Continuous measurement of renal cortical blood flow and renal arterial blood flow during stimulation of the renal nerve

1991 ◽  
Vol 29 (2) ◽  
pp. 121-128 ◽  
Author(s):  
F. A. Speiman ◽  
P. -A. Öberg
Keyword(s):  
Blood Flow ◽  
Continuous Measurement ◽  
Arterial Blood Flow ◽  
Renal Nerve ◽  
Cortical Blood Flow ◽  
Arterial Blood ◽  
Renal Cortical Blood Flow ◽  
Stimulation Of

scholarly journals Selective Electrical Stimulation of Postganglionic Cerebrovascular Parasympathetic Nerve Fibers Originating from the Sphenopalatine Ganglion Enhances Cortical Blood Flow in the Rat

1990 ◽  
Vol 10 (3) ◽  
pp. 383-391 ◽  
Author(s):  
Norihiro Suzuki ◽  
Jan Erik Hardebo ◽  
Jan Kåhrström ◽  
Christer Owman
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Nerve Fibers ◽  
Microvascular Blood Flow ◽  
Sphenopalatine Ganglion ◽  
Flow Measurements ◽  
Parasympathetic Nerve ◽  
Cortical Blood Flow ◽  
Arterial Blood ◽  
Stimulation Of

Recently, the origins and pathways of cerebrovascular acetylcholine- and vasoactive intestinal polypeptide-containing nerves have been elucidated in detail in the rat: The sphenopalatine ganglion is the major source for postganglionic parasympathetic fibers to the vascular beds of the cerebral hemispheres. To clarify the functional role of the nerves on cerebral blood vessels in vivo, brain cortical microvascular blood flow was measured in rats during electrical stimulation of these particular postganglionic fibers. Animals were subjected to transection of the right nasociliary nerve 2 weeks before the flow measurements to eliminate activation of peptidergic sensory fibers. Relative change in microvascular blood flow was continuously recorded by a laser-Doppler flowmeter system under α-chloralose anesthesia. The postganglionic fibers were electrically stimulated just proximal to the ethmoidal foramen by a bipolar platinum electrode (5 V; 0.5 ms; 3, 10, 30, 60 Hz; as a continuous stimulation for 90 s). Stimulation at 10 Hz induced a marked increase of the cortical blood flow (CoBF) on the ipsilateral side, whereas no change was observed on the contralateral side. It reached a maximum mean value of 42.5% at 46 s, and then slightly declined during the remaining stimulation period. No significant changes were observed in the mean arterial blood pressure or blood gases during or after stimulation. Both atropine and scopolamine failed to alter this flow increase. Electrical stimulation of the postganglionic fibers at different frequencies revealed a maximal increase in the CoBF at 30 Hz in the control situation (47.2%), but at 10 Hz after scopolamine administration (51.6%). This provides the first report showing that selective postganglionic stimulation of the parasympathetic nerve fibers markedly enhances blood flow in the brain, and it supports the view that the neurogenic vasodilatation is primarily noncholinergic.

Abstract 266: Renovascular Remodeling in Hypertensive Dahl-SS Rats: Role of MMP Inhibitor as a Hypertension Ameliorating Agent

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Sourav Kundu ◽  
Sathnur Pushpakumar ◽  
Naira Metriveli ◽  
Suresh C Tyagi ◽  
Utpal Sen
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Vascular Density ◽  
High Salt Diet ◽  
Doppler Flowmetry ◽  
Cortical Blood Flow ◽  
Mmp Inhibitor ◽  
Arterial Blood ◽  
Renal Cortical Blood Flow ◽  
Renal Vascular

High salt diet has long been associated with chronic hypertension. The development of renal injury in Dahl salt-sensitive (SS) hypertensive rats is characterized by structural and functional changes involving vascular remodeling. Increased activity of matrix metalloproteinases (MMPs) leading to alteration in the extracellular matrix (ECM) is the main mechanism contributing to increased peripheral vascular resistance. In this study, we hypothesized that inhibition of MMPs will modulate ECM remodeling by decreasing MMP activity and thus reduce mean arterial blood pressure. METHODS: We used Dahl-salt sensitive (Dahl-SS) and Lewis rats fed on high salt diet. The groups were 1) Dahl-SS, 2) Dahl-SS+GM6001 (non-specific MMP inhibitor), 3) Lewis, and 4) Lewis+GM6001. GM6001 was given at 0.5mg/mL by intra-peritoneal injection on alternate days for 3 weeks. Blood pressure, laser doppler flowmetry for renal cortical blood flow and barium angiography for renal vascular density were measured. Results: Mean arterial blood pressure was 172.10 ± 0.57 mm Hg in hypertensive Dahl-SS rats compared to 136.12 ± 1.22 mm Hg in Dahl-SS+GM6001 rats. The mean arterial pressures in lewis and lewis+GM6001 groups were 97.08 ± 0.56 and 87.63 ± 2.93 mm Hg respectively. Laser doppler flowmetry showed reduced renal cortical blood flow (1333.33 flux units) in Dahl-SS rats compared to Dahl-SS rats treated with GM6001 (1605 flux units). Lewis rats showed similar renal cortical flow with (1488.33 flux units) or without GM6001 (1425 flux units). Barium angiography demonstrated increased renal vascular density with patent branches in the renal cortex of animals treated with MMP inhibitor, GM6001. Conclusion: Our results suggest that in hypertensive Dahl-SS rats, inhibition of MMP attenuates high blood pressure, maintains patency of renal cortical vessels thus improving cortical blood flow.

