Autoregulation of renal blood flow in the rat: effects of growth and uninephrectomy

1983 ◽  
Vol 244 (5) ◽  
pp. F483-F487 ◽  
Author(s):  
R. L. Chevalier ◽  
D. L. Kaiser
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Young Animal ◽  
Normal Growth ◽  
Sham Operation ◽  
Adult Rats ◽  
Arterial Blood ◽  
Relationship Of ◽  
The Relationship

As a result of normal maturation or after reduction in renal mass, renal blood flow (RBF) progressively increases. However, the effects of renal growth on the relationship of RBF to renal perfusion pressure (RPP) have not been systematically investigated. We examined RBF as a function of RPP in anesthetized young and adult rats that had been subjected to uninephrectomy or sham operation 3-4 wk previously. As a result of normal growth, mean arterial blood pressure increased from 94.1 +/- 2.7 (SE) to 118.9 +/- 4.2 mmHg. The calculated autoregulation factor, in which a value less than 1 indicates the presence of autoregulation, was 0.44 +/- 0.10 over RPP 70-100 mmHg and 1.74 +/- 0.25 over RPP 40-70 mmHg in sham-operated young animals. In adult sham-operated rats, the factor was 0.38 +/- 0.07 over RPP 100-130 mmHg and 1.03 +/- 0.07 over RPP 70-100 mmHg. Uninephrectomy in adults resulted in a 30% rise in RBF over RPP 100-130 mmHg, and there was no change in the autoregulation factor. Uninephrectomy in young rats, however, resulted in a 35% rise in RBF at RPP = 100 mmHg with only a 17% rise at RPP = 70 mmHg, and the autoregulation factor increased to 0.91 +/- 0.10 over this range of RPP. We conclude that the autoregulatory range shifts with increasing blood pressure during normal growth and that autoregulation is "reset" to higher RBF in the uninephrectomized adult rat. Although autoregulation takes place in the young animal, uninephrectomy alters the relationship of RBF to RPP such that autoregulation is impaired.

Effects of acute uninephrectomy and age on renal blood flow autoregulation in the rat

1985 ◽  
Vol 249 (5) ◽  
pp. F672-F679 ◽  
Author(s):  
R. L. Chevalier ◽  
D. L. Kaiser
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Renal Perfusion ◽  
Compensatory Hypertrophy ◽  
Hemodynamic Changes ◽  
Adult Rats ◽  
Compensatory Renal Growth ◽  
Relationship Of ◽  
The Relationship ◽  
Renal Blood Flow Autoregulation

We previously showed that renal autoregulatory behavior is modified by both normal and compensatory renal growth. To determine whether the hemodynamic changes precede an increase in renal mass, the relationship of renal blood flow (RBF) to renal perfusion pressure (RPP) was examined in the remaining kidney of anesthetized young and adult rats 30 min following contralateral nephrectomy. In young control animals 32-41 days old, an autoregulation factor (AF) of 0.37 +/- 0.10 (SE) over RPP 70-100 mmHg indicates efficient autoregulation and did not change during the experiment. Acute uninephrectomy in young hydropenic rats resulted in a 16% increase in RBF at normal RPP, and AF increased to 1.22 +/- 0.34 for RPP 70-100 mmHg, reflecting marked impairment of autoregulation. In young animals in which saline infusion was not reduced at the time of uninephrectomy, RBF increased 22% at normal RPP, and autoregulation was similarly impaired (AF 0.92 +/- 0.12 for RPP 70-100 mmHg). Acute uninephrectomy in adult rats resulted in a 13% increase in RBF, with better preservation of AF (0.48 +/- 0.09) over the adult autoregulatory range (RPP 100-130 mmHg). These findings indicate that profound hemodynamic changes take place in the remaining kidney within 30 min of acute uninephrectomy and that they are qualitatively similar to those observed after compensatory hypertrophy has developed.

Relationship of pyruvate and lactate during anaerobic metabolism. V: Coronary adequacy

1961 ◽  
Vol 200 (6) ◽  
pp. 1169-1176 ◽  
Author(s):  
William E. Huckabee
Keyword(s):  
Blood Flow ◽  
Coronary Flow ◽  
Cardiac Tissue ◽  
Anaerobic Metabolism ◽  
Constant Ratio ◽  
Blood Concentrations ◽  
Arterial Blood ◽  
Anesthetized Dogs ◽  
Relationship Of ◽  
The Relationship

Veno-arterial differences of pyruvate and lactate across the myocardium in chloralose-anesthetized dogs were very variable; in any one animal they changed continually with time despite constant blood flow and arterial blood concentrations. There was a systematic tendency of v-a lactate to vary with v-a pyruvate, as expressed in the calculated "Δ excess lactate," which remained nearly constant (or, if blood flow changed, bore a constant ratio to (a-v)O2). No change in Δ excess lactate from control values occurred in nonhypoxic experiments despite marked changes in v-a differences, arterial blood composition, and coronary flow. Cardiac Δ excess lactate became positive in most animals breathing 10% O2 in N2; output of excess lactate was also observed in all those in which moderate muscular exercise was induced. This anaerobic metabolism, or change in the relationship between pyruvate and lactate exchanges, was interpreted as an indication that O2 delivery response was not adequate to meet cardiac tissue requirements during such mild stresses when judged by the standards of adequacy of the basal state.

