Effect of water temperature on diuresis-natriuresis: AVP, ANP, and urodilatin during immersion in men

1994 ◽  
Vol 77 (4) ◽  
pp. 1919-1925 ◽  
Author(s):  
S. Nakamitsu ◽  
S. Sagawa ◽  
K. Miki ◽  
F. Wada ◽  
K. Nagaya ◽  
...  
Keyword(s):  
Water Temperature ◽  
Peripheral Resistance ◽  
Free Water ◽  
Plasma Renin ◽  
Urine Flow ◽  
Thoracic Impedance ◽  
Esophageal Temperature ◽  
Experimental Conditions ◽  
Free Water Clearance ◽  
Air Control

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)

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 ◽  
...  
Keyword(s):  
Water Immersion ◽  
Urine Volume ◽  
Systolic Pressure ◽  
Free Water ◽  
Plasma Renin ◽  
Normal Subjects ◽  
Urine Flow ◽  
Cervical Cord ◽  
Free Water Clearance ◽  
Normal Men

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)

Role of cardiac nerves in response to head-out water immersion in conscious dogs

1987 ◽  
Vol 253 (2) ◽  
pp. R242-R253 ◽  
Author(s):  
G. Hajduczok ◽  
K. Miki ◽  
S. K. Hong ◽  
J. R. Claybaugh ◽  
J. A. Krasney
Keyword(s):  
Heart Rate ◽  
Time Course ◽  
Water Immersion ◽  
Peripheral Resistance ◽  
Free Water ◽  
Plasma Renin ◽  
Left Ventricular ◽  
Right Atrial ◽  
Free Water Clearance ◽  
Striking Change

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.

Cardiovascular, renal, and endocrine responses to intravenous endothelin in conscious dogs

1988 ◽  
Vol 255 (6) ◽  
pp. R1064-R1068 ◽  
Author(s):  
K. L. Goetz ◽  
B. C. Wang ◽  
J. B. Madwed ◽  
J. L. Zhu ◽  
R. J. Leadley
Keyword(s):  
Vascular Endothelial Cells ◽  
Peripheral Resistance ◽  
Free Water ◽  
Urine Osmolality ◽  
Urinary Sodium Excretion ◽  
Conscious Dogs ◽  
Plasma Norepinephrine ◽  
Vascular Endothelial ◽  
Free Water Clearance ◽  
Physiological Processes

Endothelin is a recently discovered vasoconstrictor peptide that is synthesized in certain vascular endothelial cells. We have identified the cardiovascular, renal, and hormonal responses that can be elicited in conscious dogs by intravenous administration of endothelin at rates of 10 and 30 ng.kg-1.min-1 for 60 min (0.24 and 0.72 nmol.kg-1/1-h infusion). Each dose of endothelin increased total peripheral resistance, arterial pressure, and left atrial pressure and decreased heart rate and cardiac output. Hematocrit increased by 4.8% (NS) and 22.9% (P less than 0.01) in response to the lower and higher infusion rates, respectively. Urinary sodium excretion, urine osmolality, and osmolar clearance decreased and free water clearance increased. The lower dose of endothelin decreased plasma norepinephrine and increased plasma atriopeptin. The higher dose increased plasma levels of vasopressin, renin, aldosterone, norepinephrine, epinephrine, and atriopeptin. The higher infusion rate of the peptide caused one or more brief vomiting episodes in four of five dogs. Although it is not yet known whether endothelin is a circulating hormone, it is clear that this peptide is capable of causing profound cardiovascular, renal, and endocrine alterations in conscious dogs. The possible relevance of these observations to physiological processes and to pathological conditions such as hypertension remains to be established.

Contralateral renal function after unilateral renal vein ligation

1959 ◽  
Vol 197 (5) ◽  
pp. 1093-1096
Author(s):  
Joseph H. Perlmutt
Keyword(s):  
Renal Function ◽  
Renal Vein ◽  
Left Renal Vein ◽  
Free Water ◽  
Urine Osmolality ◽  
Tubular Reabsorption ◽  
Experimental Conditions ◽  
Free Water Clearance ◽  
Excretion Rates ◽  
The Right

The effect of increased pressure in one kidney, produced by ligation of its vein, on contralateral renal function was investigated in eight anesthetized dogs. Kidney function was determined under the same experimental conditions in five dogs, but without renal vein ligation. For the latter group, renal function, on the average, remained reasonably stable. After left renal vein ligation, findings for the right kidney were as follows: a) decreased urine flow, amounting maximally to 9.5–41.4% of control flows; b) slight increase of questionable significance in creatinine clearance; c) inconstant changes in PAH clearance; d) increase in urine osmolality to hypertonic values; e) decrease in solute-free water clearance; f) slight rise of questionable significance in total solute clearance; and g) either no change or inconstant changes in excretion rates Na+ and K+. The data indicate that the oliguria resulted solely from increased renal tubular reabsorption of water, suggesting liberation of antidiuretic hormone as the possible mechanism. Direct nervous influences on tubular reabsorption of water cannot, however, be presently ruled out.

