Cardiovascular, renal, and endocrine responses in male quadriplegics during head-out water immersion

1990 ◽  
Vol 258 (6) ◽  
pp. R1424-R1430 ◽  
Author(s):  
F. Tajima ◽  
S. Sagawa ◽  
J. Iwamoto ◽  
K. Miki ◽  
B. J. Freund ◽  
...  

The present study was undertaken to determine the relative influence of the action of the central nervous system on the mechanism of water-immersion-induced diuresis by comparing physiological responses of quadriplegic (QP) and normal subjects. After overnight fasting seven male QP subjects with complete cervical cord transections (C5-C8) and six normal men were tested before, during, and after 3 h of head-out immersion (HOI) in thermoneutral water (34.5-35.0 degrees C). The reversible increase in urine flow and the total urine volume (309 +/- 53 ml in 3 h) in QP subjects were comparable with that of the normal subjects (318 +/- 96 ml in 3 h). While osmolal excretion was increased in QP subjects, its magnitude was less when compared with that of normal subjects. Instead, the increased urine flow in QP subjects was characterized by increased glomerular filtration rate (GFR) and free water clearance, in contrast to a predominantly osmotic diuresis with no changes in GFR in the normal subjects. The HOI elevated (P less than 0.05) systolic pressure only in QP subjects, whereas the increase in cardiac output was the same in both groups. While plasma renin activity and aldosterone responses to HOI in QP subjects were comparable with those of normal individuals, plasma atrial natriuretic factor (ANF) in QP subjects was twofold higher (P less than 0.05) during HOI, and the approximately threefold increase in ANF (P less than 0.05) in QP subjects due to HOI was the same as that of normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

1978 ◽  
Vol 45 (5) ◽  
pp. 786-790 ◽  
Author(s):  
I. H. Zucker ◽  
J. P. Gilmore

The present investigation evaluated the renal and hemodynamic responses to head-out water immersion in dogs. Dogs were immersed in the vertical (seated) position in a 34 degrees C bath. Urine flow (V), osmolar clearance (Cosm), free water clearance (CH2O), sodium excretion (UNa+V), potassium excretion (UK+V), GFR, effective renal plasma flow (ERPF), central venous pressure (CVP), and cardiac output (CO) all increased significantly during immersion. This response was unchanged by bilateral cervical vagotomy or by deoxycorticosterone acetate and antidiuretic hormone administration. The control values of these dogs were low and indicated a state of peripheral vascular pooling which was readjusted to normal by the immersion maneuver. The renal and hemodynamic values during the period of immersion were similar to values of a group of dogs which were recumbent in air. Furthermore, when the latter group of dogs were tilted head down 19 degrees, there was no further increase in any of the measured parameters. These data are consistent with the view that water immersion in the upright dog simply redistributes blood volume back to that level seen in the recumbent dog, a position which is more natural for this species.


1989 ◽  
Vol 66 (2) ◽  
pp. 792-799 ◽  
Author(s):  
G. Geelen ◽  
S. E. Kravik ◽  
A. Hadj-Aissa ◽  
G. Leftheriotis ◽  
M. Vincent ◽  
...  

To investigate the effects of lower body positive pressure (LBPP) on kidney function while controlling certain cardiovascular and endocrine responses, seven men [35 +/- 2 (SE) yr] underwent 30 min of sitting and then 4.5 h of 70 degrees head-up tilt. An antigravity suit was applied (60 Torr legs, 30 Torr abdomen) during the last 3 h of tilt. A similar noninflation experiment was conducted where the suited subjects were tilted for 3.5 h. To provide adequate urine flow, the subjects were hydrated during the course of both experiments. Immediately after inflation, mean arterial pressure increased by 8 +/- 3 Torr and pulse rate decreased by 16 +/- 3 beats/min. Plasma renin activity and aldosterone were maximally suppressed (P less than 0.05) after 2.5 h of inflation. Plasma vasopressin decreased by 40–50% (P less than 0.05) and plasma sodium and potassium remained unchanged during both experiments. Glomerular filtration rate was not increased significantly by inflation, whereas inflation induced marked increases (P less than 0.05) in effective renal plasma flow (ERPF), urine flow, osmolar and free water clearances, and total and fractional sodium excretion. No such changes occurred during control. Thus, LBPP induces 1) a significant increase in ERPF and 2) significant changes in kidney excretory patterns similar to those observed during water immersion or the early phase of bed rest, situations that also result in central vascular volume expansion.


