Effects of Water-Deprivation on Renal-Function and Plasma Arginine Vasotocin in the Feral Chicken, Gallus-Gallus (Phasianidae)

1991 ◽  
Vol 39 (4) ◽  
pp. 439 ◽  
Author(s):  
JR Roberts
Keyword(s):  
Renal Function ◽  
Water Availability ◽  
Filtration Rate ◽  
Water Deprivation ◽  
Arginine Vasotocin ◽  
Constant Infusion ◽  
Osmotic Minipumps ◽  
Diuretic Hormone ◽  
Infusion Method ◽  
Plasma Arginine

Feral chickens occur on a coral atoll off the coast of Queensland, Australia, where the availability of water is limited. Glomerular filtration rate (GFR) was measured in conscious unrestrained feral chickens by means of osmotic minipumps in fully hydrated birds and in birds subjected to a four-day period of water deprivation. Plasma ionic and osmotic concentrations were measured on each day of the experiment. During water deprivation, body weight decreased and plasma ionic and osmotic concentrations increased. Haematocrit was not significantly affected by dehydration. GFR fell on days 2, 3 and 4 of water deprivation to 62% of hydrated values. The plasma levels of the avian diuretic hormone, arginine vasotocin (AVT), increased by a factor of 2.8 over the period of water deprivation. The sensitivity of release of AVT in the feral chicken is higher than that reported for domestic strains of chickens. This may be related to the ability of the feral strain to survive in regions of limited water availability. GFR was measured also by the 'constant infusion' method, which was not significantly different from GFR measured by osmotic minipumps.

Drawbacks of the constant-infusion technique for measurement of renal function

1995 ◽  
Vol 268 (4) ◽  
pp. F543-F552 ◽  
Author(s):  
B. A. Van Acker ◽  
G. C. Koomen ◽  
L. Arisz
Keyword(s):  
Renal Function ◽  
Steady State ◽  
Plasma Concentrations ◽  
Constant Infusion ◽  
Urinary Recovery ◽  
Infusion Method ◽  
Pah Clearance ◽  
The Difference ◽  
Infusion Technique ◽  
Extrarenal Clearance

We investigated the validity of the steady-state constant infusion method (CIM), in which quantitative urinary recovery and constant plasma concentrations of the solute infused are required. Successive 3-h clearances of inulin and p-aminohippuric acid (PAH) were determined for 27 h in 25 patients with renal disease. Results were compared with the standard method of bladder clearance (StM) and with a modified CIM (ModCIM). The 24-h urinary recovery was incomplete for both inulin and PAH. Mean 24-h ModCIM inulin clearance overestimated StM by 4.5 ml.min-1 x 1.73 m-2 (range 0–9, P < 0.001) independent of the extent of renal impairment and pointed to slow distribution and/or extrarenal clearance of inulin. For PAH, the difference between ModCIM and StM clearance was related to the average PAH clearance by ModCIM and StM (r = 0.78). Furthermore, neither plasma inulin nor PAH became completely constant, because of the circadian rhythm in renal function. In conclusion, the conditions of the steady-state CIM technique are not fulfilled, and the method is not suitable for accurate measurement of inulin and PAH clearance, especially when the clearance is low.

EFFECT OF DEHYDRATION PRODUCED BY WATER DEPRIVATION, DIARRHEA AND VOMITING ON RENAL FUNCTION IN INFANTS

PEDIATRICS ◽  
1951 ◽  
Vol 7 (3) ◽  
pp. 328-340
Author(s):  
PHILIP L. CALCAGNO ◽  
MITCHELL I. RUBIN
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Intravenous Administration ◽  
Water Conservation ◽  
Filtration Rate ◽  
Water Deprivation ◽  
Diarrheal Disease ◽  
Normal Values ◽  
Water Reabsorption

Dehydration when of sufficient severity depresses the glomerular filtration rate significantly. The high inulin and creatinine U/P ratios during dehydration indicate water conservation by the tubules. Depressed glomerular filtration rates may enhance this mechanism. The tendency to the lower than expected rise in U/P ratio with low urine flows during dehydration in diarrheal disease suggests disturbed tubular mechanism for water reabsorption. Glomerular filtration rate is rapidly restored with the intravenous administration of fluid. Restoration to normal values may proceed at a slower pace in the sick infant.

Regulation of plasma arginine vasotocin in conscious water-deprived domestic fowl

1986 ◽  
Vol 250 (4) ◽  
pp. R658-R664 ◽  
Author(s):  
J. N. Stallone ◽  
E. J. Braun
Keyword(s):  
Antidiuretic Hormone ◽  
Fluid Balance ◽  
Intravenous Infusion ◽  
Domestic Fowl ◽  
Water Deprivation ◽  
Extracellular Volume ◽  
Plasma Osmolality ◽  
Arginine Vasotocin ◽  
Plasma Arginine

