scholarly journals Effect of hemic hypoxia on dynamics of GFAP concentrations in the structures of the brain and blood serum of rats

2016 ◽  
Vol 24 (1) ◽  
pp. 143-150 ◽  
Author(s):  
T. I. Duka ◽  
V. I. Chоrna
Keyword(s):  
Blood Flow ◽  
Quantitative Analysis ◽  
Intermediate Filaments ◽  
Regional Differences ◽  
Brain Structures ◽  
Astroglial Cells ◽  
Adult Rats ◽  
Cellular Population ◽  
The Brain ◽  
Neurospecific Protein

This article clarifies the questions on study of hypoxic influence on distribution of filament and soluble forms of GFAP in various structures of the brain (neocortex, cerebellum, hippocampus, striatum, middle brain, pons) and blood of the rats. Quantitative analysis of the contents of GFAP in the brain structures of hypoxic rats has established that hemic hypoxia results in changes in intracellular levels of GFAP forms and also in updating their ratio, which allows one to assume not only a change in astroglial cells, but also testifies to reorganization in the system of intermediate filaments of astrocytes. The level of GFAP substantially changed in all cerebral formations, which was already investigated in the early terms of hypoxic period. Observations showed that hemic hypoxia exerted a varied influence on expression of neurospecific protein in the different structures of cerebrum of rats. Differences in expression of GFAP can be caused by the regional differences in astroglial cellular population, and also their internal features that define the possible answers to hypoxic damage in different functional and morphological structures of the brain. An increase in expression of the investigated form of protein can explain strengthening of astroglial reactivity, a feature of the brain that appears in various types of pathologies of the CNS. Reactive asters in such exhibit hypertrophy and are characterized by an increased level of GFAP, which is an early and reliable indicator of astroglial pathology. An increase in expression of the investigated form of protein may be explained by strengthening of astroglial reactivity, a feature of the brain that appears in various types of pathologies of the CNS. The contents of GFAP in the blood of adult rats, as a result of the hypoxic influence received from it, can indicate a release of GFAP from damaged astrocytes in the blood flow. 

Sympathetic regulation of cerebral blood flow during reflex hypertension

1985 ◽  
Vol 249 (3) ◽  
pp. H672-H680
Author(s):  
P. Lacombe ◽  
M. C. Miller ◽  
J. Seylaz
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Structures ◽  
Systemic Hypertension ◽  
Regional Cerebral Blood ◽  
Acute Hypertension ◽  
Cerebrovascular Autoregulation ◽  
Circulatory Effects ◽  
Sympathetic Regulation ◽  
The Brain

The cerebral circulatory effects of physiological stimulation of the sympathetic nervous system have been examined in the present study. In lightly anesthetized rabbits, reflex sympathetic activation was provoked by bilateral sinus deafferentation and vagotomy. Regional cerebral blood flow (CBF) was measured by the [14C]-ethanol technique and compared in paired brain structures following unilateral superior cervical ganglionectomy. Two subgroups of hypertensive rabbits were statistically distinguished. In the first (19 of 28 rabbits), CBF in the innervated hemisphere was little modified by hypertension but there was a significant side-to-side difference in CBF between the hemispheres. In the second group (9 rabbits) CBF was markedly increased by the systemic hypertension, and little difference was noted between innervated and denervated hemispheres. We demonstrate that, during acute hypertension, the superior cervical system contributes to cerebrovascular autoregulation; this contribution varies according to the brain region studied. In a subgroup of animals, little sympathetic activity could be evidenced, and it is hypothesized that in these rabbits a vasodilatory system was activated that counteracted the myogenic, autoregulatory responses.

scholarly journals Improvement in Local Cerebral Blood Flow Measurement in Gerbil Brains by Prevention of Postmortem Diffusion of [14C]Iodoantipyrine

1992 ◽  
Vol 12 (2) ◽  
pp. 296-300 ◽  
Author(s):  
Takao Hatakeyama ◽  
Saburo Sakaki ◽  
Ko Nakamura ◽  
Shigeru Furuta ◽  
Kenzou Matsuoka
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Liquid Nitrogen ◽  
Brain Structures ◽  
Drying Time ◽  
Modified Method ◽  
Hot Air ◽  
Conventional Drying ◽  
Postmortem Brains ◽  
The Brain

