Renal activity of vasopressin in anesthetized dogs

1961 ◽  
Vol 200 (2) ◽  
pp. 400-404 ◽  
Author(s):  
Joseph H. Perlmutt

Conventional clearance techniques were used to study the renal response to vasopressin (5–100 mu/hr.) infused for 2 1/2 hours into anesthetized (pentobarbital), surgically traumatized dogs elaborating a dilute urine. Decreased urine flow, a concomitant sustained increase in Na+ excretion, increased urine osmolality, negative free-water clearance and an increased osmolal U/P ratio (>1, <2) consistently occurred during the infusion of 50 mu/hr. Urinary pH rose and HCO3–, rather than Cl–, was the predominant anion excreted. Tubular rejection of HCO3–, however, is not essential for vasopressin activity under the conditions of this investigation since antidiuresis occurred in an acidotic dog. Usually some increase in glomerular filtration rate and effective renal plasma flow were apparent during vasopressin infusion; the former change could account for the increased Na+ excretion, but it is difficult to ascribe the peculiar anion behavior to this factor. Maximum urinary concentration was not attained even with 100 mu vasopressin/hr.

1989 ◽  
Vol 257 (3) ◽  
pp. F375-F382 ◽  
Author(s):  
T. J. Rabelink ◽  
H. A. Koomans ◽  
P. Boer ◽  
C. A. Gaillard ◽  
E. J. Dorhout Mees

Atrial natriuretic peptide (ANP) may play a role in the natriuresis after acute circulatory challenges. To assess this role in head-out water immersion (HOI), we compared in clearance studies the effect of 3 h HOI with an equally natriuretic 3-h infusion of ANP [0.01 microgram.kg-1.min-1 human ANP-(99-126)] in seven healthy individuals taking a 100 mmol sodium diet. The studies were repeated after treatment with enalapril (20 mg twice daily), which in previous studies inhibited the natriuresis after ANP. HOI caused a natriuresis equal to that of ANP infusion despite an about five times smaller rise in plasma ANP. HOI increased and ANP decreased estimated renal plasma flow (ERPF). HOI increased maximal free water clearance and decreased fractional lithium reabsorption. ANP did not affect these variables but raised minimal urine osmolality. Enalapril enhanced the fall in ERPF caused by ANP and abolished its natriuretic effect; enalapril did not impair either the natriuresis after HOI or the increase in ERPF and the fall in lithium reabsorption. These data indicate that the low dosage of ANP causes natriuresis by reducing sodium absorption in a distal nephron target segment; enalapril impairs this effect, perhaps by enhancing ANP-induced vasoconstriction, which decreases delivery to this target segment. HOI, by increasing sodium delivery to this segment, is natriuretic despite only a small rise in plasma ANP. Enalapril does not impair these effects. Although a rise in plasma ANP may be one factor in the natriuresis of HOI, the present data speak against an exclusive role. Other factors determine the magnitude of the natriuretic response.


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.


1988 ◽  
Vol 255 (6) ◽  
pp. R940-R945 ◽  
Author(s):  
M. Baerwolff ◽  
P. Bie

The possibility that small amounts of vasopressin (AVP) reduce water excretion without affecting solute excretion was investigated in conscious dogs. AVP was infused intravenously for 120 min at rates of 2 and 5 pg.min-1.kg body wt-1 during water diuresis elicited by a sustained water load of 2% body wt. During control experiments urine osmolality was constantly approximately 60 mosmol/kgH2O; during AVP infusions it increased by factors of 1.36 (P less than 0.01) and 2.12 (P less than 0.01), respectively, concomitant with 39 +/- 6 and 61 +/- 7% reductions in urine flow. Osmolar and free water clearances decreased significantly. Sodium excretion did not change; changes in potassium excretion during AVP were similar to those of the control series, i.e., a gradual decline. During AVP, 5 pg.min-1. kg-1, creatinine and urea clearances decreased (25 +/- 2 and 31 +/- 7%, respectively, both P less than 0.01). With the assumption of metabolic clearance rates of AVP of 15-40 ml.min-1.kg body wt-1, the increase in plasma AVP during the infusion of 2 pg.min-1.kg body wt-1 was 5-13 X 10(-14) M. It is concluded that small increments in plasma AVP may reduce glomerular filtration rate and that with increasing levels of AVP in plasma 1) reduction of free water clearance, 2) reduction in urea clearance, and 3) natriuresis-kaliuresis occur in that order. Apparently AVP cannot reduce water excretion without changing the rate of excretion of solutes.


