Vasopressin contamination as a cause of some apparent renal actions of prolactin

1976 ◽  
Vol 54 (6) ◽  
pp. 887-890 ◽  
Author(s):  
R. Keeler ◽  
N. Wilson
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Urine Output ◽  
Filtration Rate ◽  
Urine Osmolality ◽  
Brattleboro Rats ◽  
Urine Excretion ◽  
Renal Effects ◽  
Antidiuretic Activity ◽  
Electrolyte Retention

The injection or infusion of NIAMDD prolactin (NIH P-S-10) into unanesthetized rats resulted in water and electrolyte retention with a large increase in urine osmolality but no effect on glomerular filtration rate. Since these effects on urine output were also observed in homozygous Brattleboro rats, the antidiuretic activity could not have been caused by the release of endogenous antidiuretic hormone.Radioimmunoassay of NIH prolactin showed that it was contaminated with vasopressin (20 ng/mg of prolactin). By comparison, Sigma prolactin had no observed effect on urine excretion and contained very little vasopressin (2.5 ng/mg).It is concluded that some of the renal effects of prolactin that have been reported in the literature may have been caused by the contaminating vasopressin.

Micropuncture study of the superficial nephron of Perognathus penicillatus

1981 ◽  
Vol 241 (6) ◽  
pp. F612-F617
Author(s):  
E. J. Braun ◽  
D. R. Roy ◽  
R. L. Jamison
Keyword(s):  
Glomerular Filtration Rate ◽  
Proximal Tubule ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Distal Tubule ◽  
Urine Osmolality ◽  
Small Rodent ◽  
Micropuncture Study ◽  
Single Nephron ◽  
Average Body

A micropuncture study of Perognathus penicillatus, a small rodent native to the deserts of the southwestern United States was performed to evaluate the function of the superficial nephron. Data are reported for 12 animals of 17 g average body wt. Mean glomerular filtration rate was 475 +/- 73 microliter X min-1 X g kidney wt-1. Urine osmolality averaged 1,154 +/- 197 mosmol/kg H2O. Single nephron glomerular filtration rate averaged 43 nl X min-1 X g kidney wt-1 in the proximal tubule and 48 in the distal tubule, values that are not significantly different. In terms of the filtered load remaining unreabsorbed at the end of the accessible proximal tubule, the average percentages were 46 water, 48 total solute, 45 sodium, 56 phosphorus, 62 potassium, 71 magnesium, and 54 calcium. The concentrations of potassium and magnesium in fluid samples increased significantly along the proximal tubule. Approximately at the midpoint of the distal tubule, fractional delivery of water, 13.1%, was greater than that for total solute, 10%, or sodium, 7%, indicating that the intervening segment of nephron reabsorbed solute and sodium in excess of water. The function of the superficial nephron resembles that of species previously investigated except for potassium reabsorption in the proximal convoluted tubule.

Meclofenamate and urine concentration with and without exposure of the renal papilla

1981 ◽  
Vol 240 (5) ◽  
pp. F423-F429 ◽  
Author(s):  
R. J. Roman ◽  
C. Lechene
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Urine Osmolality ◽  
Urine Concentration ◽  
Prostaglandin Synthesis ◽  
Urine Flow ◽  
Renal Papilla ◽  
Arterial Blood ◽  
Pelvic Urine

The recent finding that inhibitors of prostaglandin synthesis prevent the fall in urine concentration produced by papillary exposure challenges the hypothesis that contact between the pelvic urine and papilla is essential to the renal concentrating process. The present study examines the change in urine osmolality produced by exposure of the renal papilla in rats given meclofenamate. In control animals urine osmolality(Uosmol) decreased 57% after 2 h of exposure of the renal papilla. In rats given meclofenamate 4 mg/kg urine osmolality increased 16%, urine flow decreased 30%, and glomerular filtration rate was unchanged in the nonexposed kidney. Meclofenamate, however, did not alter the decrease in Uosmol seen in the kidney with the exposed papilla. Meclofenamate 10 mg/kg was also ineffective in preventing the fall in urine osmolality produced by papillary exposure, although this higher dose decreased glomerular filtration rate and arterial blood pressure. These results are consistent with the finding that pelvic urine urea is important to the urinary concentrating process and with the hypothesis that urine osmolality falls after papillary exposure because contact between pelvic urine and papilla is interrupted.