Radioimmunoassay methods were employed to quantitatively characterize secretion of the avian antidiuretic hormone [arginine vasotocin (AVT)] by the hypothalamo-neurohypophyseal system (HNS) of the conscious domestic fowl in response to chronic dehydration. Water deprivation permitted characterization of AVT secretion in response to the combined stimuli of extracellular hyperosmolality and hypovolemia; the subsequent repletion of extracellular volume permitted separation of potential osmotic and volemic factors involved in the regulation of AVT secretion. In normally hydrated birds, plasma AVT (PAVT) and plasma osmolality (Posm) averaged 2.2 +/- 0.3 microU/ml (10.5 +/- 1.4 pg/ml) and 309.3 +/- 0.7 mosmol/kg H2O, respectively (means +/- SE). With water deprivation, PAVT and Posm of the birds increased in parallel in a curvilinear manner to maxima of 13.1 +/- 0.6 microU/ml (62.4 +/- 2.9 pg/ml) and 346.6 +/- 2.0 mosmol/kg H2O, respectively, at 96 h of dehydration. The isosmotic repletion of extracellular volume at 96 h by acute intravenous infusion failed to alter 96-h PAVT values. The results indicate that AVT secretion is closely linked to the state of hydration during negative fluid balance in the domestic fowl. Analysis of the data indicated that increases in PAVT that occur with dehydration are mediated primarily by extracellular hyperosmolality and that the HNS of the domestic fowl is relatively insensitive to the simultaneous hypovolemia incurred with fluid deprivation.

Glomerular filtration rate in conscious unrestrained starlings under dehydration

1989 ◽  
Vol 256 (4) ◽  
pp. R836-R839 ◽  
Author(s):  
J. R. Roberts ◽  
W. H. Dantzler
Keyword(s):  
Glomerular Filtration Rate ◽  
Sodium Chloride ◽  
Glomerular Filtration ◽  
Local Anesthesia ◽  
Peritoneal Cavity ◽  
Filtration Rate ◽  
Water Deprivation ◽  
Plasma Osmolality ◽  
Osmotic Minipumps ◽  
Calcium Magnesium

Glomerular filtration rate (GFR) was measured in conscious unrestrained starlings, Sturnis vulgaris. Alzet osmotic minipumps were inserted into the peritoneal cavity under lidocaine local anesthesia and served to infuse the GFR marker [14C]sodium ferrocyanide. GFR was measured in hydrated birds and again after a 24-h period of water deprivation. GFR in dehydrated birds was 1.15 +/- 0.09 ml.min-1.kg-1, significantly lower (P less than 0.001) than the 2.71 +/- 0.31 ml.min-1.kg-1 in fully hydrated animals. In addition, the GFR of the hydrated birds was significantly lower (P less than 0.01) than values of 4.43 +/- 0.24 ml.min-1.kg-1 measured in hydrated anesthetized birds during micropuncture studies. A 24-h period of water deprivation caused significant increases in plasma osmolality and concentration of sodium, chloride, and phosphate. The osmolality and concentrations of calcium, magnesium, and phosphate were significantly elevated in both cloacal urine supernatant and in ureteral urine of dehydrated birds. In both hydrated and dehydrated states, the concentration of magnesium, phosphate, potassium, and total osmolality were significantly higher in cloacal urine than in ureteral urine.

Influence of hydration on renal function and medullary sodium during vasopressin infusion

1962 ◽  
Vol 202 (6) ◽  
pp. 1098-1104 ◽  
Author(s):  
Joseph H. Perlmutt
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Filtration Rate ◽  
Urine Flow ◽  
Constant Infusion ◽  
Water Diuresis ◽  
Vasopressin Infusion ◽  
Degree Of Hydration ◽  
Anesthetized Dogs ◽  
Influence Of Hydration

Mild and severe degrees of hydration were produced in anesthetized dogs by constant infusion of dextrose in water at different rates. When water diuresis ensued, and after adequate control periods, vasopressin was infused for 2 1/2 hr. The magnitudes of urine flow and Na excretion varied directly and osmolal urine-to-plasma ratio varied inversely with the degree of hydration. During mild hydration, glomerular filtration rate and osmolal clearance remained practically unchanged, whereas during severe hydration they increased. In another group of animals, similarly prepared, kidneys were removed at appropriate times and tissue was obtained from various areas for Na analysis. During uninterrupted water diuresis the medullary gradient for Na was practically dissipated. Vasopressin promoted the repletion of medullary Na during mild hydration, but only slightly ameliorated the disturbance during severe hydration. These data demonstrate that during vasopressin infusion the renal concentrating response and Na excretion were significantly modified by the degree of hydration, and evidence is presented for several possible causes.

Clinical Renal Function Testing by External Double Isotope Monitoring Technique

1971 ◽  
Vol 10 (01) ◽  
pp. 16-24
Author(s):  
J. Fog Pedersen ◽  
M. Fog Pedersen ◽  
Paul Madsen
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Correlation Coefficients ◽  
Feedback System ◽  
Effective Renal Plasma Flow ◽  
Advantages And Disadvantages

SummaryAn accurate catheter-free technique for clinical determination simultaneouslyof glomerular filtration rate and effective renal plasma flow by means of radioisotopes has been developed. The renal function is estimated by the amount of radioisotopes necessary to maintain a constant concentration in the patient’s blood. The infusion pumps are steered by a feedback system, the pumps being automatically turned on when the radiation measured over the patient’s head falls below a certain preset level and turned off when this level is again readied. 131I-iodopyracet was used for the estimation of effective renal plasma flow and125I-iothalamate estimation of the glomerular filtration rate. These clearances were compared to the conventional bladder clearances and good correlation was found between these two clearance methods (correlation coefficients 0.97 and.90 respectively). The advantages and disadvantages of this new clearance technique are discussed.

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