Spinal cord blood flow as affected by changes in systemic arterial blood pressure

1976 ◽  
Vol 44 (1) ◽  
pp. 12-15 ◽  
Author(s):  
Arthur I. Kobrine ◽  
Thomas F. Doyle ◽  
Hugo V. Rizzoli
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cord Blood ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Arterial Blood ◽  
Wide Range ◽  
Blood Pressures ◽  
Infusion Of Norepinephrine ◽  
Hydrogen Clearance

✓ The authors used the hydrogen clearance method to measure focal spinal cord blood flow (SCBF) in the rhesus monkey over a wide range of mean arterial blood pressures (MAP) in an attempt to test the hypothesis of autoregulation. The MAP was either lowered by bleeding or raised by the intravenous infusion of norepinephrine or angiotensin. The SCBF remained constant and in the normal range with an MAP of 50 to 135 mm Hg, indicating the presence of autoregulation. Below 50 mm Hg, SCBF fell passively with further decreases in MAP. At MAP values above 135 mm Hg, vasodilatation occurred which resulted in a breakthrough of autoregulation and marked increases in SCBF with further increases in the MAP.

The effects of beta adrenergic blockade on spinal cord autoregulation in the monkey

1977 ◽  
Vol 47 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Arthur I. Kobrine ◽  
Delbert E. Evans ◽  
Hugo V. Rizzoli
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cord Blood ◽  
Adrenergic Blockade ◽  
Spinal Cord Blood Flow ◽  
Beta Adrenergic ◽  
Content Type ◽  
Arterial Blood ◽  
Wide Range ◽  
Adrenergic Blocker

✓ Blood flow in the spinal cord was measured in a group of monkeys over a wide range of artificially varied blood pressures after the administration of propranolol, a beta adrenergic blocker. Spinal cord blood flow was found to be constant and in the normal range between a mean system arterial blood pressure of 50 to 150 mm Hg. From 150 to 180 mm Hg spinal cord blood flow decreased. There was no breakthrough of autoregulation, previously seen in the untreated animal. It is suggested, therefore, that the previously observed breakthrough of autoregulation is a beta adrenergic-mediated phenomenon.

The effect of alpha adrenergic blockade on spinal cord autoregulation in the monkey

1977 ◽  
Vol 46 (3) ◽  
pp. 336-341 ◽  
Author(s):  
Arthur I. Kobrine ◽  
Delbert E. Evans ◽  
Hugo V. Rizzoli
Keyword(s):  
Spinal Cord ◽  
Dominant Role ◽  
Adrenergic Blockade ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Alpha Adrenergic Receptors ◽  
Arterial Blood ◽  
Wide Range ◽  
Blood Pressures

✓ Spinal cord blood flow (SCBF) was measured over a wide range of artificially varied mean systemic arterial blood pressures (MAP) in a group of monkeys with alpha adrenergic receptors blocked by the intravenous administration of phenoxybenzamine (Dibenzyline). The SCBF was found to vary linearly with changes in MAP. Autoregulation appeared to have been abolished. These data are cited as evidence for a dominant role of the sympathetic nervous system in control of the spinal circulation.

The effect of hypothermia on regional spinal cord blood flow in rats

1989 ◽  
Vol 70 (5) ◽  
pp. 780-784 ◽  
Author(s):  
Toshihisa Sakamoto ◽  
William W. Monafo
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cord Blood ◽  
Spinal Cord Ischemia ◽  
Control Level ◽  
Normal Group ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Arterial Blood ◽  
Anesthetized Rats