Volume-homeostatic mechanisms in humans during a 12-h posture change

1993 ◽  
Vol 75 (1) ◽  
pp. 349-356 ◽  
Author(s):  
P. Norsk ◽  
C. Stadeager ◽  
L. B. Johansen ◽  
J. Warberg ◽  
P. Bie ◽  
...  
Keyword(s):  
Sodium Excretion ◽  
Venous Pressure ◽  
Free Water ◽  
Plasma Renin ◽  
Arterial Pulse ◽  
Free Water Clearance ◽  
Water Handling ◽  
Renal Sodium Excretion ◽  
Male Subjects ◽  
Peak Value

On one day six male subjects underwent an upright seated (SEAT) study, and on another day they were subjected to a head-down tilt of 3 degrees (HDT). Compared with SEAT, HDT induced prompt increases in central venous pressure (CVP) from -0.5 +/- 0.8 to 8.3 +/- 0.3 mmHg (P < 0.001) and in arterial pulse pressure of 8–18 mmHg (P < 0.001). CVP stabilized after 6 h at levels 2.4–2.8 mmHg below the peak value. Simultaneously, renal sodium excretion gradually increased over the initial 5 h of HDT and stabilized at a level approximately 125 mumol/min over that of SEAT (P < 0.001). Urine flow rate and solute free water clearance increased during the initial 2–6 h of HDT (P < 0.001) but returned to the level of SEAT thereafter. We concluded that CVP is slightly reduced over 12 h of HDT and that a clear temporal dissociation exists between renal sodium and water handling. We suggest that the combined effect of the sustained suppressions of plasma renin activity and plasma aldosterone and norepinephrine concentrations constitutes a mechanism of the increase in renal sodium excretion.

Renal effects of left atrial distension in dogs with chronic congestive heart failure

1979 ◽  
Vol 236 (4) ◽  
pp. H554-H560 ◽  
Author(s):  
I. H. Zucker ◽  
L. Share ◽  
J. P. Gilmore
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Left Atrial ◽  
Free Water ◽  
Urine Flow ◽  
Chronic Congestive Heart Failure ◽  
Balloon Inflation ◽  
Free Water Clearance ◽  
Balloon Distension ◽  
Water Clearance

The renal response to left atrial balloon inflation in normal dogs was compared with that in dogs with chronic congestive heart failure (CHF). CHF was induced by the production of an aortocaval fistula below the level of the renal arteries. CHF dogs showed elevated left ventricular end-diastolic pressure, enlarged hearts, a depression of myocardial contractility, pulmonary edema, ascites, and peripheral edema. They also showed significant decreases in urine flow, creatinine clearance, para-aminohippurate clearance, sodium and potassium excretion, fractional sodium excretion, osmolar clearance, arterial blood pressure, and heart rate. Balloon distension of the left atrium evoked a significant increase in urine flow and free-water clearance in the normal group. The reflex nature of this response was indicated by its blockade after bilateral cervical vagotomy. In contrast, the CHF group did not exhibit significant changes in urine flow or free-water clearance during balloon inflation. Plasma antidiuretic hormone (ADH) was significantly elevated in the CHF group; however, balloon distension reduced plasma ADH in both groups of dogs. Plasma renin activity was significantly elevated in the CHF dogs and was not changed by balloon distension in either group of dogs. It is concluded that animals with high-output CHF do not exhibit the atrial-diuretic reflex in spite of their ability to reduce ADH levels by atrial distension.

Role of distal delivery of filtrate in impaired renal dilution of the hypothyroid rat

1976 ◽  
Vol 230 (3) ◽  
pp. 699-705 ◽  
Author(s):  
UF Michael ◽  
J Kelley ◽  
H Alpert ◽  
CA Vaamonde
Keyword(s):  
Free Water ◽  
Urine Flow ◽  
Distal Nephron ◽  
Sprague Dawley ◽  
Diluting Segment ◽  
Free Water Clearance ◽  
Sprague Dawley Rats ◽  
And Control ◽  
Distal Delivery