Angiotensin II modulates the intrarenal effects of atrial natriuretic peptide

1988 ◽  
Vol 255 (3) ◽  
pp. F545-F551
Author(s):  
H. M. Siragy ◽  
N. E. Lamb ◽  
C. E. Rose ◽  
M. J. Peach ◽  
R. M. Carey
Keyword(s):  
Glomerular Filtration Rate ◽  
Angiotensin Ii ◽  
Atrial Natriuretic Peptide ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Systemic Effects ◽  
Ang Ii ◽  
Renal Effects

The mechanism by which atrial natriuretic peptide (ANP) increases renal water and solute excretion is not fully understood. We studied the renal effects of ANP and angiotensin II (ANG II) separately and together in uninephrectomized conscious dogs (n = 7) in sodium metabolic balance (80 meq/day). Exogenous ANG II and ANP were without measurable systemic effects as demonstrated by absence of changes in blood pressure, plasma aldosterone concentration, and plasma renin activity. The quantity of ANG II that had significant renal effects that were without measurable systemic effects was 0.2 pmol.kg-1.min-1. Three infusion rates of ANP had significant renal effects (1, 10, and 20 pmol.kg-1.min-1). These quantities of ANP caused significant diuresis, natriuresis, kaliuresis, and increased glomerular filtration rate without significant changes in renal plasma flow. ANG II alone caused significant antidiuresis, antinatriuresis, and decreased glomerular filtration rate and renal plasma flow. When ANG II and ANP were given together, no change in urinary flow rate, urinary sodium or potassium excretion, or renal plasma flow was observed, whereas glomerular filtration rate increased. Filtration fraction increased significantly with ANG II and ANP separately and together. Intrarenal ANP prevents the ANG II-induced decrement in urinary sodium excretion and urine flow rate. ANP may play an important role in escape from the sodium-retaining action of intrarenal ANG II.

Cisplatin nephrotoxicity in rats: defect in papillary hypertonicity

1981 ◽  
Vol 241 (2) ◽  
pp. F175-F185 ◽  
Author(s):  
R. Safirstein ◽  
P. Miller ◽  
S. Dikman ◽  
N. Lyman ◽  
C. Shapiro
Keyword(s):  
Glomerular Filtration Rate ◽  
Proximal Tubule ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Collecting Duct ◽  
Urine Volume ◽  
Distal Tubule ◽  
Urine Osmolality ◽  
Solute Content ◽  
Cisplatin Nephrotoxicity

We examined the effects of cisplatin (5 mg/kg BW) on renal function in rats. Three days after administration of cisplatin whole kidney clearance of inulin fell and 24-h urine volume increased. Maximal urine osmolality and papillary solute content were reduced. Superficial nephron glomerular filtration rate measured along the proximal tubule, where no leak of inulin could be demonstrated, was reduced in cisplatin-treated animals. Differences between superficial nephron glomerular filtration rate determined in proximal and distal tubules were greater in cisplatin-treated rats than in control rats. Neither a change in fluid or sodium movement along superficial nephrons nor a reduced early distal tubule transepithelial sodium gradient explain the polyuria. Urea was reabsorbed from, not added to, the loop fluid in cisplatin-treated animals. Morphologic changes were evident in the S3 segment of the proximal tubule in cisplatin-treated animals but the glomeruli were normal. Polyuria occurred despite diminished glomerular filtration rate in cisplatin nephrotoxicity. The diminished concentration of salt and urea in the papilla as a result of abnormal function of the collecting duct or pars recta portion of the proximal tubule contributed to the defect in concentrating ability.