✓ Spinal cord ischemia may accompany surgical procedures on the aorta or vertebral column. Regional spinal cord blood flow (SCBF) was measured at five vertebral levels in the spinal cords of pentobarbital-anesthetized rats based on the distribution of intravenously injected carbon-14-labeled butanol. In seven normal rats, mean SCBF (± standard error of the mean) ranged from 52.7 ± 5.4 to 68.5 ± 4.9 ml ⋅ min−1 ⋅ 100 gm−1 (depending on the level, being lowest at the thoracic levels) and mean arterial blood pressure (MABP) was 126 mm Hg. Corporal hypothermia (mean rectal temperature 28.1° ± 0.6°C) was induced by cold exposure in seven other rats, and SCBF, measured immediately thereafter, was significantly elevated at all five levels by 52% to 69% compared to the normal group. However, MABP was elevated in the hypothermic group to 165 ± 4 mm Hg (p < 0.0001). Therefore, in seven additional hypothermic rats, MABP was maintained at the control level by withdrawal of arterial blood as necessary. In these animals, SCBF at all levels was still significantly elevated compared with the normal group and the values were nearly identical to those measured in the hypertensive hypothermic rats. It was concluded that hemodynamic autoregulation of SCBF is impaired in the presence of moderate systemic hypothermia in pentobarbital-anesthetized rats.

Regional spinal cord blood flow in primates

1976 ◽  
Vol 45 (6) ◽  
pp. 647-659 ◽  
Author(s):  
Alan N. Sandler ◽  
Charles H. Tator
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cord Blood ◽  
Gray Matter ◽  
Mean Value ◽  
Spinal Cord Blood Flow ◽  
Thoracic Spinal Cord ◽  
Content Type ◽  
Arterial Blood ◽  
Thoracic Spinal

✓ Spinal cord blood flow (SCBF) was measured in the primate thoracic spinal cord using the 14C-antipyrine autoradiographic technique that allowed clear differentiation between white and gray matter blood flow. Individual SCBF values were obtained for 0.1-sq mm areas of the thoracic cord cross section. White matter blood flow was homogeneous throughout with a mean value of 10.3 ± 0.2 ml/100 gm/min. Graymatter flow was more variable with lower values in the dorsal horns and higher values in the central gray and anterior horns. Mean gray-matter flow was 57.6 ± 2.3 ml/100 gm/min. Arterial pO2 was 123 ± 2 torr, pCO2 was 40.2 ± 0.5 torr and pH was 7.327 ± 0.010. Mean arterial blood pressure was 113 ± 3 mm Hg and core temperature was 36.4° ± 0.1° C.

Comparison of hydrogen clearance and 14C-antipyrine autoradiography in the measurement of spinal cord blood flow after severe impact injury

1980 ◽  
Vol 52 (6) ◽  
pp. 801-807 ◽  
Author(s):  
David F. Cawthon ◽  
Howard J. Senter ◽  
William B. Stewart
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Flow Patterns ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Thoracic Cord ◽  
Impact Injury ◽  
Hydrogen Clearance

✓ Spinal cord blood flow was measured by two different techniques in normal and traumatized cat spinal cord. Flow was measured in the thoracic cord after severe (500 gm-cm) impact injury at T-6. Blood flow was measured sequentially at two sites for 7 hours after trauma using the hydrogen clearance technique, and spatially at many sites but at selected times by means of the 14C-antipyrine autoradiographic method. The two techniques gave similar results. Control white-matter blood flow in the lateral funiculus was 11.13 ± 1.29 ml/min/100 gm in the hydrogen clearance series, and 11.07 ± 3.16 gm blood/min/100 gmin the antipyrine series. Following injury, blood flow remained in the control range until 1 hour after trauma, when ischemia became the major pattern. From 4 to 8 hours following trauma, several categories of flow patterns emerged. In one group of animals, white-matter blood flow returned to control levels at some points along the length of cord surveyed, but remained depressed at adjacent cord levels. In another category of animals, most sites in the white matter had flows approaching control levels by 7 to 8 hours. In yet another group, all sites examined, although a limited number, showed ischemia. In contrast, gray-matter ischemia appeared earlier (25% of control levels at 1 hour), had a sharper focus, and persisted in the period examined. The differences in blood flow between gray and white matter and the longitudinal variation in white-matter flow suggested that the hydrogen clearance method should be verified by autoradiography for accuracy of spatial flow patterns.

