Renal and iliac vascular responses to left ventricular receptor stimulation in conscious dogs

1984 ◽  
Vol 246 (5) ◽  
pp. R788-R798
Author(s):  
A. J. Gorman ◽  
K. G. Cornish ◽  
I. H. Zucker

The purpose of the present study was to investigate the relative responses of the renal and iliac vascular beds to the selective chemical stimulation of left ventricular receptors in the conscious dog. Twenty dogs were chronically instrumented to obtain measurements of arterial blood pressure, renal blood flow, and iliac blood flow before and after a bolus intracoronary injection of veratridine (0.4-1.0 micrograms/kg in 0.5-ml vol) with the heart paced. The responses to intracoronary veratridine were a significant reduction in arterial blood pressure averaging 25 mmHg accompanied by a simultaneous reduction in renal blood flow of 25%. Renal resistance did not change throughout the course of the response analyzed (50 s). Iliac blood flow, however, increased, reaching a peak of 35% above control due to a 51% decrease in iliac resistance. After sinoaortic denervation, renal resistance still failed to show a decrease, although the recovery of arterial blood pressure and iliac resistance was prolonged. After a mild hypotensive hemorrhage (20 ml/kg), a greater decrease in iliac resistance occurred with intracoronary veratridine injections, but renal resistance still did not change. The reduction in iliac resistance with intracoronary veratridine was significantly attenuated after phentolamine administration (2 mg/kg iv) but not after atropine alone (0.2 mg/kg iv). A significant cholinergic receptor component of iliac vasodilation was observed only after prior alpha-adrenergic-receptor blockade. The results of this study are consistent with the conclusion that in the conscious dog, left ventricular receptors exert a preferential neural control over skeletal muscle vascular resistance and do not influence renal vascular resistance.

1991 ◽  
Vol 261 (1) ◽  
pp. H172-H180 ◽  
Author(s):  
L. M. Sassen ◽  
K. Bezstarosti ◽  
W. J. Van der Giessen ◽  
J. M. Lamers ◽  
P. D. Verdouw

Effects of pretreatment with L-propionylcarnitine (50 mg/kg, n = 9) or saline (n = 10) were studied in open-chest anesthetized pigs, in which ischemia was induced by decreasing left anterior descending coronary artery blood flow to 20% of baseline. After 60 min of ischemia, myocardium was reperfused for 2 h. In both groups, flow reduction abolished contractile function of the affected myocardium and caused similar decreases in ATP (by 55%) and energy charge [(ATP + 0.5ADP)/(ATP + ADP + AMP); decrease from 0.91 to 0.60], mean arterial blood pressure (by 10-24%), the maximum rate of rise in left ventricular pressure (by 26-32%), and cardiac output (by 20-30%). During reperfusion, “no-reflow” was attenuated by L-propionylcarnitine, because myocardial blood flow returned to 61 and 82% of baseline in the saline- and L-propionylcarnitine-treated animals, respectively. Cardiac output of the saline-treated animals further decreased (to 52% of baseline), and systemic vascular resistance increased from 46 +/- 3 to 61 +/- 9 mmHg.min.l-1, thereby maintaining arterial blood pressure. In L-propionylcarnitine-treated pigs, cardiac output remained at 75% of baseline, and systemic vascular resistance decreased from 42 +/- 3 to 38 +/- 4 mmHg.min.l-1. In both groups, energy charge but not the ATP level of the ischemic-reperfused myocardium tended to recover, whereas the creatine phosphate level showed significantly more recovery in saline-treated animals. We conclude that L-propionylcarnitine partially preserved vascular patency in ischemic-reperfused porcine myocardium but had no immediate effect on “myocardial stunning.” Potential markers for long-term recovery were not affected by L-propionylcarnitine.