Localization of alpha 2-adrenoceptor-mediated increase in renal Na+, K+, and water excretion

1987 ◽  
Vol 252 (6) ◽  
pp. F1016-F1021 ◽  
Author(s):  
B. Stanton ◽  
E. Puglisi ◽  
M. Gellai
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Water Transport ◽  
Filtration Rate ◽  
Distal Tubule ◽  
Fractional Excretion ◽  
Urine Osmolality ◽  
Water Excretion ◽  
Arterial Blood ◽  
Adrenoceptor Agonist

Free-flow micropuncture and clearance studies were conducted in male Sprague-Dawley rats to investigate the effects of alpha 2-adrenoceptor stimulation on Na+, K+, and water transport along the nephron. Intravenous infusion of the selective alpha 2-adrenoceptor agonist B-HT 933 at 1 mg X kg-1 X h-1 increased urinary flow rate from 16.2 +/- 3.6 to 84.8 +/- 11.9 microliter/min, fractional excretion of Na+ from 1.36 +/- 0.31 to 3.57 +/- 0.52%, and fractional excretion of K+ from 26.9 +/- 3.0 to 42.3 +/- 2.2%, The diuresis, saluresis, and kaliuresis were not the result of increases in glomerular filtration rate or mean arterial blood pressure. Urine osmolality decreased from 1,126 +/- 177 to 325 +/- 33 mosmol/kg water and in 8 of the 11 animals studied B-HT 933 decreased urine osmolality to hyposmotic levels, suggesting a possible interaction between the alpha 2-adrenoceptor agonist and vasopressin. The alpha 2-adrenoceptor antagonist yohimbine (0.25/mg bolus, iv) inhibited the diuresis, saliuresis, and kaliuresis. In micropuncture studies, B-HT 933 was without effect on single-nephron glomerular filtration rate or on Na+, K+, and water transport along the superficial proximal tubule, loop of Henle, or distal tubule. Thus stimulation of alpha 2-adrenoceptors increases Na+, K+, and water excretion by inhibiting tubule reabsorption of these substances at nephron sites beyond the superficial distal tubule, most likely by the collecting tubule.

Renal Function Correlates of Postnatal Diuresis in Preterm Infants

PEDIATRICS ◽  
1988 ◽  
Vol 82 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Khurshid S. Bidiwala ◽  
John M. Lorenz ◽  
Leonard I. Kleinman
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Preterm Infants ◽  
Sodium Excretion ◽  
Urine Output ◽  
Filtration Rate ◽  
Fluid Intake ◽  
Intake Rate ◽  
Fractional Sodium Excretion ◽  
The Face

A characteristic pattern of fluid homeostasis occurs in the first week of life in many preterm infants. Initially, urine output is low independent of fluid intake, subsequently a diuresis occurs, and finally urine output begins to vary with intake. Renal clearance measurements were made during each of these three phases to elucidate the renal mechanisms involved. Periods during which the ratio of urine output to fluid intake was ≥1 and urine output was ≥3 mL/kg/h were defined as diuretic. Of 22 preterm infants studied from 12 to 120 hours of age, 17 had at least one period of diuresis. In these infants, urine output, fluid intake rate, output to intake ratio, glomerular filtration rate, and fractional sodium excretion were lowest at 12 to 24 hours of age. During diuresis, urine output tripled without a significant change in fluid intake so that output to intake increased to levels exceeding unity. Diuresis was associated with significant increases in glomerular filtration rate and fractional sodium excretion. By 108 to 120 hours of age, urine output decreased despite an increase in fluid intake. This was accompanied by a decrease in glomerular filtration rate. These results suggest that the initial antidiuretic phase is the result of a low fractional sodium excretion in the face of a low glomerular filtration rate. Subsequently, diuresis and natriuresis occur as a result of abrupt, nonmaturational increases in glomerular filtration rate and fractional sodium excretion. With cessation of diuresis, glomerular filtration rate and fractional sodium excretion decrease and water and electrolyte output begin to vary appropriately with intake.

