Electromagnetic Measurement of Internal Jugular Venous Flow in the Monkey

Meyer, John Stirling; Ishikawa, Susumu; Lee, T. K.

doi:10.3171/jns.1964.21.7.0524

Cited by 39 publications

(9 citation statements)

References 26 publications

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“…Electromagnetic flowmeters were placed around both internal jugular veins and CBF was measured as cerebral venous outflow. 40 The procedure for continuous monitoring of CBF is in good agreement with concurrent measurements of CBF using the nitrous oxide method, and contamination of CBF by extracerebral blood is minimal. 41 For blood gas analysis, cerebral venous blood was withdrawn from a catheter placed into the torcular Herophili via the extracorporeal system.…”

Section: Methodsmentioning

confidence: 75%

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂

Kawamura

Meyer

Hiromoto

et al. 1974

Stroke

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Abstract• Cerebral autoregulation was studied in the baboon by increasing and decreasing cerebral perfusion pressure (CPP) before and after intravenous administration (1..5 mg per kilogram) of a long-acting alpha adrenergic blocker, phenoxybenzamine (PBZ). Likewise, cerebral vasomotor reactivity to changes of arterial carbon dioxide tension (Paco 2 ) was examined before and after PBZ.In order to permit quantitative analysis, cerebral autoregulation (A.I.) and chemical vasomotor reactivity (C.I.) were expressed as indices whereACPP " ' " ""*• APaco 2 ' Following the intravenous injection of PBZ, cerebral auioregulatory vasoconstriction was impaired as CPP was increased. Cerebral vasomotor reactivity to changes in Paco 2 was altered both during hyperventilation hypocapnia (HV) and hypercarbia induced by inhalation of 5% carbon dioxide if alterations of CPP brought about by these procedures were taken into consideration. During hypocapnia C.I. was reduced 30% and during hypercarbia C.I. was increased 10%.It is concluded that PBZ reduces the vasoconstrictor tonus of cerebral vessels during hypocapnia and raised CPP. It also enhances the vasodilator response to CO, inhalation. Additional Key Words

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Section: Methodsmentioning

confidence: 75%

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂

Kawamura

Meyer

Hiromoto

et al. 1974

Stroke

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“…In the present work, the vasal action of the drugs was not evaluated; however, these drugs were used at concentrations assuring the complete presence of the vascular effect. Let us consider, for example, papaverine: increased cerebral blood flow upon intravenous or intra-arterial injection of drug was demonstrated by perfusion ex periments (13), by blood flow evaluations in the arteries afferent to and in the veins efferent from the brain (10,17,18), and by recording 85Kr clearance curves (6). The cerebral blood flow increase with papaverine is the greatest obtained with vasodilator drugs (7).…”

Section: Discussionmentioning

confidence: 99%

An Analysis of the Drugs Acting on Cerebral Energy Metabolism

Benzi

1975

Japanese Journal of Pharmacology

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Abstract-The behaviour of (a) the redox potential of the lactate/pyruvate system and the changes of the redox potential of the lactate/pyruvate system across the brain; (b) the energy charge potential of the adenylate pool, was studied in the brain of cura rized beagle dogs. The influence of certain drugs (amobarbital, nicergoline, theo phylline, papaverine, bamethan, dipyridamole, bemegride) on these parameters was evaluated under control conditions, during hypoxemia and during post-hypoxiemic recovery. On the whole, the action on energetic metabolism appears to be unrelated to the action believed to be exerted by drugs on cerebral vessels.Some of the basic problems at the cerebral level concern both the ability of drugs to interfere with energy metabolism, and the relationships between energy metabolism and blood flow. Until recently, energy metabolism and blood fluximetry were regarded as being so interdependent that a substance able to increase cerebral blood flow was always regarded as being also useful in the treatment of acute and chronic cerebropathies.Lately, this criterion has been regarded as highly questionable. The present work was planned in order to carry out a critical evaluation of the action of various drugs at the cerebral level by means of experimental methods which in our laboratory have been used for many years in the study of cerebral metabolism. Our investigations were focused on the energy charge of the adenylate pool and on the redox potential of the lactate pyru vate system under control conditions, during hypoxemia and during post-hypoxia recovery.At the same time, the action of various drugs (papaverine, theophylline, nicergoline, di pyridamole, bamethan, bemegride and amobarbital) was evaluated. MATERIALS AND METHODS Animals and anaesthesiaThe experiments were carried out on 84 male beagle dogs aged 240-360 days and weigh ing from 8.7 to 13.2 kg. Before the experiments, the dogs were maintained under the same environmental conditions (22±1°, relative humidity =60±5%) and were fed only a standard diet with water ad libitum.The surgical procedure was performed on animals pre-anaesthetized with urethane (0.4 g/kg i.p.). Electrical activity of the brain was used to determine the degree of anaes thesia (9), which was induced and maintained only during the surgical procedure by chlora lose (20-40 mg/kg i.v.). The anaesthetics affect labile phosphates and the extra and intra cellular brain lactate and pyruvate concentrations (14,21). Therefore the restoration of