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.


1997 ◽  
Vol 272 (1) ◽  
pp. R370-R376 ◽  
Author(s):  
Y. X. Wang ◽  
J. T. Crofton ◽  
L. Share

The present study was carried out to investigate whether prostaglandins (PG) are involved in the mechanism that contributes to the sex difference in the antidiuretic and pressor actions of vasopressin. The experiments were performed in conscious male and nonestrous female rats. In hydrated rats, the graded infusion of vasopressin (10-1,000 pg.min 1.kg body wt-1) resulted in a dose-dependent antidiuresis: decreases in urine flow and free water clearance and an increase in urine osmolality. These responses were significantly greater in male than in nonestrous female rats. Pretreatment with a cyclooxygenase inhibitor, indomethacin (10 mg/kg body wt iv), significantly enhanced the antidiuretic response to vasopressin in both sexes. However, the magnitude of this enhancement was greater in female than in male rats. Thus indomethacin abolished the sex difference in the antidiuretic response to vasopressin. In a separate experiment in rats without water hydration and urine collection, infusion of pressor doses of vasopressin (1,000-6,000 pg.min-1.kg body wt-1) resulted in a greater increase in blood pressure in male than in nonestrous female rats. Treatment with indomethacin enhanced this response equivalently in both sexes and thus did not affect the sex difference in the pressor action of vasopressin. These data indicate that renal PG may mediate, at least in part, the sex difference in the antidiuretic action of vasopressin, whereas vascular PG seem not to play an important role in the sex difference in the pressor action of vasopressin.


2002 ◽  
Vol 282 (4) ◽  
pp. R1149-R1155 ◽  
Author(s):  
Jens Lundbæk Andersen ◽  
Niels C. F. Sandgaard ◽  
Peter Bie

The responses to infusion of nitric oxide synthase substrate (l-arginine 3 mg · kg−1 · min−1) and to slow volume expansion (saline 35 ml/kg for 90 min) alone and in combination were investigated in separate experiments. l-Arginine left blood pressure and plasma ANG II unaffected but decreased heart rate (6 ± 2 beats/min) and urine osmolality, increased glomerular filtration rate (GFR) transiently, and caused sustained increases in sodium excretion (fourfold) and urine flow (0.2 ± 0.0 to 0.7 ± 0.1 ml/min). Volume expansion increased arterial blood pressure (102 ± 3 to 114 ± 3 mmHg), elevated GFR persistently by 24%, and enhanced sodium excretion to a peak of 251 ± 31 μmol/min, together with marked increases in urine flow, osmolar and free water clearances, whereas plasma ANG II decreased (8.1 ± 1.7 to 1.6 ± 0.3 pg/ml). Combined volume expansion and l-arginine infusion tended to increase arterial blood pressure and increased GFR by 31%, whereas peak sodium excretion was enhanced to 335 ± 23 μmol/min at plasma ANG II levels of 3.0 ± 1.1 pg/ml; urine flow and osmolar clearance were increased at constant free water clearance. In conclusion, l-arginine 1) increases sodium excretion, 2) decreases basal urine osmolality, 3) exaggerates the natriuretic response to volume expansion by an average of 50% without persistent changes in GFR, and 4) abolishes the increase in free water clearance normally occurring during volume expansion. Thus l-arginine is a natriuretic substance compatible with a role of nitric oxide in sodium homeostasis, possibly by offsetting/shifting the renal response to sodium excess.


