Morphological and functional comparisons of normal and hypertrophied kidneys of adult domestic fowl (Gallus gallus)

1990 ◽  
Vol 258 (2) ◽  
pp. F403-F413
Author(s):  
C. M. Gregg ◽  
R. F. Wideman
Keyword(s):  
Domestic Fowl ◽  
Renal Mass ◽  
Plasma Osmolality ◽  
Free Water ◽  
Urine Osmolality ◽  
Osmotic Diuresis ◽  
Free Water Clearance ◽  
Permanent Loss ◽  
The Right ◽  
Water Clearance

Similar to mammals, kidneys of domestic fowl undergo compensatory hypertrophy after loss of functional renal mass. Because this species continues to develop new nephrons for up to 12-wk posthatch, renal hyperplasia might play a significant role in compensatory growth. Either transient or permanent loss of approximately 60% of the right kidney was produced in 2- to 3-wk-old roosters by simple ureteral transection or by removing a 1-mm segment of ureter at the level of the ischiadic artery, respectively. In the latter (experimental) group, right anterior and medial divisions atrophied leaving only the posterior division intact. Spontaneous reanastomosis occurred in the former (reconnected) group, and all three divisions were present at death. Control birds were untouched as were the left kidneys of experimental and reconnected birds. At 40-50 wk, renal function was measured separately in right and left kidneys of all groups during five different infusion protocols. Compared with control kidneys, experimental kidneys had a 50-60% weight gain, and their glomerular size distribution profile was shifted to the right (larger glomeruli). Reconnected kidneys were not hypertrophied, and their profile was shifted to the left (smaller glomeruli). Neither group had significant formation of new nephrons. Once variations in kidney weight were taken into account, there were no differences between hypertrophied (experimental) and control kidneys in urine flow rate (UFR), glomerular filtration rate (GFR), paraaminohippuric acid (PAH) clearance, UFR/GFR, urine osmolality, urine/plasma osmolality, osmolal clearance, free water clearance, Na and K load, absolute Na and K excretion, and fractional Na and K excretion except as follows: 1) during infusion of isotonic mannitol-dextrose at 0.1 ml.min-1.kg body wt-1 experimental kidneys had a lower fractional excretion of K than control kidneys, and 2) during brisk osmotic diuresis (isotonic mannitol-dextrose at 0.4 ml.min-1.kg body wt-1) experimental kidneys had higher UFR and free water clearance and lower urine osmolality and urine/plasma osmolality than control kidneys. Reconnected kidneys differed from control kidneys in only 1 of 210 comparisons. Permanent loss of functional renal mass in young birds produces significant compensatory renal hypertrophy that is due to enlargement of existing nephrons rather than formation of new nephrons. Hypertrophied kidneys function like normal kidneys except under conditions of brisk osmotic diuresis.

Osmoregulation of thirst and vasopressin during normal menstrual cycle

1988 ◽  
Vol 254 (4) ◽  
pp. R641-R647 ◽  
Author(s):  
T. J. Vokes ◽  
N. M. Weiss ◽  
J. Schreiber ◽  
M. B. Gaskill ◽  
G. L. Robertson
Keyword(s):  
Menstrual Cycle ◽  
Luteal Phase ◽  
Plasma Osmolality ◽  
Free Water ◽  
Urine Osmolality ◽  
Free Water Clearance ◽  
Vasopressin Release ◽  
Plasma Vasopressin ◽  
Normal Menstrual Cycle ◽  
Basal Plasma

Changes in osmoregulation during normal menstrual cycle were examined in 15 healthy women. In 10 women, studied repetitively during two consecutive menstrual cycles, basal plasma osmolality, sodium, and urea decreased by 4 mosmol/kg, 2 meq/l, and 0.5 mM, respectively (all P less than 0.02) from the follicular to luteal phase. Plasma vasopressin, protein, hematocrit, mean arterial pressure, and body weight did not change. In five other women, diluting capacity and osmotic control of thirst and vasopressin release were assessed in follicular, ovulatory, and luteal phases. Responses of thirst and/or plasma vasopressin, urine osmolality, osmolal and free water clearance to water loading, and infusion of hypertonic saline were normal and similar in the three phases. However, the plasma osmolality at which plasma vasopressin and urine osmolality were maximally suppressed as well as calculated osmotic thresholds for thirst and vasopressin release were lower by 5 mosmol/kg in the luteal than in the follicular phase. This lowering of osmotic thresholds for thirst and vasopressin release, which occurs in the luteal phase, is qualitatively similar to that observed in pregnancy and should be taken into account when studying water balance and regulation of vasopressin secretion in healthy cycling women.