Postmortem diffusion of [14C]iodoantipyrine, which distorts the image of cerebral blood flow, can occur in at least three steps; from decapitation until the brain is frozen, while frozen sections on coverslips are thawed, and when dried sections are applied to x-ray film. In the present study, the first two steps were modified to reduce the time during which brain tissue was wet. When the brains of gerbils were taken out of the skulls and immersed in chilled isopentane (–45°C), 90–95 s elapsed between decapitation until the brain tissues were frozen. However, immersion of whole heads in liquid nitrogen after decapitation decreased the time to 25 s. The autoradiograms had better contrast after the freezing procedure with liquid nitrogen than after that with chilled isopentane. The drying time of the thawed sections was markedly reduced by blowing hot air across the sections on a hot plate, and this resulted in clearer images on autoradiograms. In most of the tissues with values of cerebral blood flow over 100 ml 100 g−1 min−1 as measured using the conventional drying method, the corresponding values were higher if the modified method was used. In contrast, in tissues with values less than 100 ml 100 g−1 min−1, the corresponding values were lower. Moreover, the differences between flows in adjacent small brain structures were less clear if the sections were dried by the conventional method. Reducing the time during which postmortem brains or sections are wet can help prevent [14C]iodoantipyrine diffusion artifacts.

scholarly journals Regional Brain Blood Flow, Blood Volume, and Haematocrit Values in the Adult Rat

1983 ◽  
Vol 3 (2) ◽  
pp. 254-256 ◽  
Author(s):  
Jill E. Cremer ◽  
Malcolm P. Seville
Keyword(s):  
Blood Flow ◽  
Blood Volume ◽  
Brain Regions ◽  
Adult Rats ◽  
Adult Rat ◽  
Systemic Artery ◽  
Significant Difference ◽  
Total Body ◽  
The Brain ◽  
Made In

Measurements of red cell volume, plasma volume, and tissue haematocrit (Hct) were made in 14 brain regions in adult rats using 51Cr-tagged red cells and 125I-labeled human serum albumin. The mean large vessel (systemic artery) Hct was 41.8, total body Hct was 35.3, and of the brain regions, the lowest value (septal nucleus) was 25.91 and the highest (visual cortex) was 32.05. The lowest blood volume was 6.29 μl g−1 (caudate putamen) and the highest was 14.44 μl g−1 (inferior colliculus). There was a significant difference between regions in both blood volume and tissue blood Hct. When brain regions were ranked in order of blood volume, this did not coincide with the order for blood flow.

scholarly journals Effect of mother alcoholization on the activity of ghrelin system in prenatal and early postnatal periods of rat offspring

2015 ◽  
Vol 13 (2) ◽  
pp. 10-13 ◽  
Author(s):  
Marat Igorevich Airapetov ◽  
Platon Platonovich Khokhlov ◽  
Eugeny Rudolfovich Bychkov ◽  
Edgar Arturovich Sekste ◽  
Natalia Dmitrievna Yakushina ◽  
...  
Keyword(s):  
Blood Serum ◽  
Mrna Expression ◽  
Brain Structures ◽  
Postnatal Period ◽  
Receptor Expression ◽  
Dopaminergic Receptors ◽  
Adult Rats ◽  
Ghrelin Receptor ◽  
Chronic Alcoholization ◽  
The Brain

The purpose of the paper was to study both the desacylghrelin (unacylated ghrelin) level in the blood serum and expression of mRNA ghrelin receptor in the brain structures in ontogeny after chronic alcoholization in rats. The results proved that the prenatal effect of ethanol negatively affected the maturation of dopaminergic and ghrelin systems of the brain as well as involvement of ghrelin system in mechanisms of alcohol dependence formation. The decrease of COMT mRNA expression simultaneoully with the increase of expression of D2 long and short isoforms of dopaminergic receptors and misbalance of ghrelin system were observed. Alcoholization of mothers reduced desacylghrelin level in the blood serum in early postnatal period in offsprings although mRNA expression of ghrelin receptor in the brain was elevated. Chronic alcoholization of adult rats also affected the ghrelin system. In the alcoholiztion process, the reduced contents of desacylghrelin in the blood serum with compensatory increase of ghrelin receptor expression in the brain were registered. After withdrawal of ethanol, the recovery of desacylghrelin level (tendency to normalization) was observed.