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“…Continuous measurements were made of end-tidal CO 2 , systemic arterial blood pressure, intracranial venous pressure (ICVP) measured as the superior sagittal sinus wedge pressure, arterial blood gases (Po 2 , Pco 2 and cerebral venous Po 2 ) and cerebral arteriovenous oxygen difference (A-VO 2 ) in the same manner as described elsewhere. 9 ' 16 The EEG and EKG were also monitored. CBF was measured as cerebral venous outflow using electromagnetic flowmeters as described previously.…”

Section: Methodsmentioning

confidence: 99%

“…as described elsewhere, 16 depending upon the particular animal's autoregulatory and CBF/CO 2 response. In a series of pilot studies of four baboons where the Paco 2 was adjusted actually in vivo by changing the Pco 2 of the inspired air during elevation of CPP, the mean value of the correction factor was found to be 0.28 X C.I.…”

Section: Stroke Vol 7 No 3 May-june 1976mentioning

confidence: 99%

Effect of beta-adrenergic blockade with propranolol on cerebral blood flow, autoregulation and CO2 responsiveness.

Aqyagi¹,

Deshmukh²,

Meyer³

et al. 1976

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The effect of intravertebral infusion of propranolol (0.01 mg per kilogram of body weight) was compared to intravenous infusion of identical doses of propranolol so that any specific action of the drug on a possible vasomotor center in the brain stem may be assessed. Significant reductions (-25%) in CBF and CPP followed both intravertebral and intravenous infusion of propranolol. Cerebral metabolic rate for oxygen (CMRO 2 ) decreased significantly ( -18%) and cerebrovascular resistance (CVR) increased significantly ( + 19%) after intravertebral infusion of propranolol while less significant changes ensued following intravenous infusion of propranolol. Cerebral autoregulatory vasoconstriction during increases in CPP was significantly enhanced following both intravertebral and intravenous propranolol. Cerebral autoregulatory vasodilatation during decrease in CPP was not influenced by propranolol. Cerebral vasodilatory responsiveness to CO 2 inhalation was significantly inhibited following intravertebral propranolol while no significant change resulted from intravenous propranolol. Cerebral vasoconstrictive responsiveness to hyperventilation was not influenced by propranolol.These results indicate that the CBF and CMRO 2 are reduced by a pharmacological beta adrenergic blockade with propranolol hydrochloride.

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Electromagnetic Measurement of Internal Jugular Venous Flow in the Monkey

Cited by 39 publications

References 26 publications

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂

An Analysis of the Drugs Acting on Cerebral Energy Metabolism

Effect of beta-adrenergic blockade with propranolol on cerebral blood flow, autoregulation and CO2 responsiveness.

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Electromagnetic Measurement of Internal Jugular Venous Flow in the Monkey

Cited by 39 publications

References 26 publications

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO 2

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO 2

An Analysis of the Drugs Acting on Cerebral Energy Metabolism

Effect of beta-adrenergic blockade with propranolol on cerebral blood flow, autoregulation and CO2 responsiveness.

Contact Info

Product

Resources

About

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂

Neurogenic Control of Cerebral Blood Flow in the Baboon. Effects of Alpha Adrenergic Blockade With Phenoxybenzamine on Cerebral Autoregulation and Vasomotor Reactivity to Changes in Pa CO ₂