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.

Vasopressin is involved in renal effects of high-protein diet: study in homozygous Brattleboro rats

1991 ◽  
Vol 260 (1) ◽  
pp. F96-F100 ◽  
Author(s):  
N. Bouby ◽  
M. M. Trinh-Trang-Tan ◽  
C. Coutaud ◽  
L. Bankir
Keyword(s):  
Renal Function ◽  
Free Water ◽  
High Protein Diet ◽  
Urine Osmolality ◽  
Urine Concentration ◽  
High Protein ◽  
Brattleboro Rats ◽  
Sprague Dawley ◽  
Free Water Clearance ◽  
Water Clearance

The present study was designed to test the possible role of vasopressin in the renal response to dietary protein. This possibility was suggested by the similarity of effects on renal function and morphology of chronic high-protein intake and chronic stimulation of urine concentration. Adult male Brattleboro rats, genetically unable to produce vasopressin, were fed high-protein (32% casein = HP, n = 8) or low-protein (10% casein = LP, n = 9) diet for 7 wk. Renal function was evaluated by clearance techniques based on 24-h urine collections in metabolic cages. The response to a single injection of the vasopressin analogue 1-desamino-8-D-arginine vasopressin (DDAVP) was also tested. Kidney weight and height of the different renal zones were assessed at the end of the study. HP diet increased urea excretion nearly sevenfold. Water intake increased by 57% (P less than 0.001) and urine flow rate by 71% (P less than 0.01). Urine osmolality rose from 104 to 181 mosmol/kgH2O (P less than 0.001). At variance with what occurs in rats with endogenous vasopressin (Sprague-Dawley; Bouby, N., et al. Kidney Int 34: 4-12, 1988), HP diet increased creatinine clearance per unit body weight by only 14% and did not change free water clearance, renal mass, and height of inner stripe of outer medulla. However, the rise in urine osmolality and drop in free water clearance after DDAVP were significantly greater in HP- than in LP-fed Brattleboro rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Free water excretion in normal dogs

1962 ◽  
Vol 202 (6) ◽  
pp. 1131-1135 ◽  
Author(s):  
E. Lovell Becker ◽  
H. Earl Ginn
Keyword(s):  
Sodium Chloride ◽  
Sodium Sulfate ◽  
Free Water ◽  
Maximal Rate ◽  
Water Diuresis ◽  
Osmotic Diuresis ◽  
Free Water Clearance ◽  
Water Excretion ◽  
Early Increase ◽  
Water Clearance

Free water excretion (Chh2o = V - Cosm) was studied in unanesthetized dogs. This parameter of urine dilution was defined by superimposing an osmotic diuresis upon a water diuresis. Sodium sulfate (1.5%) gave the smallest free water clearance and sodium chloride (0.95%) the greatest, urea (1.65%) and mannitol (5.0%) being intermediary in their effects. Observed free water clearances were never maximal and, when plotted as Cosm vs. V, gave a slope of less than one. Two mercurial diuretics, meralluride and mercaptomerin, gave intermediary values for free water. Meralluride caused an early increase in free water clearance because of the theophylline incorporated in the compound. Later results were similar to those with mercaptomerin, both compounds producing free water clearances approaching a maximal rate.

