Enoximone: oral dosing increases plasma volume and IV administration decreases renal plasma flow

InPharma ◽  
1986 ◽  
Vol 546 (1) ◽  
pp. 8-8
Keyword(s):  
Plasma Volume ◽  
Plasma Flow ◽  
Renal Plasma Flow ◽  
Oral Dosing

Glomerular filtration and renal plasma flow during hyperthermia

1960 ◽  
Vol 198 (5) ◽  
pp. 1044-1048 ◽  
Author(s):  
G. S. Kanter
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Glomerular Filtration ◽  
Plasma Volume ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Control Value ◽  
Acid Clearance ◽  
Anesthetized Dogs

The purpose of this study was to investigate the factors that determine the direction and magnitude of the alteration in GFR (glomerular filtration rate) and RPF (renal plasma flow) in hyperthermia. The investigation was conducted on anesthetized dogs. Creatinine clearance was used as a measure of GFR and para-aminohippuric acid clearance was used as a measure of RPF. The GFR in 12 mildly dehydrated dogs went from a control value of 68.4 ± 4.5 ml/min. at RT (rectal temperature) of 38.9°C to a GFR of 25.1 ± 8.5 ml/min. at a RT of 42.1°C at the end of 5 hours of exposure to heat. Final dehydration averaged –2.0% body weight. The fall in GFR and RPF was not due to dehydration for in a group of six hydrated dogs (+4% body wt. at end) similar results were obtained. No decrease in GFR or RPF occurred in either hydrated or dehydrated dogs until severe hyperthermia (> 41.2°C) was present. Though there was a decline in blood pressure towards the end of each experiment, in both groups, the decrease in GFR and RPF preceded any marked fall in pressure. Both groups showed an increase in hematocrit and a decrease in plasma volume (measured by T-1824 dilution) which became marked at the end of 5 hours of exposure to heat. The decrease in GFR and RPF appears directly related to the hyperthermia for upon rapid cooling GFR and RPF increases towards normal in spite of the persisting decreased blood pressure and plasma volume and increased hematocrit.

Glomerular ultrafiltration in the pseudopregnant rat

1982 ◽  
Vol 243 (3) ◽  
pp. F300-F305 ◽  
Author(s):  
C. Baylis
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Flow Rate ◽  
Plasma Volume ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Plasma Volume Expansion ◽  
Single Nephron ◽  
Glomerular Ultrafiltration

Whole kidney and single nephron indices of glomerular ultrafiltration were measured by clearance and micropuncture techniques in anesthetized virgin, 9-day pregnant, and 9-day pseudopregnant Munich-Wistar rats. Whole kidney glomerular filtration rate (GFR) and single nephron glomerular filtration rate (SNGFR) were elevated in pregnant and pseudopregnant rats compared with virgins (0.78 +/- 0.05, 0.75 +/- 0.06 vs. 0.57 +/- 0.03 ml/min, P less than 0.005 and P less than 0.001; 32.1 +/- 2.5, 30.0 +/- 2.8 vs. 22.1 +/- 2.0 nl/min, P less than 0.01 and P less than 0.05, respectively). Total renal plasma flow rate (RPF) and single glomerular plasma flow rate (QA) were also increased in pregnant and pseudopregnant rats compared to virgins (3.05 +/- 0.19, 2.90 +2- 0.24 vs. 2.28 +/- 0.21 ml/min, P less than 0.01 and P less than 0.05; 109.0 +/- 15.8, 100.4 +/- 12.8 vs. 68.0 +/- 6.9 nl/min, both P less thn 0.05). There was little difference in the other determinants of ultrafiltration among the three groups. Plasma volume was measured in separate experiments and was higher in pregnant and pseudopregnant rats compared with virgins (9.4 +/- 0.2, 9.8 +/- 0.4 vs. 8.4 +/- 0.3 ml, P less than 0.01 and P less than 0.05, respectively). The gestational increase in GFR in the rat occurs as the result of increased RPF, which is due to both plasma volume expansion and renal vasodilation. Since the changes in renal hemodynamics seen in pseudopregnancy were almost identical to those occurring in pregnant rats, the early stimulus to increased GFR must be maternal and not fetoplacental in origin.