Heterogeneity of brain blood flow and permeability during acute hypertension

1985 ◽  
Vol 249 (3) ◽  
pp. H629-H637 ◽  
Author(s):  
G. L. Baumbach ◽  
D. D. Heistad
Keyword(s):  
Blood Flow ◽  
Brain Stem ◽  
Blood Brain Barrier ◽  
Regional Differences ◽  
Severe Hypertension ◽  
Brain Barrier ◽  
Acute Hypertension ◽  
Blood Brain ◽  
The Brain ◽  
Increased Blood Flow

The purpose of this study was to examine regional autoregulation of blood flow in the brain during acute hypertension. In anesthetized cats severe hypertension increased blood flow more in cerebrum (159%) and cerebellum (106%) than brain stem (58%). In contrast to the heterogeneous autoregulatory response, hypocapnia produced uniform vasoconstriction in the brain. We also compared vasodilatation during severe hypertension with vasodilatation during hypercapnia. During hypercapnia, blood flow increased as much in brain stem, as in cerebrum and cerebellum. Thus regional differences in autoregulation appear to be specific for autoregulatory stimulus and are not secondary to nonspecific differences in vasoconstrictor or vasodilator capacity. To determine whether the blood-brain barrier is more susceptible to hypertensive disruption in regions with less effective autoregulation, permeability of the barrier was quantitated with 125I-albumin. Severe hypertension produced disruption of the barrier in cerebrum but not in brain stem. Thus there are parallel differences in effectiveness of autoregulation and susceptibility to disruption of the blood-brain barrier in different regions of the brain.

Ultrasound Measurements of Intracranial Structures in Growth-Restricted Neonates with Fetal Blood Flow Redistribution: A Pilot Observational Study

Neonatology ◽  
2020 ◽  
Vol 117 (4) ◽  
pp. 446-452
Author(s):  
Pramod Pharande ◽  
Mohan Krishnamurthy ◽  
Gillian Whiteley ◽  
Arun Sasi ◽  
Atul Malhotra
Keyword(s):  
Blood Flow ◽  
Observational Study ◽  
Prospective Observational Study ◽  
Brain Structures ◽  
Cranial Ultrasound ◽  
Fetal Blood ◽  
The Impact ◽  
The Brain ◽  
Blood Flow Redistribution

<b><i>Background:</i></b> Fetal growth restriction (FGR) is associated with neonatal and long-term neuro-morbidity. Preferential redistribution of blood flow to the brain is a common antenatal adaptation in FGR. The impact of this “brain sparing,” which may signify severity of FGR, on the growth of brain structures has not been studied. <b><i>Aim:</i></b> To compare corpus callosum (CC), cerebellar, and ventricular measurements of FGR neonates with evidence of fetal blood flow redistribution with those of gestation-matched appropriately grown (AGA) neonates. <b><i>Methods:</i></b> This was a pilot, prospective observational study conducted at a tertiary level neonatal unit in Melbourne, Australia. Cranial ultrasound was done between days 1 and 3 of life in FGR and AGA neonates. <b><i>Results:</i></b> Cranial ultrasound on 20 FGR, gestation (mean ± SD) 31.4 ± 3.1 weeks, weight 1,205 ± 463 g, and 20 AGA neonates, 31.1 ± 3.0 weeks, 1,668 ± 490 g, was performed. CC length was significantly decreased in FGR neonates as compared to AGA neonates (35.28 ± 3.47 vs. 38.83 ± 4.05 mm, <i>p</i> = 0.0002). CC was significantly thinner at genu (3.36 ± 0.66 vs. 4.04 ± 0.83 mm, <i>p</i> = 0.007), body (1.97 ± 0.36 vs. 2.27 ± 0.39 mm, <i>p</i> = 0.02), and splenium (4.07 ± 0.76 vs. 4.72 ± 0.75 mm, <i>p</i> = 0.003) in FGR vs. AGA neonates. CC-fastigium length was also significantly decreased (39.65 ± 3.87 vs. 41.96 ± 4.50 mm, <i>p</i> = 0.04). Similarly, FGR neonates showed decreased transverse cerebellar diameter (36.15 ± 5.51 vs. 38.81 ± 7.21 mm, <i>p</i> = 0.02), but ventricular measurements were comparable. In multivariate analysis, these differences were evident independent of the birth weight. <b><i>Conclusions:</i></b>CC and cerebellar measurements are significantly smaller in FGR neonates with fetal blood flow redistribution, which warrants further study.