Regulation and function of arginine vasopressin in pregnant sheep

1986 ◽  
Vol 250 (5) ◽  
pp. F777-F780 ◽  
Author(s):  
R. J. Bell ◽  
B. M. Laurence ◽  
P. J. Meehan ◽  
M. Congiu ◽  
B. A. Scoggins ◽  
...  
Keyword(s):  
Arginine Vasopressin ◽  
Infusion Rate ◽  
Plasma Osmolality ◽  
Free Water ◽  
Urinary Flow ◽  
Free Water Clearance ◽  
Pregnant Sheep ◽  
The Mean ◽  
And Function ◽  
Water Clearance

The aim of this study was to investigate the regulation and function of arginine vasopressin (AVP) in pregnant sheep. The mean plasma osmolality of nonpregnant ewes (298 +/- 1.0 mosmol/kg, n = 8) was not significantly different from that of late pregnant ewes (295 +/- 1.1 mosmol/kg, n = 21). The mean resting plasma [AVP] of nonpregnant ewes (4.1 +/- 0.6 pg/ml,n = 8) was not significantly different from that of pregnant ewes (3.3 +/- 0.3 pg/ml,n = 21). In a series of dehydration experiments it was established that the slope of the function relating log [AVP] to plasma osmolality for pregnant ewes (n = 13) was not significantly different from the slope of the function relating log [AVP] to plasma osmolality for nonpregnant ewes (n = 4). When AVP was infused into water-loaded ewes, a significant decrease in urinary flow rate and free water clearance occurred at an infusion rate of 0.003 microgram/h in both the pregnant (n = 4) and nonpregnant (n = 4) animals. Both groups achieved negative free water clearance at an infusion rate of 0.01 microgram/h. These findings suggest that pregnancy does not alter the relationship between plasma osmolality and plasma [AVP] or the renal responsiveness to AVP in sheep.

Body fluid balance in dehydrated healthy older men: thirst and renal osmoregulation

1994 ◽  
Vol 76 (4) ◽  
pp. 1615-1623 ◽  
Author(s):  
G. W. Mack ◽  
C. A. Weseman ◽  
G. W. Langhans ◽  
H. Scherzer ◽  
C. M. Gillen ◽  
...  
Keyword(s):  
Body Fluid ◽  
Fluid Intake ◽  
Plasma Osmolality ◽  
Free Water ◽  
Older Individuals ◽  
Total Fluid Intake ◽  
Free Water Clearance ◽  
Stimulus Response ◽  
Response Characteristics ◽  
Water Clearance

We examined osmotic control of thirst and free water clearance in healthy older (65+, n = 10) and younger (Y, n = 6) subjects during a 3-h rehydration period after an approximately 2.4% decrease in body weight. Plasma volume (PV), plasma osmolality (Posm), renal function, and thirst were measured before and after dehydration and during rehydration. In 65+, baseline PV was lower (43.1 +/- 1.6 vs. 48.1 +/- 2.5 ml/kg), Posm was higher (287 +/- 1 vs. 281 +/- 2 mosmol/kgH2O), and perceived thirst was lower than in Y. During dehydration, the osmotic threshold for increased thirst was shifted to a higher Posm in 65+. Total fluid intake was greater in Y than in 65+ (16.6 +/- 4.1 vs. 8.9 +/- 2.0 ml/kg); however, the relation between thirst and the rate of fluid intake was identical. Thus the blunted rehydration in 65+ is related to a lower overall sensation of thirst. The stimulus-response characteristics of osmotic control of free water clearance was similar in 65+ and Y; however, 65+ operated around a higher Posm and on a less-steep portion of the stimulus-response curve. These data support the hypothesis that the hyperosmotic hypovolemic state of healthy older individuals is not a result of a simple water deficit but represents a shift in the operating point for control of body fluid volume and composition.