VERLAUFSUNTERSUCHUNGEN DES WASSERHAUSHALTES BEI ADIPÖSEN UNTER TRIJODTHYRONINTHERAPIE MIT BERÜCKSICHTIGUNG DER ALDOSTERONAUSSCHEIDUNG IM HARN UND EINES ANTIDIURETISCHEN PRINZIPS IM SERUM (ADH)

1961 ◽  
Vol 37 (1) ◽  
pp. 85-95 ◽  
Author(s):  
J. M. Olsen ◽  
H. W. Bansi ◽  
K. J. Olsen ◽  
F. Fretwurst
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Plasma Volume ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Extracellular Fluid ◽  
Sodium Potassium ◽  
Fluid Compartments ◽  
The One

ABSTRACT In 4 patients with excessive obesity (78.4—160.8 kg body-weight) the following determinations were performed before and during triiodo-thyronine treatment: the aldosterone excretion in the urine, the serum concentration of antidiuretic substances (ADH according to Buchborn), the osmolality, sodium, potassium and chloride in plasma and urine, the total and extracellular fluid compartments, the glomerular filtration rate (by inulin clearance), the renal plasma flow, and the circulating plasma volume. During triiodothyronine treatment, the previously increased levels of aldosterone in the urine and the serum ADH decreased towards the normal range. The glomerular filtration rate and the renal plasma flow, both as a rule significantly reduced in obesity, as well as the circulating plasma volume were increased. In all 4 cases, the administration of triiodo-thyronine was followed by distinct natriuresis, reduction of the cholesterol level in the serum, and an increase of the basal metabolic rate. A statistically significant relation could be demonstrated between the aldosterone excretion rate in the urine and the ADH concentration of the serum on the one hand and the circulating plasma volume on the other. This relation was also found between the aldosterone excretion and ADH concentration in the serum.

Glomerular ultrafiltration dynamics: euvolemic and plasma volume-expanded rats

1980 ◽  
Vol 239 (2) ◽  
pp. F171-F186 ◽  
Author(s):  
W. J. Arendshorst ◽  
C. W. Gottschalk
Keyword(s):  
Glomerular Filtration ◽  
Plasma Volume ◽  
Plasma Flow ◽  
Renal Plasma Flow ◽  
Plasma Volume Expansion ◽  
Filtration Pressure ◽  
Chapel Hill ◽  
Single Nephron ◽  
Glomerular Ultrafiltration ◽  
Ultrafiltration Pressure

With the use of micropuncture techniques, glomerular dynamics were characterized in euvolemic Munich-Wistar (Chapel Hil) rats. Single nephron glomerular filtration rate (SNGFR) and plasma flow (SNGPF) averaged 31 nl/min and 100 nl/min, respectively. Efferent effective ultrafiltration pressure (PUF) was greater than zero in each animal (7 mmHg, P less than 0.001), indicating filtration pressure disequilibrium. Mean PUF (PUF) was 15 mmHg and specific glomerular filtration coefficient (Kf) values averaged 0.033 nl/(s x mmHg). Similar experiments were performed on Munich-Wistar rats from B.M. Brenner's colony. Filtration pressure equilibrium was reached in rats with SNGPF < 112 nl/min; disequilibrium existed when SNGPF was > 168 nl/min. Overall, PUF (15 mmHg) was similar to that in Chapel Hill rats, SNGFR (49 nl/min) was greater, as was specific Kf (0.066 nl/(s.mmHg)). These observations document important Kf differences in the two colonies. In other experiments on Chapel Hill rats, plasma volume expansion produced increases in SNGPF and renal plasma flow (RPF). However, SNGFR (33 nl/min) and GFR (1.2 ml/(min x g kidney wt)) were unchanged, as were SNGFR/GFR and SNGPF/RPF ratios. SNGFR was relatively insensitive to increased plasma flow because of the relatively low Kf and filtration pressure disequilibrium during euvolemia. In additional experiments, GFR was also only weakly dependent on RPF in conscious rats.