Effects of laminectomy on spinal cord blood flow

1978 ◽  
Vol 48 (2) ◽  
pp. 232-238 ◽  
Author(s):  
Douglas K. Anderson ◽  
Gregory R. Nicolosi ◽  
Eugene D. Means ◽  
L. Edward Hartley
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cord Blood ◽  
Reference Sample ◽  
Significant Decline ◽  
Entire Length ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Sample Method ◽  
Fine Print

✓ The effect of a one-segment (L-2) laminectomy on spinal cord blood flow (SCBF) was determined by the reference sample method using isotope-labeled microspheres. The SCBF was measured before laminectomy (control) and at 15 minutes postlaminectomy with the dura exposed (Series 1), 1 hour postlaminectomy with the laminectomy site closed (Series 2), 24 hours postlaminectomy with the laminectomy site closed (Series 3), and 24 hours postlaminectomy with the dura exposed (Series 4). With the laminectomy site open, SCBF was significantly depressed (22% to 45%) along the entire length of the spinal cord at 15 minutes postlaminectomy. At 1 hour postlaminectomy (with the laminectomy site closed), SCBF approached control values, although areas with significantly lowered flow were still observed in all portions of the spinal cord. By 24 hours postlaminectomy, SCBF had returned to prelaminectomy levels. However, if within 1 hour preceding the 24-hour SCBF measurement, the laminectomy site was reopened, SCBF tended to fall at and caudad to the laminectomy site. These data indicate that laminectomy can cause a significant decline in SCBF. At the present time, the mechanism(s) for this laminectomy-induced depression of SCBF are unknown, although a temperature-induced vasoconstriction is suspected.

scholarly journals Blood supply and vascular reactivity of the spinal cord under normal and pathological conditions

2011 ◽  
Vol 15 (3) ◽  
pp. 238-251 ◽  
Author(s):  
Nikolay L. Martirosyan ◽  
Jeanne S. Feuerstein ◽  
Nicholas Theodore ◽  
Daniel D. Cavalcanti ◽  
Robert F. Spetzler ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cord Blood ◽  
Blood Supply ◽  
Vascular Reactivity ◽  
Vascular System ◽  
Spinal Cord Blood Flow ◽  
Arterial Blood ◽  
Severity Of Injury ◽  
Cord Injury

The authors present a review of spinal cord blood supply, discussing the anatomy of the vascular system and physiological aspects of blood flow regulation in normal and injured spinal cords. Unique anatomical functional properties of vessels and blood supply determine the susceptibility of the spinal cord to damage, especially ischemia. Spinal cord injury (SCI), for example, complicating thoracoabdominal aortic aneurysm repair is associated with ischemic trauma. The rate of this devastating complication has been decreased significantly by instituting physiological methods of protection. Traumatic SCI causes complex changes in spinal cord blood flow, which are closely related to the severity of injury. Manipulating physiological parameters such as mean arterial blood pressure and intrathecal pressure may be beneficial for patients with an SCI. Studying the physiopathological processes of the spinal cord under vascular compromise remains challenging because of its central role in almost all of the body's hemodynamic and neurofunctional processes.

Effect of aminophylline and isoproterenol on spinal cord blood flow after impact injury

1980 ◽  
Vol 53 (3) ◽  
pp. 385-390 ◽  
Author(s):  
Diana Dow-Edwards ◽  
Vincent DeCrescito ◽  
John J. Tomasula ◽  
Eugene S. Flamm
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
White Matter ◽  
Cord Blood ◽  
Gray Matter ◽  
Adenosine Monophosphate ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Cord Injury ◽  
Matter Flow

✓ A study of the effects of spinal cord injury upon spinal cord blood flow was carried out in cats. A 400 gm-cm impact produced an overall reduction in spinal cord blood flow of 24% in the white matter and 30% in the gray matter, as determined by 14C-antipyrine autoradiography. At the level of the injury, white-matter flow was 8.1 ml/100 gm/min, a reduction of 49%, and in the gray matter, 12.5 ml/100 gm/min, a reduction of 76%. Treatment with aminophylline and isoproterenol improved the overall blood flow in the spinal cord. At the level of the injury, white-matter flow after this treatment was no longer significantly different from control values. The gray-matter flow remained decreased to 26.2 ml/100 gm/min, a reduction of only 47%. It is proposed that aminophylline and isoproterenol may increase cyclic adenosine monophosphate (AMP) and prevent platelet aggregation along the endothelial surfaces of the microcirculation, and may thereby help to maintain improved perfusion of the injured spinal cord.

