scholarly journals Perivascular Microapplication of Endothelin-1: A New Model of Focal Cerebral Ischaemia in the Rat

1993 ◽  
Vol 13 (5) ◽  
pp. 865-871 ◽  
Author(s):  
John Sharkey
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Ischaemia ◽  
Dorsal Hippocampus ◽  
Focal Cerebral Ischaemia ◽  
Local Cerebral Blood Flow ◽  
Guide Cannula ◽  
Conscious Rat ◽  
Endothelin 1 ◽  
Arterial Blood

In the present study, we describe the effects of perivascular microapplication of the potent vasoconstrictor peptide endothelin-1 (Et-1; (120 pmol in 3 μl), delivered via a guide cannula stereotaxically positioned above the left cerebral artery (MCA) of the conscious male Sprague–Dawley rat. Ten minutes after the administration of Et-1, mean arterial blood pressure had increased by 20% and profound reductions in local cerebral blood flow (up to 93%) were observed within those brain areas supplied by the MCA. In addition, significant increases in local cerebral blood flow were observed within the globus pallidus (100%), substantia nigra pars reticulata (48%), ventrolateral thalamus (65%), and dorsal hippocampus (74%) ipsilateral to the insult. Twenty-four hours following the insult, the pattern of ischaemic damage was similar to that reported previously following permanent occlusion of the rat MCA. It is suggested that perivascular microapplication of Et-1 may provide a useful model for the study of the functional disturbances associated with focal cerebral ischaemia in the conscious rat.

Colloidal volume expansion during acute cerebral ischaemia: assessed by local cerebral blood flow and computerized power ratio index

1988 ◽  
Vol 10 (3) ◽  
pp. 151-155 ◽  
Author(s):  
Bruce I. Tranmer ◽  
Cordell E. Gross ◽  
Geoff R. Adey ◽  
Ted S. Keller ◽  
Ken Nagata ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Ischaemia ◽  
Volume Expansion ◽  
Power Ratio ◽  
Local Cerebral Blood Flow ◽  
Acute Cerebral Ischaemia

Local cerebral blood flow and glucose utilization after blood exchange with a hemoglobin-based O2 carrier in conscious rats

1993 ◽  
Vol 265 (4) ◽  
pp. H1243-H1248 ◽  
Author(s):  
K. Waschke ◽  
H. Schrock ◽  
D. M. Albrecht ◽  
K. van Ackern ◽  
W. Kuschinsky
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Glucose Utilization ◽  
Brain Structures ◽  
Control Group ◽  
Local Cerebral Blood Flow ◽  
Conscious Rats ◽  
Cerebral Glucose Utilization ◽  
Arterial Blood ◽  
Blood Exchange

The effects of a blood exchange on cerebral blood flow and glucose utilization were studied. A near to total blood exchange (hematocrit < 3%) was achieved in conscious rats by isovolemic hemodilution. Ultrapurified, polymerized, bovine hemoglobin (UPBHB) served as a blood substitute. Local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCGU) were measured in 34 brain structures of conscious rats by means of the ido[14C]antipyrine and the 2-[14C]-deoxy-D-glucose methods. A group of rats without blood exchange served as control. After blood exchange LCBF increased from 36 to 126% in the different brain structures resulting in a nearly doubled mean cerebral blood flow (+82%). LCGU increased only moderately by 0-24%. Significant increases in LCGU were observed in 16 brain structures. Mean cerebral glucose utilization slightly increased (+14%). The relationship between LCGU and LCBF was found to be tight both in the control group (r = 0.95) as well as after blood replacement (r = 0.94), although it was reset to a higher overall LCBF-to-LCGU ratio. The profound increases in LCBF observed after blood exchange, which were not paralleled by comparable increases in LCGU, might be explained by a reduction of blood viscosity after blood exchange. Additional effects of blood exchange observed in the present study were an increase of mean arterial blood pressure and a decline of heart rate. The results indicate that replacement of blood with the hemoglobin-based oxygen carrier UPBHB appears to meet the cerebral circulatory and metabolic demands of the brain tissue.

Effects of an analogue of thyrotrophin-releasing hormone, RX77368, on infarct size and cerebral blood flow in focal cerebral ischaemia in the rat

1989 ◽  
Vol 67 (10) ◽  
pp. 1345-1350 ◽  
Author(s):  
C. T. O'Shaughnessy ◽  
N. J. Rothwell ◽  
J. Shrewsbury-Gee
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Infarct Size ◽  
Middle Cerebral Artery ◽  
Cerebral Ischaemia ◽  
Lesion Size ◽  
Focal Cerebral Ischaemia ◽  
Thyrotrophin Releasing Hormone ◽  
Releasing Hormone ◽  
Stimulation Of