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.

RENAL FUNCTION AND KIDNEY SIZE FOLLOWING HYPOPHYSECTOMY IN MAN

1965 ◽  
Vol 48 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Thomas Falkheden ◽  
Ingmar Wickbom
Keyword(s):  
Renal Function ◽  
Diabetic Retinopathy ◽  
Glomerular Filtration Rate ◽  
Plasma Flow ◽  
Mammary Carcinoma ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Kidney Weight ◽  
Kidney Size ◽  
Before And After

ABSTRACT Measurements of glomerular filtration rate (GFR) and renal plasma flow (RPF) were performed in close connection with roentgenographic estimation of kidney size, before and after hypophysectomy, in 10 patients (four cases of metastatic mammary carcinoma, five cases of diabetic retinopathy and one case of acromegaly). Hypophysectomy was regularly followed by a decrease in GFR and RPF. In most cases, a reduction in the roentgenographic kidney size was also observed. However, the changes in the roentgenographic kidney size and calculated kidney weight after hypophysectomy were smaller and occurred at a slower rate than the alterations in GFR and RPF. The results favour the view that, primarily, the decrease in GFR and RPF following hypophysectomy is essentially functional rather than due to a reduced kidney mass.

Influence of nifedipine on cyclosporin A nephrotoxicity after unilateral nephrectomy in the spontaneously hypertensive rat

1991 ◽  
Vol 81 (2) ◽  
pp. 271-279 ◽  
Author(s):  
P. G. McNally ◽  
F. Baker ◽  
N. Mistry ◽  
J. Walls ◽  
J. Feehally
Keyword(s):  
Body Weight ◽  
Glomerular Filtration Rate ◽  
Renal Impairment ◽  
Cyclosporin A ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Denervation ◽  
Renal Plasma Flow ◽  
Spontaneously Hypertensive

1. Nifedipine ameliorates cyclosporin A-induced renal impairment in surgically intact (two-kidney) rats. This study investigates the effect of nifedipine on cyclosporin A nephrotoxicity in spontaneously hypertensive rats after either uninephrectomy or uninephrectomy with contralateral renal denervation. 2. Fourteen days after uninephrectomy pair-fed rats were injected for 14 days with cyclosporin A (25 mg/kg body weight) via the subcutaneous route and with nifedipine (0.1 mg/kg body weight) via the intraperitoneal route. Renal and systemic haemodynamics were measured in conscious unrestrained rats. 3. Whole-blood levels of cyclosporin A did not differ between groups (overall 352 ± 22 ng/ml, means ± sem). After uninephrectomy, cyclosporin A decreased the glomerular filtration rate (olive oil versus cyclosporin A: 0.96 ± 0.04 versus 0.70 ± 0.06 ml min−1 100 g body weight, P < 0.02) and effective renal plasma flow (1.94 ± 0.10 versus 1.38 ± 0.13, P < 0.01), and increased renal vascular resistance {(20.2 ± 1.8) × 104 versus (31.6 ± 3.3) × 104 kPa l−1 s [(20.2 ± 1.8) × 103 versus (31.6 ± 3.3) × 103 dyn s cm−5], P < 0.02} and mean arterial pressure (146.7 ± 6.7 versus 167.3 ± 2.9 mmHg, P < 0.05). Neither renal denervation nor nifedipine prevented the reduction in glomerular filtration rate or effective renal plasma flow induced by cyclosporin A. 4. This study infers that the sympathetic nervous system does not play an active role in cyclosporin A nephrotoxicity and demonstrates that the concomitant administration of nifedipine to rats with reduced renal mass does not ameliorate cyclosporin A-induced renal impairment.

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