1994 ◽  
Vol 72 (4) ◽  
pp. 394-396 ◽  
Author(s):  
Keith J. Harrington ◽  
Robert G. Allen ◽  
Jay W. Dewald

The objective of this study was to determine the dose–response effects of epinephrine, given by systemic intravenous infusion to the halothane-anesthetized newborn piglet, on renal blood flow, mean arterial blood pressure, and renal vascular resistance. Seven newborn piglets were acutely instrumented. A transit-time ultrasound flow probe was placed around the renal artery and a femoral arterial catheter was placed for blood pressure monitoring. Epinephrine was infused in doubling doses from 0.2 to 3.2 μg∙kg−1∙min−1. Mean arterial blood pressure increased from 54 mmHg (1 mmHg = 133.3 Pa) to an average of 96 mmHg at 3.2 μg∙kg−1∙min−1 of epinephrine. Renal blood flow increased from 165 mL∙min−1∙100 g−1 at baseline to 185 mL∙min−1∙100 g−1 at a dose of 0.2 μg∙kg−1∙min−1 and increased further at 0.4 and 0.8 μg∙kg−1∙min−1 to reach 261 mL∙min−1∙100 g−1. Renal blood flow began to fall at a dose of 3.2 μg∙kg−1∙min−1, remaining however, significantly above baseline (211 mL∙min−1∙100 g−1). Consequently, calculated renal vascular resistance fell as the dose was increased from 0.2 to 0.8 μg∙kg−1∙min−1 and then rose again at 1.6 and 3.2 μg∙kg−1∙min−1, being significantly above baseline at 3.2 μg∙kg−1∙min−1. These results demonstrate that epinephrine when given by systemic infusion to the halothane-anesthetized newborn pig is a renal vasodilator at low doses and causes renal vasoconstriction at moderate to high doses. Renal blood flow remained above baseline at all doses tested, and thus, within the dosage range tested, epinephrine infusion should not cause renal ischemia.Key words: epinephrine, kidney blood flow, piglet, renal vascular resistance.


1979 ◽  
Vol 46 (2) ◽  
pp. 288-292 ◽  
Author(s):  
Y. A. Mengesha ◽  
G. H. Bell

Ten to fifteen healthy subjects, ages 18--30 yr, were used to assess the correlation of forearm blood flow with graded passive body tilts and vascular resistance and also to discern the relative effects of body tilts on finger blood flow. In the head-up tilts forearm blood flow and arterial blood pressure fell progressively, whereas forearm vascular resistance and pulse rate increased. In the head-down tilts the forearm blood flow and the arterial blood pressure increased, whereas the forearm vascular resistance and pulse rate decreased. These changes were found to be significantly correlated with the different tilt angles and with one another. In a preliminary study it was found that infrared heating of the carpometacarpal region produced finger vasodilatation similar to the forearm vasodilatation observed by Crockford and Hellon (6). However, unlike forearm blood flow, finger blood flow showed no appreciable response to either the head-up or head-down tilts. This indicates that the sympathetic tone and the volume of blood in the finger are not appreciably altered by this test procedure at least 1 min after the body tilt is assumed.


1991 ◽  
Vol 81 (6) ◽  
pp. 727-732 ◽  
Author(s):  
Marohito Murakami ◽  
Hiromichi Suzuki ◽  
Atsuhiro Ichihara ◽  
Mareo Naitoh ◽  
Hidetomo Nakamoto ◽  
...  

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.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Eisei Yamamoto ◽  
Hitoshi Takano ◽  
Hiroyuki Tajima ◽  
Jun Tanabe ◽  
Hidekazu Kawanaka ◽  
...  

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.


1998 ◽  
Vol 85 (4) ◽  
pp. 1285-1291 ◽  
Author(s):  
Sandrine H. Launois ◽  
Joseph H. Abraham ◽  
J. Woodrow Weiss ◽  
Debra A. Kirby

Patients with obstructive sleep apnea experience marked cardiovascular changes with apnea termination. Based on this observation, we hypothesized that sudden sleep disruption is accompanied by a specific, patterned hemodynamic response, similar to the cardiovascular defense reaction. To test this hypothesis, we recorded mean arterial blood pressure, heart rate, iliac blood flow and vascular resistance, and renal blood flow and vascular resistance in five pigs instrumented with chronic sleep electrodes. Cardiovascular parameters were recorded during quiet wakefulness, during non-rapid-eye-movement and rapid-eye-movement sleep, and during spontaneous and induced arousals. Iliac vasodilation (iliac vascular resistance decreased by −29.6 ± 4.1% of baseline) associated with renal vasoconstriction (renal vascular resistance increased by 10.3 ± 4.0%), tachycardia (heart rate increase: +23.8 ± 3.1%), and minimal changes in mean arterial blood pressure were the most common pattern of arousal response, but other hemodynamic patterns were observed. Similar findings were obtained in rapid-eye-movement sleep and for acoustic and tactile arousals. In conclusion, spontaneous and induced arousals from sleep may be associated with simultaneous visceral vasoconstriction and hindlimb vasodilation, but the response is variable.