Effects of a stable analogue of thyrotrophin-releasing hormone, RX77368, on cerebral blood flow and infarct size have been studied in an acute model of cerebral ischaemia in the rat. Two hours after electrocoagulation of the left middle cerebral artery (MCA), the mean area of ischaemia (± SEM), determined histochemically, was 11.5 ± 2.2% of a single hemisphere and blood flow, determined using radiolabeled microspheres, was reduced by 40% in the left forebrain (p < 0.001 compared with sham-operated animals). Administration of RX77368 (50 μg/kg, intracerebroventricularly) within 10 min of arterial occlusion caused a significant (p < 0.01) reduction in mean lesion size to 3.7 ± 1.8% and stimulation of blood flow to the left ischaemic forebrain (60% above saline treated). Peripheral administration of RX77368 (1 mg/kg intraperitoneally) also significantly stimulated blood flow to the ischaemic forebrain and caused an apparent decrease in frequency of large infarcted areas of brain tissue, although mean lesion size was not significantly affected. These findings indicate that RX77368 ameliorates tissue damage in acute focal cerebral ischaemia. Such effects may be related to stimulation of cerebral blood flow.Key words: middle cerebral artery, focal cerebral ischaemia, cerebral blood flow, thyrotrophin-releasing hormone analogue.

scholarly journals Measurement of Local Cerebral Blood Flow with [14C]Iodoantipyrine in the Mouse

1988 ◽  
Vol 8 (1) ◽  
pp. 121-129 ◽  
Author(s):  
Therese M. Jay ◽  
Giovanni Lucignani ◽  
Alison M. Crane ◽  
Jane Jehle ◽  
Louis Sokoloff
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Time Course ◽  
Local Cerebral Blood Flow ◽  
Sources Of Error ◽  
Arterial Blood ◽  
Appropriate Care ◽  
Rapid Removal ◽  
The Brain

Local cerebral blood flow was measured in the mouse by means of the [14C]iodoantipyrine method. This method has been previously used in the monkey, dog, cat, and rat, but its application to small mammals such as the mouse requires special attention to potential sources of error. The small size of the mouse brain requires special attention to the rapid removal and freezing of the brain to minimize effects of postmortem diffusion of tracer in the tissue. Because of the relatively low diameter/length ratios of the catheters needed for arterial sampling in small animals, substantial errors can occur in the determination of the time course of the [14C]iodoantipyrine concentration in the arterial blood unless corrections for lag time and dead space washout in the catheter are properly applied. Local cerebral blood flow was measured in seven awake mice with appropriate care to minimize these sources of error. The values were found to vary from 48 ml/100 g/min in the corpus callosum to 198 ml/100 g/min in the inferior colliculus. The results demonstrate that the [14C]iodoantipyrine method can be used to measure local cerebral blood flow in the mouse and that the values in that species are, in general, somewhat higher than those in the rat.

scholarly journals Conscious rat PET imaging with soft immobilization for quantitation of brain functions: comprehensive assessment of anesthesia effects on cerebral blood flow and metabolism

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chie Suzuki ◽  
Mutsumi Kosugi ◽  
Yasuhiro Magata
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Pet Imaging ◽  
Fdg Pet ◽  
Brain Function ◽  
Conscious Rat ◽  
Conscious Rats ◽  
Brain Functions ◽  
Anesthetic Agents ◽  
Arterial Blood

Abstract Background Animal brain functions evaluated by in vivo imaging under anesthesia can be affected by anesthetic agents, resulting in incorrect assessment of physiological brain function. We therefore performed dynamic positron emission tomography (PET) imaging of conscious rats using recently reported soft immobilization to validate the efficacy of the immobilization for brain function assessments. We also determined the effects of six anesthetic agents—a mixed anesthetic agent (MMB), ketamine + xylazine (KX), chloral hydrate (Chloral), pentobarbital (PTB), propofol (PF), and isoflurane (IFL)—on brain function by comparison with conscious rats. Results The immobilization enabled 45-min dynamic [18F]FDG-PET acquisition with arterial blood sampling using conscious rats without the use of special techniques or invasive surgery. The spatial resolution and quantitativity of [18F]FDG-PET were not significantly lower for conscious rats than for anesthetized rats. While MMB, Chloral, PTB, and PF showed ubiquitous reduction in the cerebral metabolic rates of glucose (CMRglu) in brain regions, KX and IFL showed higher reductions in cerebellum and interbrain, and cerebellum, respectively. Cerebral blood flow (CBF) was reduced by MMB, KX, PTB, and PF; increased by IFL; and unaltered by Chloral. The magnitude of decrease in CMRglu and CBF for MMB were not larger than for other five anesthetic agents, although blood glucose levels and body temperature can be easily affected by MMB. Conclusion The six anesthetic agents induced various effects on CMRglu and CBF. The immobilization technique presented here is a promising tool for noninvasive brain functional imaging using conscious rats to avoid the effects of anesthetic agents.

Sign in / Sign up

Export Citation Format

Share Document