Antinociceptive and Hemodynamic Effects of a Novel α2-Adrenergic Agonist, MPV-2426, in Sheep 

1999 ◽  
Vol 91 (5) ◽  
pp. 1425-1425 ◽  
Author(s):  
James C. Eisenach ◽  
Patricia Lavand'homme ◽  
Chuanyao Tong ◽  
Jen-Kun Cheng ◽  
Hui-Lin Pan ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cerebrospinal Fluid ◽  
Cord Blood ◽  
Intrathecal Injection ◽  
Adrenergic Agonists ◽  
Hemodynamic Effects ◽  
Adrenergic Agonist ◽  
Spinal Cord Blood Flow ◽  
Arterial Blood

Background alpha2-Adrenergic agonists produce analgesia primarily by a spinal action and hypotension and bradycardia by actions at several sites. Clonidine is approved for epidural use in the treatment of neuropathic pain, but its wider application is limited by hemodynamic side effects. This study determined the antinociceptive and hemodynamic effects of a novel alpha2-adrenergic agonist, MPV-2426, in sheep. Methods Forty sheep of mixed Western breeds with indwelling catheters were studied. In separate studies, antinociception to a mechanical stimulus, hemodynamic effects, arterial blood gas tensions, cerebrospinal fluid pharmacokinetics, and spinal cord blood flow was determined after epidural, intrathecal, and intravenous injection of MPV-2426. Results MPV-2426 produced antinociception with greater potency intrathecally (ED50 = 49 microg) than epidurally (ED50 = 202 microg), whereas intravenous administration had no effect. Intrathecal injection, in doses up to three times the ED95, failed to decrease systemic or central arterial blood pressures or heart rate, whereas larger doses, regardless of route, increased systemic arterial pressure. Bioavailability in cerebrospinal fluid was 7% after epidural administration and 0.17% after intravenous administration. Intrathecal MPV-2426, in an ED95 dose and three times this dose, produced a dose-independent reduction in thoracic and lumbar spinal cord blood flow. Conclusions MPV-2426 shares many characteristics of other alpha2-adrenergic agonists examined in sheep, but differs from clonidine and dexmedetomidine by lack of antinociception and minimal reduction in oxygen partial pressure after large intravenous and epidural injections. No hemodynamic depression was observed after intrathecal injection at antinociceptive doses. These results suggest this compound may be an effective spinal analgesic in humans with less hypotension than clonidine, although its relative potency to cause sedation was not tested in this study.

Regional spinal cord blood flow in rats after severe cord trauma

1978 ◽  
Vol 49 (6) ◽  
pp. 844-853 ◽  
Author(s):  
Alex S. Rivlin ◽  
Charles H. Tator
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cord Blood ◽  
Gray Matter ◽  
Albino Rats ◽  
Compression Injury ◽  
Spinal Cord Blood Flow ◽  
Compression Technique ◽  
Content Type ◽  
Cord Injury

✓ Spinal cord blood flow (SCBF) was measured in 12 albino rats following acute cord injury produced by the extradural clip compression technique. Severe injury was produced with the clip compressing the cord with a force of 180 gm for 5 minutes, an injury previously shown to produce a severe functional deficit. Regional SCBF was measured 15 minutes, 2 hours, and 24 hours after injury by the 14C-antipyrine autoradiographic technique and a scanning microscope photometer. At 15 minutes and 2 hours, white and gray matter blood flow was severely diminished, and, at 24 hours, there was only minimal improvement. Focal decreases in blood flow were seen in white and gray matter for a considerable distance proximal and distal to the site of cord trauma. Thus, it has been confirmed in this model that severe cord compression injury produces severe posttraumatic ischemia in the cord which lasts for at least 24 hours.

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