Glomerular filtration rate in weaned elephant seal pups during natural, long term fasts

1989 ◽  
Vol 67 (7) ◽  
pp. 1752-1756 ◽  
Author(s):  
S. D. Pernia ◽  
D. P. Costa ◽  
C. Leo Ortiz
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Water Conservation ◽  
Urine Output ◽  
Filtration Rate ◽  
Extracellular Volume ◽  
Absolute Magnitude ◽  
Elephant Seal ◽  
Tubular Reabsorption ◽  
The Difference

Low urine output (< 200 mL/day) seen in weaned elephant seal pups is consistent with the physiological necessity of strict water conservation during periods of protracted, natural fasts. However, urine output represents only the difference between glomerular filtration rate (GFR) and tubular reabsorption and thus provides no information about the absolute magnitude of these parameters or their role in homeostatic regulation during the fast. We measured GFR, and extracellular volume (ECV) and estimated tubular reabsorption in seven pups that had been fasting > 6 weeks and in three others that had begun to feed in captivity using standard [3H]inulin and [125I]iothalamate clearance techniques. In fasting pups, GFR and ECV ranged from 78.9 to 135.2 mL/min and from 6.3 to 15.4 L, respectively. The GFR values are 59–91% [Formula: see text] of that predicted by standard body mass allometry. These data suggest that (i) low urine output is a consequence of tubular reabsorption rather than depressed GFR; (ii) a small but significant N and electrolyte load resulting from oxidation and reorganization of body tissue during development requires near "normal" renal function despite the potential loss of water from excess urine formation.

Effects of late pregnancy and early lactation on renal urea handling in Corriedale ewes

1998 ◽  
Vol 130 (2) ◽  
pp. 213-216 ◽  
Author(s):  
B. B. NDIBUALONJI ◽  
M.-N. RODRIGUEZ ◽  
D. DEHARENG ◽  
A. CIRIO ◽  
J.-M. GODEAU
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Late Pregnancy ◽  
Fractional Excretion ◽  
Urine Osmolality ◽  
Early Lactation ◽  
Plasma Urea

The aim of the study was to investigate the changes in renal function in late pregnant and early lactating Corriedale ewes. Compared with the non-productive state, plasma urea concentration was increased by 67% during pregnancy, whereas it decreased by 36% during lactation. Urine flow, urea clearance, renal plasma flow and glomerular filtration rate were significantly reduced (P<0·05) during both late pregnancy and early lactation. Filtered load of urea and the amount of urea eliminated were significantly reduced (P<0·05) only in lactating ewes. No changes were noted in the fractional excretion of urea, the filtration fraction and the urine osmolality during both late pregnancy and early lactation. It was concluded that, as in other breeds, Corriedale ewes can adapt to increased nitrogen requirements during late pregnancy, and especially during early lactation, by increasing the renal conservation of urea. Unlike other breeds, however, Corriedale ewes restrict the urine urea losses mainly by reducing renal plasma flow and glomerular filtration rate, without any modification of the tubular reabsorption of urea during both late pregnancy and early lactation.

Fluid balance, glomerular filtration rate, and urine output in dogs anesthetized for an orthopedic surgical procedure

2010 ◽  
Vol 71 (5) ◽  
pp. 501-507 ◽  
Author(s):  
Pedro Boscan ◽  
Bruno H. Pypendop ◽  
Kristine T. Siao ◽  
Thierry Francey ◽  
Kristy Dowers ◽  
...  
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Fluid Balance ◽  
Surgical Procedure ◽  
Urine Output ◽  
Filtration Rate

Effects of administration of fluids and diuretics on glomerular filtration rate, renal blood flow, and urine output in healthy awake cats

2006 ◽  
Vol 67 (4) ◽  
pp. 715-722 ◽  
Author(s):  
Jennifer M. McClellan ◽  
Richard E. Goldstein ◽  
Hollis N. Erb ◽  
Ned L. Dykes ◽  
Larry D. Cowgill
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Blood Flow ◽  
Urine Output ◽  
Filtration Rate ◽  
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