Effects of l-arginine on systemic and renal haemodynamics in conscious dogs

1991 ◽  
Vol 81 (6) ◽  
pp. 727-732 ◽  
Author(s):  
Marohito Murakami ◽  
Hiromichi Suzuki ◽  
Atsuhiro Ichihara ◽  
Mareo Naitoh ◽  
Hidetomo Nakamoto ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Arterial Blood Pressure ◽  
Mean Arterial Blood Pressure ◽  
Renal Haemodynamics ◽  
Conscious Dogs ◽  
Arginine Infusion ◽  
Arterial Blood

1. The effects of l-arginine on systemic and renal haemodynamics were investigated in conscious dogs. l-Arginine was administered intravenously at doses of 15 and 75 μmol min−1 kg−1 for 20 min. 2. Mean arterial blood pressure, heart rate and cardiac output were not changed significantly by l-arginine infusion. However, l-arginine infusion induced a significant elevation of renal blood flow from 50 ± 3 to 94 ± 12 ml/min (means ± sem, P < 0.01). 3. Simultaneous infusion of NG-monomethyl-l-arginine (0.5 μmol min−1 kg−1) significantly inhibited the increase in renal blood flow produced by l-arginine (15 μmol min−1 kg−1) without significant changes in mean arterial blood pressure or heart rate. 4. Pretreatment with atropine completely inhibited the l-arginine-induced increase in renal blood flow, whereas pretreatment with indomethacin attenuated it (63 ± 4 versus 82 ± 10 ml/min, P < 0.05). 5. A continuous infusion of l-arginine increased renal blood flow in the intact kidney (55 ± 3 versus 85 ± 9 ml/min, P < 0.05), but not in the contralateral denervated kidney (58 ± 3 versus 56 ± 4 ml/min, P > 0.05). 6. These results suggest that intravenously administered l-arginine produces an elevation of renal blood flow, which may be mediated by facilitation of endogenous acetylcholine-induced release of endothelium-derived relaxing factor and vasodilatory prostaglandins.

Abstract 1785: Renal Artery Angioplasty Improves Diastolic Cardiac Function In Patients With heart failure Possessing Renal Artery Stenosis.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Eisei Yamamoto ◽  
Hitoshi Takano ◽  
Hiroyuki Tajima ◽  
Jun Tanabe ◽  
Hidekazu Kawanaka ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Function ◽  
Renal Artery ◽  
Renal Blood Flow ◽  
Renal Artery Stenosis ◽  
Arterial Blood Pressure ◽  
Arterial Blood ◽  
Diastolic Cardiac Function

Background: Renal artery stenosis (RAS) often plays an important role not only in malignant hypertension but also in sudden development of heart failure (HF) so called ‘flash pulmonary edema’ or chronic HF refractory to medical treatment. One of the possible mechanisms whereby RAS affects these unique conditions of HF is suppression of LV compliance through the complex interaction between neurohormonal systems originating from the reduction of renal blood flow. Renal artery angioplasty is expected to be an effective treatment for restoring renal blood flow in patients with RAS. The aim of the present study was whether the angioplasty can improve the impaired neurohormonal systems and diastolic cardiac function in patients with RAS. Methods: A prospective analysis was performed in 18 HF patients with RAS (age: 72±6, 3 females, NYHA I/II/III: 5/9/4) who underwent renal artery angioplasty between 2005 and 2007. Four patients with significant bilateral RAS and 3 patients with unilateral RAS in the vessel supplying a functional solitary kidney were included. We monitored the changes of biochemical and neurohormonal markers and blood pressure. Cardiac function was evaluated by tissue Doppler echocardiogram before and 3 months after the procedure. Results: Technical success was achieved in all interventions. The results are shown in table . Systolic arterial blood pressure significantly decreased by renal angioplasty. B-type natriuretic peptide (BNP) was significantly reduced 3 months after the angioplasty, whereas the change of sCr or angiotensinII was not statistically significant. Myocardial early diastolic velocity (Em), a parameter of diastolic LV function, was significantly improved compared with that measured before the procedure. Conclusions: In patients with either overt or latent HF possessing RAS, renal artery angioplasty not only decreases arterial blood pressure but also improves diastolic cardiac function in parallel with the reduction of BNP level.

scholarly journals The role of l-type calcium channels in the mediation of fast oscillation of arterial blood pressure and renal blood flow in rats

2019 ◽  
Vol 17 (3) ◽  
pp. 253-258
Author(s):  
P. Markova ◽  
R. Girchev
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Arterial Blood Pressure ◽  
Experimental Period ◽  
Doppler Probe ◽  
Arterial Blood ◽  
Male Wistar Rats ◽  
Ca2 Channels

The investigation of dynamic characteristics of blood pressure and renal blood flow provides detailed information about the fast regulatory mechanisms involved in arterial blood pressure (ABP) and renal blood flow (RBF) autoregulation. The aim of our study was to investigate the role of L-type Ca2+ channels in the mediation of fast oscillations of arterial blood pressure and renal blood flow in rats by means of spectral analysis. The experiments were performed on anesthetized male Wistar rats (n=7) at the age of 12-14 weeks. The ABP was measured directly in femoral artery; RBF was registered by perivascular ultrasonic Doppler probe (Transonic system) in control and experimental period. The spectrograms from APB and RBF were derived in Lab View 3.11 software. In experimental period the selective L-type Ca2+ channel blocker amlodipine besylate (AML) in dose 200 mkg.kg-1 bolus followed by 50 mkg.kg-1.h infusions was applied. Our results by using a spectral method of analysis of ABP and RBF confirmed involvement of L-type Ca2+ channels in the mediation of dynamic nature of myogenic vascular response. The L-type Ca2+ channels in different specific manner participate in the regulation of renal blood flow and arterial blood pressure.

Sign in / Sign up

Export Citation Format

Share Document