigation was designed to test the hypothesis that plasma ADM is influenced by head-up tilting (HUT) in normotensive, euhydrated humans; to study the time course of ADM during and after HUT; and to quantify effects in relation to the intensity of orthostatic challenge. As ancillary information, hemodynamic and other endocrine as well as blood volume indicators were determined. The present study shows that ADM responds quickly and in a dose-dependent manner to HUT, and its concentration rapidly declines afterward.

show abstract

“…Plasma volume changes could be achieved by different body positions. Head-up tilt causes a redistribution of blood from the intrathoracic region to the lower part of the body followed by the filtration of plasma into the interstitial space of the lower part of the body (Hinghofer-Szalkay et al, 1995;Maw et al, 1995). These events result in central hypovolemia with a rise in neural and hormonal counterregulation caused by unloading cardiopulmonary and arterial baroreceptors (Blomqvist & Stone, 1983).…”

Section: Introductionmentioning

confidence: 99%

Body Position and the Neuroendocrine Response to Insulin-induced Hypoglycemia in Healthy Subjects

Rádiková

Penesová

Ježová

et al. 2003

Archives of Physiology and Biochemistry

View full text Add to dashboard Cite

Changes in body fluid distribution are known to influence neuroendocrine function. The aim of the present study was to test the hypothesis that changes in plasma volume affect the counterregulatory neuroendocrine response to hypoglycemia. The tests were performed in 12 subjects in two situations: 'head-up' (+60 degrees head-up tilt standing for 30 min and hypoglycemia in sitting position afterwards) and 'leg-up' (leg-up position for 30 min and hypoglycemia in leg-up position afterwards) in a random order. Insulin-induced hypoglycemia was adjusted to 2.7 mmol/l for 15 min by glucose infusion. Plasma volume was greater by 2.2% (p < 0.001) in leg-up and lower by 9.6% (p < 0.001) in head-up position compared to the basal value in sitting position. Head-up position was associated with increases in ACTH, aldosterone, norepinephrine levels and plasma renin activity (p < 0.01). Leg-up position resulted in decreases in plasma growth hormone and epinephrine concentrations (p < 0.05). Except epinephrine, the neuroendocrine response to hypoglycemia, if any, was mild. Hypoglycemia failed to activate ACTH release after head-up position. Body fluid redistribution did not modify hormonal changes during insulin hypoglycemia. In conclusion, we suggest that body position and accompanying plasma volume changes do not appear to affect neuroendocrine and counterregulatory responses to moderate, short duration hypoglycemia in healthy subjects.

show abstract

Plasma volume with alternative tilting: effect of fluid ingestion

Cited by 13 publications

References 0 publications

The influence of hydration status on stress‐induced hemoconcentration

The influence of hydration status on stress‐induced hemoconcentration

Orthostatic Stimuli Rapidly Change Plasma Adrenomedullin in Humans

Body Position and the Neuroendocrine Response to Insulin-induced Hypoglycemia in Healthy Subjects

Contact Info

Product

Resources

About