1987 ◽  
Vol 15 (01n02) ◽  
pp. 77-82 ◽  
Author(s):  
Ho-Chan Chen ◽  
Gunilla Brattberg

Moxibustion of the Point Kuan-Yuan is said by some Chinese herb doctors to have "anti-shock" effect. Using histamine-induced shock in anesthetized dogs, we studied the cardiovascular and renal effects of moxibusting Point Kuan-Yuan. We found that it significantly increased cardiac output, total peripheral resistance, and mean blood pressure but it did not significantly increase heart rate. Moxibustion also significantly increased renal plasma flow, golmerular filtration rate, urine flow, and Na+ Cl–K+ excretions. Whether moxibusting Kuan-Yuan may be useful as an adjunct in treating clinical shocks deserves more extensive studies in well-controlled situations. It may be helpful in clinical situations in which elevation of the sympathetic activity may be beneficial.


1975 ◽  
Vol 229 (1) ◽  
pp. 222-228 ◽  
Author(s):  
EJ Braun ◽  
WH Dantzler

Effects of an acute intravenous water load on glomerular and tubular function were studied in the anesthetized desert quail Lophortyx gambelii. Total-kidney glomerular filtration rate (GFR) and single-nephron glomerular filtration rates (SNGFR) of reptilian-type and mammalian-type nephrons increased by more than 50% compared with the GFR and SNGFRs measured during a control mannitol diuresis. Despite the increase in GFR, urine flow rate was only 56% of that in control mannitol diuresis, free-water clearance (CH2o) remained at 1-2% of GFR, and the animals excreted only about 79% of the water load. More than 99% of the filtered sodium and 93% of the filtered water were reabsorbed during the water load. Possible reasons for the increased GFR and the failure to produce a dilute urine or excrete the water load are discussed.


1963 ◽  
Vol 204 (2) ◽  
pp. 197-201 ◽  
Author(s):  
Joseph H. Perlmutt

Common carotid arteries were occluded bilaterally for 5 min below the thyrocarotid arterial junctions in mildly hydrated, anesthetized dogs. Within 5–15 min after the occlusion, urine flow declined and remained below control values for 30–105 min. Concurrently, the urine became hypertonic to systemic plasma and there was no evidence for renal vasoconstriction or increased solute reabsorption. The decrement in urine flow was accounted for entirely by the decline in free-water clearance. Prolonged periods of occlusion or increased hydration altered the response. Bilateral occlusion of the common carotid arteries for 5 min above intact thyrocarotid arterial junctions (but below the carotid sinuses) or below denervated thyrocarotid arterial junctions did not affect urine flow. The time course of the response, the characteristics of the urine, and the absence of renal vasoconstriction suggest that the procedure induced a reflex release of antidiuretic hormone. Furthermore, the data indicate that the receptor area for this reflex is located in the region of the junction of the common carotid and thyroid arteries.


1977 ◽  
Vol 232 (4) ◽  
pp. F335-F340 ◽  
Author(s):  
J. D. Wallin ◽  
R. A. Kaplan

Mechanisms for the concentrating defect produced by fluoride were examined in the rat. Free-water clearance at all levels of delivery was normal after 5 days of chronic fluoride administration in the hereditary hypothalamic diabetes insipidus rat. In the Sprague-Dawley rats, during moderate fluoride administration (120 micronmol/kg per day), urine osmolality and cyclic AMP excretion decreased and urine volume increased, but after exogenous vasopressin, volume decreased and osmolality and cyclic AMP increased appropriately. During larger daily doses of fluoride (240 micronmol/kg per day) urinary osmolality and cyclic AMP decreased and volume increased, which was similar to the changes seen during lower fluoride dosages, but these parameters did not change after exogenous vasopressin. These data suggest that ascending limb chloride reabsorption is unaltered by fluoride administration; in the presence of sufficient fluoride, collecting tubular cells apparently do not generate cyclic AMP or increase permeability appropriately in response to vasopressin. The postulated defect is felt to be due to either a decrease in ATP availability or to a direct inhibitory effect of fluoride on the vasopressin-dependent cyclic AMP generating system.


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