1994 ◽  
Vol 77 (4) ◽  
pp. 1919-1925 ◽  
Author(s):  
S. Nakamitsu ◽  
S. Sagawa ◽  
K. Miki ◽  
F. Wada ◽  
K. Nagaya ◽  
...  

Effects of water temperature on diuresis, natriuresis, and associated endocrine responses during head-out immersion were studied in eight men (23.4 +/- 0.3 yr) during four 5-h experimental conditions: air control at 28 degrees C and immersion at 34.5 degrees C [thermoneutral (Tnt)], 36 degrees C [above Tnt (aTnt)], and 32 degrees C [below Tnt (bTnt)]. Esophageal temperature decreased by approximately 0.4 degrees C in bTnt and increased by approximately 0.5 degrees C in aTnt. Cardiac output increased by approximately 80% in aTnt and approximately 40% in bTnt while thoracic impedance, an index of central blood pooling, decreased by 7.5 omega in bTnt (NS vs. Tnt) and 8.8 omega in aTnt (P < 0.05 vs. Tnt and bTnt). Total peripheral resistance decreased at all temperatures (50% in aTnt, 20% in bTnt). Urine flow and Na+ excretion increased by sixfold in bTnt and Tnt but by only threefold in aTnt. Creatinine clearance was unchanged while osmolal clearance (but not free water clearance) increased two-fold with all immersions. Plasma atrial natriuretic peptide (ANP), urinary urodilatin, and urinary guanosine 3′,5′-cyclic monophosphate increased while plasma renin activity, aldosterone, and arginine vasopressin (AVP) decreased similarly at all temperatures. bTnt did not potentiate diuresis by selective attenuation of AVP. The overall natriuretic response exhibited a higher correlation with urodilatin (r = 0.45, P < 0.001) than with ANP (r = 0.26, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)


2010 ◽  
Vol 88 (12) ◽  
pp. 1191-1201 ◽  
Author(s):  
S. Mostafa Shid Moosavi ◽  
Masoud Haghani

The exact mechanism underlying thiazides-induced paradoxical antidiuresis in diabetes insipidus is still elusive, but it has been hypothesized that it is exerted either via Na+-depletion activating volume-homeostatic reflexes to decrease distal delivery, or direct stimulation of distal water reabsorption. This study examined how these two proposed mechanisms actually cooperate to induce an acute bendroflumethiazide (BFTZ)-antidiuretic effect in nephrogenic diabetes insipidus (NDI). Anaesthetized rats with lithium (Li)-induced NDI were prepared in order to measure their renal functional parameters, and in some of them, bilateral renal denervation (DNX) was induced. After a 30 min control clearance period, we infused either BFTZ into 2 groups, NDI+BFTZ and NDI/DNX+BFTZ, or its vehicle into a NDI+V group, and six 30 min experimental clearance periods were taken. During BFTZ infusion in the NDI+BFTZ group, transiently elevated Na+ excretion was associated with rapidly increased urinary osmolality and decreased free water clearance, but Li clearance and urine flow declined in the later periods. However, in the NDI/DNX+BFTZ group, there was persistently elevated Na+ excretion with unchanged Li clearance and urine flow during the experimental period, while alterations in free water clearance and urinary osmolality resembled those in the NDI+BFTZ group. In conclusion, BFTZ initially exerted two direct effects of natriuresis–diuresis and stimulating free water reabsorption at the distal nephron in NDI, which together elevated Na+ excretion and urinary osmolality but kept the urine volume unchanged in the first hour. Thereafter, the resultant sodium depletion led to the activation of neural reflexes that reduced distal fluid delivery to compensate for BFTZ-induced natriuresis–diuresis which, in cooperation with the direct distal BFTZ-antidiuretic effect, resulted in excretion of urine with a low volume, high osmolality, and normal sodium.


1993 ◽  
Vol 74 (5) ◽  
pp. 2166-2173 ◽  
Author(s):  
N. V. Olsen ◽  
J. M. Hansen ◽  
I. L. Kanstrup ◽  
J. P. Richalet ◽  
P. P. Leyssac