Free water clearance (CH2O) was measured during hypotonic saline infusion in Sprague-Dawley and in Brattleboro (DI) rats with 131I-induced hypothyroidism and their age-matched controls. At peak urine flow, which was similar in hypothyroid DI (HDI) and control DI (CDI) rats, inulin clearance (CIn/kg) and CH2O/kg were 23 and 20% (P less than 0.02) lower in HDI. Fractional urine flow and fractional sodium excretion were 30 and 40% (P less than 0.001) higher in HDI. Utilization of distal delivery of filtrate for CH2O, formation was 16% less in HDI (P less than 0.01). Papillary osmolality was not higher in HDI rats. Data in Sprague-Dawley rats were similar to those of the DI rats, indicating that endogenous ADH was effectively suppressed. It is concluded: 1) delivery of filtrate out of the proximal tubule was not diminished in hypothyroid rats in spite of a decrease in CIn; 2) despite a similar delivery of filtrate to the distal diluting site, CH2O formation was less in hypothyroid rats than in controls; 3) these data suggest that a defect in the diluting segment could be unmasked at high rates of filtrate delivered to the distal nephron; 4) this defect could be either due to impaired sodium chloride reabsorption or due to increased backdiffusion of water in the distal nephron.

scholarly journals Hemodynamic phenotyping of transgenic rats with ubiquitous expression of an angiotensin-(1-7)-producing fusion protein

2021 ◽  
Author(s):  
Daniele T Alves ◽  
Luiz F Mendes ◽  
Walkyria Oliveira Sampaio ◽  
Leda Maria de Castro Coimbra Campos ◽  
Maria Aparecida R Vieira ◽  
...  
Keyword(s):  
Blood Flow ◽  
Fusion Protein ◽  
Regional Blood Flow ◽  
Peripheral Resistance ◽  
Free Water ◽  
Renin Angiotensin System ◽  
Sodium Concentration ◽  
Tissue Expression ◽  
Transgenic Rat ◽  
Free Water Clearance

Activation of the angiotensin (Ang) converting enzyme 2/Ang-(1-7)/MAS receptor pathway of the renin-angiotensin system induces protective mechanisms in different diseases.  Herein, we describe the cardiovascular phenotype of a new transgenic rat line (TG7371) that expresses an Ang-(1-7)-producing fusion protein.  The transgene-specific mRNA and the corresponding protein were shown to be present in all evaluated tissues of TG7371 with the highest expression in aorta and brain.  Plasma Ang-(1-7) levels, measured by radioimmunoassay were similar to control SD rats, however high Ang-(1-7) levels were found in the hypothalamus.  TG7371 showed lower baseline mean arterial pressure, assessed in conscious or anesthetized rats by telemetry or short-term recordings, associated with increased plasma ANP and higher urinary sodium concentration.  Evaluation of regional blood flow and hemodynamic parameters with fluorescent microspheres showed a significant increase in blood flow in different tissues (kidneys, mesentery, muscle, spleen, brown fat, heart and skin), with a resulting decreased total peripheral resistance.  TG7371 rats also presented increased cardiac and global sympathetic tone, increased plasma AVP levels and decreased free water clearance.  Altogether, our data show that expression of an Ang-(1-7)-producing fusion protein induced a hypotensive phenotype due to widespread vasodilation and consequent fall in peripheral resistance.  This phenotype was associated with an increase in ANP together with an increase in AVP and sympathetic drive, which did not fully compensate the lower BP.  Here we present the hemodynamic impact of long-term increase in tissue expression of an Ang-(1-7)-fusion protein and provide a new tool to investigate this peptide in different pathophysiological conditions.

Contribution of peripheral pooling to the renal response to immersion in the dog

1978 ◽  
Vol 45 (5) ◽  
pp. 786-790 ◽  
Author(s):  
I. H. Zucker ◽  
J. P. Gilmore
Keyword(s):  
Renal Plasma Flow ◽  
Water Immersion ◽  
Venous Pressure ◽  
Free Water ◽  
Urine Flow ◽  
Peripheral Vascular ◽  
Central Venous ◽  
Free Water Clearance ◽  
Hormone Administration ◽  
Cervical Vagotomy

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.

Antigravity suit inflation: kidney function and cardiovascular and hormonal responses in men

1989 ◽  
Vol 66 (2) ◽  
pp. 792-799 ◽  
Author(s):  
G. Geelen ◽  
S. E. Kravik ◽  
A. Hadj-Aissa ◽  
G. Leftheriotis ◽  
M. Vincent ◽  
...  
Keyword(s):  
Kidney Function ◽  
Renal Plasma Flow ◽  
Water Immersion ◽  
Free Water ◽  
Plasma Renin ◽  
Bed Rest ◽  
Urine Flow ◽  
Positive Pressure ◽  
Plasma Sodium ◽  
Lower Body Positive Pressure

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.

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