scholarly journals Eyeballing stroke: Blood flow alterations in the eye and visual impairments following transient middle cerebral artery occlusion in adult rats

2020 ◽  
Vol 29 ◽  
pp. 096368972090580
Author(s):  
Jea-young Lee ◽  
Vanessa Castelli ◽  
Brooke Bonsack ◽  
Julián García-Sánchez ◽  
Chase Kingsbury ◽  
...  
Keyword(s):  
Blood Flow ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Artery Occlusion ◽  
Laser Doppler ◽  
Adult Rats ◽  
Visual Deficits ◽  
Cerebral Artery Occlusion ◽  
The Brain

Middle cerebral artery occlusion in rodents remains a widely used model of ischemic stroke. Recently, we reported the occurrence of retinal ischemia in animals subjected to middle cerebral artery occlusion, owing in part to the circulatory juxtaposition of the ophthalmic artery to the middle cerebral artery. In this study, we examined the eye hemodynamics and visual deficits in middle cerebral artery occlusion-induced stroke rats. The brain and eye were evaluated by laser Doppler at baseline (prior to middle cerebral artery occlusion), during and after middle cerebral artery occlusion. Retinal function-relevant behavioral and histological outcomes were performed at 3 and 14 days post-middle cerebral artery occlusion. Laser Doppler revealed a typical reduction of at least 80% in the ipsilateral frontoparietal cortical area of the brain during middle cerebral artery occlusion compared to baseline, which returned to near-baseline levels during reperfusion. Retinal perfusion defects closely paralleled the timing of cerebral blood flow alterations in the acute stages of middle cerebral artery occlusion in adult rats, characterized by a significant blood flow defect in the ipsilateral eye with at least 90% reduction during middle cerebral artery occlusion compared to baseline, which was restored to near-baseline levels during reperfusion. Moreover, retinal ganglion cell density and optic nerve depth were significantly decreased in the ipsilateral eye. In addition, the stroke rats displayed eye closure. Behavioral performance in a light stimulus-mediated avoidance test was significantly impaired in middle cerebral artery occlusion rats compared to control animals. In view of visual deficits in stroke patients, closely monitoring of brain and retinal perfusion via laser Doppler measurements and examination of visual impairments may facilitate the diagnosis and the treatment of stroke, including retinal ischemia.

scholarly journals Amino Acids That Centrally Influence Blood Pressure and Regional Blood Flow in Conscious Rats

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Yumi Takemoto
Keyword(s):  
Blood Pressure ◽  
Amino Acids ◽  
Blood Flow ◽  
Amino Acid ◽  
Regional Blood Flow ◽  
Brain Structures ◽  
Cardiovascular Research ◽  
Flow Measurements ◽  
Conscious Rats ◽  
The Brain

Functional roles of amino acids have increasingly become the focus of research. This paper summarizes amino acids that influence cardiovascular system via the brain of conscious rats. This paper firstly describes why amino acids are selected and outlines how the brain regulates blood pressure and regional blood flow. This section includes a concise history of amino acid neurotransmitters in cardiovascular research and summarizes brain areas where chemical stimulations produce blood pressure changes mainly in anesthetized animals. This is followed by comments about findings regarding several newly examined amino acids with intracisternal stimulation in conscious rats that produce changes in blood pressure. The same pressor or depressor response to central amino acid stimulations can be produced by distinct mechanisms at central and peripheral levels, which will be briefly explained. Thereafter, cardiovascular actions of some of amino acids at the mechanism level will be discussed based upon findings of pharmacological and regional blood flow measurements. Several examined amino acids in addition to the established neurotransmitter amino acids appear to differentially activate brain structures to produce changes in blood pressure and regional blood flows. They may have physiological roles in the healthy brain, but pathological roles in the brain with cerebral vascular diseases such as stroke where the blood-brain barrier is broken.