Renal function was investigated in eight normal subjects before and during infusion of dopamine (3 micrograms.kg-1 x min-1) at sea level (SL) and at high altitude (HA, 4,350 m). Lithium clearance (CLi) was used as an index of proximal tubular outflow. HA significantly increased arterial pressure, heart rate, and plasma norepinephrine. Effective renal plasma flow (ERPF) decreased at HA by 10% (P < 0.05), but glomerular filtration rate (GFR), CLi, sodium clearance (CNa), and urine flow remained unchanged compared with SL. Dopamine at SL and HA increased ERPF by 47% (P < 0.001) and 30% (P < 0.01), respectively, but the increase at HA was smaller than that at SL (P < 0.05). Dopamine increased GFR only at SL. CLi and CNa increased by 29% (P < 0.001) and 108% (P < 0.001) at SL and by 23% (P < 0.01) and 108% (P < 0.001) at HA. Whereas dopamine at SL increased urine flow by 46% (P < 0.01), this response was abolished at HA, and free water clearance decreased (P < 0.05). The decreased ERPF at HA suggests a constriction of the renal arterioles secondary to increased adrenergic nervous activity. Although the effect of dopamine on ERPF was attenuated in hypoxia, dopamine-induced increases in CLi and CNa remained unaltered, suggesting that natriuresis in both environments was secondary to an increased outflow from the proximal tubules. The absence of a diuretic response to dopamine at HA seemed to be caused by an effect on distal tubular function.


1987 ◽  
Vol 253 (2) ◽  
pp. R242-R253 ◽  
Author(s):  
G. Hajduczok ◽  
K. Miki ◽  
S. K. Hong ◽  
J. R. Claybaugh ◽  
J. A. Krasney

The circulatory, renal, and hormonal responses during 100 min of thermoneutral (37 degrees C) head-out water immersion (WI) were investigated in conscious intact (INT) and cardiac-denervated (CD) dogs. In the INT group, both left and right atrial and aortic transmural distending pressures and left ventricular contractile performance (LV dP/dtmax) increased, and total peripheral resistance remained unchanged. Cardiac output (QCO) increased in association with an increase in heart rate and LV dP/dtmax. Urine flow (V), sodium excretion (UNaV), and osmolal clearance (Cosmol) all increased, whereas glomerular filtration rate, as indicated by creatinine clearance (CCr), remained constant. The diuresis and natriuresis occurred in the absence of any significant changes in plasma levels of antidiuretic hormone (ADH), aldosterone, or plasma renin activity. The CD animals showed a similar hemodynamic response except that the increase in QCO was now associated with an increase in stroke volume and no change in heart rate or LV dP/dtmax. Although the increase in V was similar in both magnitude and time course of the INT animals, there was no significant change in UNaV. Thus there is a striking change in the character of the response of the denervated group in that the natriuresis is abolished and, instead, a water diuresis occurred. Free water clearance increased, but no significant changes in Cosmol or CCr were observed. In addition plasma ADH levels significantly declined during WI in the CD group. These data indicate that cardiac receptors are important in determining the nature of the renal response to WI.


1994 ◽  
Vol 112 (2) ◽  
pp. 551-554 ◽  
Author(s):  
Ricardo Marques Dias ◽  
Carlos Stabile ◽  
Pedro Dotto ◽  
José Roberto Jardim

In order to analyze the effect of intermittent negative pressure ventilation (NPV) on renal function, we studied 20 healthy male volunteers (mean age 29±4.1 years). NPV was performed with an "Emerson Chest Respirator Pump", adjusted to a breathing frequency of 10 respirations per minute, with inspiratory time/total respiratory time ratio of 0.4 and negative pressure of 25 cmH2O. The experimental protocol was carried out in two phases of two hours each - spontaneous breathing and NPV breathing. At the end of each phase, urine volume of the whole period was collected as well as venous blood sample for biochemical determinations. During NPV there was significant increase (P<0.05) in urine flow rate (1.43±0.81 to 2.76±1.95 ml/min) as well as in natriuresis (258±201 to 389±175 mcEq/min), kaliuresis (61±45 to 98±49 mcEq/min), fractional sodium excretion (1.38±0.88 to 1.96±0.98%), osmolar clearance (3.13±1.82 to 4.32±1.24 ml/min) and pH (7.37± 0.04 to 7.41±0.07) with unchanged creatinine and free water clearances. We concluded that NPV increases urine flow rate, kaliuresis and natriuresis but the data we have do not allow us to explain the mechanisms underlying such a phenomenon.