Continuous measurement of renal blood flow changes to renal nerve stimulation and intra-arterial drug administration in the rat

1978 ◽  
Vol 234 (2) ◽  
pp. H219-H222 ◽  
Author(s):  
G. D. Fink ◽  
M. J. Brody
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Renal Artery ◽  
Nerve Stimulation ◽  
Continuous Measurement ◽  
Renal Nerve ◽  
Renal Nerve Stimulation ◽  
Renal Vascular ◽  
Flow Circuit ◽  
Stimulation Of

A method is described for continuous measurement of renal blood flow in the anesthetized rat without dissection of the renal artery. Blood flow and arterial pressure were measured in an extracorporeal flow circuit between the carotid artery and an aortic pouch from which the left renal artery was the only outlet. Injection into the flow circuit allowed delivery of drugs directly into the arterial blood supply of the kidney. Electrical stimulation of undamaged periarterial renal kidney. Electrical stimulation of undamaged periarterial renal nerves was possible since the renal artery remained undisturbed. Extracorporeal autoperfusion of the rat kidney produced renal flow and resistance measurements that did not differ from those obtained with a flow probe placed directly on the renal artery. Renal nerve stimulation was found to cause renal vasoconstriction due to activation of alpha-adrenergic receptors by norepinephrine released from postganglionic sympathetic neurons. Renal vascular responses to a variety of intra-arterial vasoactive agents were also determined. The method described here allows the evaluation of renal vascular control in the variety of disease states for which suitable rat models have been developed.

Arterial Blood Flow and Microcirculatory Changes in the Rat Groin Flap after Ischemia Provocation by Electrical Stimulation of the Artery

2001 ◽  
Vol 62 (3) ◽  
pp. 243-251 ◽  
Author(s):  
Y. Qi ◽  
B. Gazelius ◽  
B. Linderoth ◽  
O. Löfgren ◽  
O. Gribbe ◽  
...  
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Arterial Blood Flow ◽  
Groin Flap ◽  
Arterial Blood ◽  
Stimulation Of

Modeling Elastic Walls in Lattice Boltzmann Simulations of Arterial Blood Flow

2013 ◽  
Vol 23 (2) ◽  
Author(s):  
Xenia Descovich ◽  
Giuseppe Pontrelli ◽  
Sauro Succi ◽  
Simone Melchionna ◽  
Manfred Bammer
Keyword(s):  
Blood Flow ◽  
Lattice Boltzmann ◽  
Arterial Blood Flow ◽  
Arterial Blood ◽  
Lattice Boltzmann Simulations ◽  
Elastic Walls

scholarly journals Sustained Inflation Reduces Pulmonary Blood Flow during Resuscitation with an Intact Cord

Children ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 353
Author(s):  
Jayasree Nair ◽  
Lauren Davidson ◽  
Sylvia Gugino ◽  
Carmon Koenigsknecht ◽  
Justin Helman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Perinatal Asphyxia ◽  
Arterial Blood Flow ◽  
Positive Pressure ◽  
Optimal Timing ◽  
Delayed Cord Clamping ◽  
Arterial Blood ◽  
Cord Clamping ◽  
Sustained Inflation ◽  
Near Term

The optimal timing of cord clamping in asphyxia is not known. Our aims were to determine the effect of ventilation (sustained inflation–SI vs. positive pressure ventilation–V) with early (ECC) or delayed cord clamping (DCC) in asphyxiated near-term lambs. We hypothesized that SI with DCC improves gas exchange and hemodynamics in near-term lambs with asphyxial bradycardia. A total of 28 lambs were asphyxiated to a mean blood pressure of 22 mmHg. Lambs were randomized based on the timing of cord clamping (ECC—immediate, DCC—60 s) and mode of initial ventilation into five groups: ECC + V, ECC + SI, DCC, DCC + V and DCC + SI. The magnitude of placental transfusion was assessed using biotinylated RBC. Though an asphyxial bradycardia model, 2–3 lambs in each group were arrested. There was no difference in primary outcomes, the time to reach baseline carotid blood flow (CBF), HR ≥ 100 bpm or MBP ≥ 40 mmHg. SI reduced pulmonary (PBF) and umbilical venous (UV) blood flow without affecting CBF or umbilical arterial blood flow. A significant reduction in PBF with SI persisted for a few minutes after birth. In our model of perinatal asphyxia, an initial SI breath increased airway pressure, and reduced PBF and UV return with an intact cord. Further clinical studies evaluating the timing of cord clamping and ventilation strategy in asphyxiated infants are warranted.

Sign in / Sign up

Export Citation Format

Share Document