1991 ◽  
Vol 131 (3) ◽  
pp. 359-365 ◽  
Author(s):  
E. Cochrane ◽  
I. D. McCarthy

ABSTRACT The vascular effects of noradrenaline, ATP, parathyroid hormone (PTH) and prostaglandin E2 (PGE2) were investigated in the rat. Additionally, the exchange of mineral ions between bone and blood was assessed by measuring strontium clearance, with the aim of investigating whether the vascular effects of these agents altered uptake of mineral ions or if this exchange could be changed independently of blood flow. Radioactive microspheres and 85Sr were used to establish bone blood flow and mineral clearance. Measurements of bone blood flow and arterial pressure were made in each animal and used to calculate vascular resistance. A measurement of 85Sr clearance was also obtained. Arterial blood pressure was significantly affected by noradrenaline (P ≤ 0·003) and ATP (P ≤ 0·015). Additionally, noradrenaline significantly (P ≤ 0·03) reduced bone blood flow. This decrease was related to a significant increase in vascular resistance. Arterial blood pressure and bone blood flow were significantly reduced by both bovine PTH(1–34) (P ≤ 0·001, P ≤ 0·02) and PGE2 (P ≤ 0·005, P ≤ 0·001). Vascular resistance to bone was increased by both agents but this was only statistically significant in the case of PGE2 (P ≤ 0·01). A significant (P ≤ 0·001) reduction in strontium was also produced by PGE2. In each group the relationship between bone blood flow and strontium clearance was then analysed. Only the PGE2-treated group had a slope of the regression which was statistically different from both the control animals and the other drug-treated groups. Treatment with PGE2 therefore resulted in a dose-related decrease in 85Sr clearance which was not related to the reduction in bone blood flow. Journal of Endocrinology (1991) 131, 359–365


2019 ◽  
Vol 17 (3) ◽  
pp. 253-258
Author(s):  
P. Markova ◽  
R. Girchev

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.


2003 ◽  
Vol 95 (3) ◽  
pp. 1153-1158 ◽  
Author(s):  
H. Anetzberger ◽  
E. Thein ◽  
M. Becker ◽  
A. K. Walli ◽  
K. Messmer

In this study, we compared bone blood flow values obtained by simultaneously injected fluorescent (FM) and radiolabeled microspheres (RM) at stepwise reduced arterial blood pressure. Ten anesthetized female New Zealand White rabbits received simultaneous left ventricular injections of FM and RM at 90, 70, and 50 mmHg mean arterial blood pressure (MAP). After the experiments, both kidneys and long bones of all four limbs were removed and dissected in a standardized manner. Radioactivity (corrected for decay, background, and spillover) and fluorescence were determined, and blood flow values were calculated. Relative blood flow values estimated for each bone sample by RM and FM were significantly correlated ( r = 0.98, slope = 0.99, and intercept = 0.04 for 90 mmHg; r = 0.98, slope = 0.94, and intercept = 0.09 for 70 mmHg; r = 0.98, slope = 0.96, and intercept = 0.07 for 50 mmHg). Blood flow values (ml · min-1 · 100 g-1) of right and left bone samples determined at the different arterial blood pressures were identical. During moderate hypotension (70 mmHg MAP), blood flow in all bone samples remained unchanged compared with 90 mmHg MAP, whereas a significant decrease of bone blood flow was observed at severe hypotension (50 mmHg MAP). Our results demonstrate that the FM technique is valid for measuring bone blood flow. Differences in bone blood flow during altered hemodynamic conditions can be detected reliably. In addition, changes in bone blood flow during hypotension indicate that vasomotor control mechanisms, as well as cardiac output, play a role in setting bone blood flow.


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