1995 ◽  
Vol 268 (4) ◽  
pp. R1040-R1049 ◽  
Author(s):  
K. H. McKeever ◽  
L. C. Keil ◽  
H. Sandler

Eleven anesthetized rhesus monkeys were used to study cardiovascular, renal, and endocrine alterations associated with 120 min of head-out water immersion. Five animals underwent complete intrapericardial denervation using the Randall technique, while the remaining six monkeys served as intact controls. Each animal was chronically instrumented with an electromagnetic flow probe on the ascending aorta, a strain gauge pressure transducer implanted in the apex of the left ventricle (LV), and electrocardiogram leads anchored to the chest wall and LV. During immersion, LV end-diastolic pressure, urine flow, glomerular filtration rate, sodium excretion, and circulating atrial natriuretic peptide (ANP) each increased (P < 0.05) for intact and denervated monkeys. There were no alterations in free water clearance in either group during immersion, yet fractional excretion of free water increased (P < 0.05) in the intact monkeys. Plasma renin activity (PRA) decreased (P < 0.05) during immersion in intact monkeys but not the denervated animals. Plasma vasopressin (PVP) concentration decreased (P < 0.05) during the first 30 min of immersion in both groups but was not distinguishable from control by 60 min of immersion in denervated monkeys. These data demonstrate that complete cardiac denervation does not block the rise in plasma ANP or prevent the natriuresis associated with head-out water immersion. The suppression of PVP during the first minutes of immersion after complete cardiac denervation suggests that extracardiac sensing mechanisms associated with the induced fluid shifts may be responsible for the findings.


1989 ◽  
Vol 76 (1) ◽  
pp. 13-18 ◽  
Author(s):  
K. Yamada ◽  
K. Hasunuma ◽  
T. Shiina ◽  
K. Ito ◽  
Y. Tamura ◽  
...  

1. Physiological saline solution was infused in nine normal subjects and six patients with central diabetes insipidus (DI). At 120 min after the start of infusion, arginine vasopressin (AVP) was injected intramuscularly. Urine was collected in 30 min fractions before and after AVP administration. 2. The urinary excretions of kallikrein-like activity (KAL-A) (S-2266 hydrolysis activity) and immunoreactive kinins (i-kinins) were significantly lower in patients with DI than in normal subjects before AVP administration, while there were no differences in plasma renin activity, plasma aldosterone concentration, creatinine clearance and blood pressure between the two groups, except for a marked water diuresis in patients with DI. The urinary excretion of KAL-A and i-kinins correlated positively with the urinary excretion of AVP. 3. AVP administration increased both plasma AVP and urinary excretion of AVP to similar levels in both groups. As a result, urine volume decreased to a greater degree in patients with DI than in normal subjects. In contrast, the urinary excretions of KAL-A and i-kinins were increased by AVP administration, with a greater response in normal subjects than in the patients with DI. 4. After overnight fasting, acute water loading was carried out orally for 15 min in six normal subjects. At 30 min plasma AVP was suppressed by water loading to almost the basal level found in patients with DI. Urinary excretions of KAL-A and i-kinins in the first 30 min fraction after loading were also suppressed to the basal level in patients with DI. Later, the urinary excretion of KAL-A increased together with the increase in urine flow. Urine volume and free water clearance markedly increased except in the first 30 min fraction, compared with the control period. 5. Thus it is suggested that AVP is one of the factors regulating the renal kallikrein-kinin system in man, although it seems likely that urine flow is still a major factor in urinary kallikrein-kinin excretion.


1994 ◽  
Vol 77 (6) ◽  
pp. 2832-2839 ◽  
Author(s):  
A. S. Larsen ◽  
L. B. Johansen ◽  
C. Stadeager ◽  
J. Warberg ◽  
N. J. Christensen ◽  
...  

The purpose of this experiment was to investigate whether a graded increase in cardiac distension induced by graded water immersion (WI) could be related to endocrine responses and renal sodium excretion (UNaV). On 3 separate days, nine healthy males were investigated in the upright seated position before, during, and after 3 h of WI to the midchest (CI) or to the neck (NI) or during control. Central venous pressure increased twice as much during NI as during CI. UNaV increased to the same extent during NI compared with CI, whereas urine flow rate, solute-free water clearance, and osmotic excretion increased more during the 2nd h of NI than during CI. During NI, the plasma concentration of atrial natriuretic peptide (ANP) increased twice as much as during CI. The plasma concentrations of aldosterone and norepinephrine were decreased in a similar manner during NI compared with CI. In conclusion, graded cardiac distension induced by graded WI and accompanied by a graded release of ANP was not accompanied by a graded increase in UNaV. Thus either a cardiac distension pressure of approximately one-half of that during NI is enough to induce a maximum UNaV during WI or other stimuli are important. Furthermore, aldosterone and norepinephrine are probably more important mediators of the natriuresis of WI in humans than is ANP.


Sign in / Sign up

Export Citation Format

Share Document