Effects of striatal nitric oxide production on regional cerebral blood flow and seizure development in rats exposed to extreme hyperoxia

2015 ◽  
Vol 119 (11) ◽  
pp. 1282-1288 ◽  
Author(s):  
Heath G. Gasier ◽  
Ivan T. Demchenko ◽  
Barry W. Allen ◽  
Claude A. Piantadosi
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Brain Structures ◽  
Nitric Oxide Production ◽  
Regional Cerebral Blood ◽  
Oxide Production ◽  
Arterial Blood ◽  
The Brain

The endogenous vasodilator and signaling molecule nitric oxide has been implicated in cerebral hyperemia, sympathoexcitation, and seizures induced by hyperbaric oxygen (HBO2) at or above 3 atmospheres absolute (ATA). It is unknown whether these events in the onset of central nervous system oxygen toxicity originate within specific brain structures and whether blood flow is diverted to the brain from peripheral organs with high basal flow, such as the kidney. To explore these questions, total and regional cerebral blood flow (CBF) were measured in brain structures of the central autonomic network in anesthetized rats in HBO2at 6 ATA. Electroencephalogram (EEG) recordings, cardiovascular hemodynamics, and renal blood flow (RBF) were also monitored. As expected, mean arterial blood pressure and total and regional CBF increased preceding EEG spikes while RBF was unaltered. Of the brain structures examined, the earliest rise in CBF occurred in the striatum, suggesting increased neuronal activation. Continuous unilateral or bilateral striatal infusion of the nitric oxide synthase inhibitor Nω-nitro-l-arginine methyl ester attenuated CBF responses in that structure, but global EEG discharges persisted and did not differ from controls. Our novel findings indicate that: 1) cerebral hyperemia in extreme HBO2in rats does not occur at the expense of renal perfusion, highlighting the remarkable autoregulatory capability of the kidney, and 2) in spite of a sentinel increase in striatal blood flow, additional brain structure(s) likely govern the pathogenesis of HBO2-induced seizures because EEG discharge latency was unchanged by local blockade of striatal nitric oxide production and concomitant hyperemia.

scholarly journals Distribution of Glut1 Glucose Transporters in Different Brain Structures Compared to Glucose Utilization and Capillary Density of Adult Rat Brains

1997 ◽  
Vol 17 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Karin Zeller ◽  
Sylvia Rahner-Welsch ◽  
Wolfgang Kuschinsky
Keyword(s):  
Glucose Utilization ◽  
Brain Structures ◽  
Capillary Density ◽  
Brain Regions ◽  
Capillary Endothelium ◽  
Tight Coupling ◽  
Adult Rats ◽  
Heterogeneous Distribution ◽  
Adult Rat ◽  
The Brain

Glut1 is a specific transporter system that mediates glucose transfer across the blood–brain barrier (BBB). Although the main location of Glut1 is in the capillary endothelium of the brain, its local distribution in different brain regions is not as well defined. In the present investigation, the local pattern of Glut1 distribution was determined in 13 brain structures using an immunoautoradiographic method developed for this purpose. A polyclonal antibody directed against the C-terminal amino acid sequence of Glut1 was applied to cryosections of rat brains. A secondary antibody was added that had been coupled to [35S]. Results show a heterogeneous distribution of Glut1 in the brain with activities of [35S] ranging from 65% below to 15% above the mean. White matter activity was lower than gray matter activity. For comparison, capillary sections were counted in corresponding cryosections by indirect immunofluorescence using fibronectin antibodies. In addition, local cerebral glucose utilization (LCGU) was analyzed in identical brain structures of conscious rats by the quantitative autoradiographic 2-deoxyglucose method. Significant correlations were found between Glut1 density and either LCGU or capillary density. Results indicate a tight coupling of Glut1 transporter density and capillary density to the LCGU of different BBB structures in adult rats.

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