Antidiuretic response to electrical stimulation in brain stem of the monkey

1964 ◽  
Vol 206 (1) ◽  
pp. 15-20 ◽  
Author(s):  
James N. Hayward ◽  
Wilbur K. Smith
Keyword(s):  
Electrical Stimulation ◽  
Brain Stem ◽  
Red Nucleus ◽  
Isotonic Saline ◽  
Free Water ◽  
Urine Osmolality ◽  
Mesencephalic Reticular Formation ◽  
Free Water Clearance ◽  
Stimulation Of ◽  
Water Clearance

Antidiuretic hormone release was produced in conscious monkeys by electrical excitation of certain regions in the brain stem. The experimental design allowed repeated control and test observations in the same animal over a period of months. Alterations in free water clearance and urine osmolality resulted from electrical stimulation of the hypothalamus, the mesencephalic reticular formation, the ventral tegmental area of Tsai, and the periaqueductal gray substance. A similar drop in free water clearance and a rise in urine osmolality without a change in glomerular filtration rate was observed in the same animals after intravenous infusion of vasopressin. No significant changes in free water clearance or in urine osmolality were observed during the taking of blood samples, the infusion of isotonic saline or of 5% dextrose, or as a result of stimulation of the dorsolateral hypothalamus, thalamus, red nucleus, tectum, pons, and the optic chiasm.

Effect of ethanol ingestion on plasma vasopressin and water balance in humans

1982 ◽  
Vol 242 (5) ◽  
pp. R522-R527 ◽  
Author(s):  
G. Eisenhofer ◽  
R. H. Johnson
Keyword(s):  
Hypertonic Saline ◽  
Free Water ◽  
Urine Osmolality ◽  
Saline Infusion ◽  
Ethanol Ingestion ◽  
Free Water Clearance ◽  
Vasopressin Release ◽  
Plasma Vasopressin ◽  
Hypertonic Saline Infusion ◽  
Water Clearance

The effects of 75 ml ethanol ingested over 60 min on plasma osmolality (Posmol) and plasma vasopressin (PAVP) in four normal subjects were studied. In the 1st h of the investigation PAVP fell, then rose, even though plasma ethanol levels were still rising. The rise in PAVP was preceded by a rise in Posmol corrected for the influence of ethanol. The fall in PAVP was followed by an increase in free water clearance and a decrease in urine osmolality, while the later rise in PAVP was followed by a decrease in free water clearance (CH2O) and a rise in urine osmolality. The relationship between PAVP and Posmol was then studied during intravenous (iv) hypertonic saline infusion in five subjects. The results were compared with those from a second infusion in the same subjects after ingestion of ethanol (0.5 ml/kg). Ethanol reduced vasopressin release in response to iv hypertonic saline infusion, and this correlated with a reduced decrease in CH2O. We conclude that ethanol inhibits PAVP release by decreasing the response of the osmosodium receptors to changes in plasma tonicity.

Osmotic thresholds for AVP release with the use of plasma and urine AVP and free water clearance

1989 ◽  
Vol 256 (4) ◽  
pp. R892-R897 ◽  
Author(s):  
A. M. Moses
Keyword(s):  
Plasma Osmolality ◽  
Free Water ◽  
Normal Subjects ◽  
Free Water Clearance ◽  
Linear Relationships ◽  
Osmotic Stimulation ◽  
Glomerular Filtrate ◽  
The Mean ◽  
The Relationship ◽  
Water Clearance

Eleven hydrated normal subjects were infused with hypertonic saline so that plasma osmolalities (POsmol) ranged from 280 to 306 mosmol/kg. Linear relationships were calculated between POsmol and plasma and urine arginine vasopressin (AVP) in the 11 individual subjects. There was an excellent linear correlation between POsmol and plasma and urine AVP, with the latter as concentration or rate of excretion. The highest correlation coefficient occurred when urine AVP was expressed as microunits of AVP per 100 milliliters of glomerular filtrate. The smallest coefficient of variation of the slopes occurred when urine AVP was expressed as microunits of AVP per minute. The osmotic thresholds obtained by abscissal intercepts from relating POsmol to urine AVP per minute or per 100 milliliters of glomerular filtrate were 285.9 and 285.5 mosmol/kg, respectively. These values did not differ from the mean osmotic threshold obtained by traditional free water clearance changes (285.8 mosmol/kg). Analysis of the relationship between plasma osmolality and plasma AVP resulted in the greatest variation in slope and osmotic threshold, with the latter being significantly lower than that obtained by free water clearance changes. The data also demonstrated a much more rapid rise of urine than of plasma AVP under the stated conditions of osmotic stimulation.

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