scholarly journals Cerebral Blood Flow with the Indicator Fractionation of [14C]Iodoantipyrine: Effect of Paco2 on Cerebral Venous Appearance Time

1991 ◽  
Vol 11 (2) ◽  
pp. 236-241 ◽  
Author(s):  
Stephen C. Jones ◽  
Ender Korfali ◽  
Sam A. Marshall

The indicator fractionation technique using a diffusible indicator as a tracer for the determination of CBF has been used for numerous investigations of the cerebral circulation and its pathophysiology. The diffusible tracer is “trapped” in the brain based on the proper delay between tracer injection and cessation of the cerebral circulation by decapitation before the appearance of the tracer in the cerebral venous circulation. If this delay is too long, the quantitative assumption of the indicator fractionation technique will not be met, and CBF values will be underestimated. In 13 Sprague-Dawley rats anesthetized with pentobarbital, the appearance of [14C]iodoantipyrine at the torcular was assessed as a function of Paco2. An inverse linear relationship between Paco2 (in millimeters of mercury) and cerebral venous appearance, Ta (in seconds), was established with the regression equation Ta = −0.0842 · Paco2 + 12.3 ( R2 = 0.70, slope significantly different from zero, p < 0.001). Ta varied between 5 and 12 s and Paco2 varied between 84 and 18 mm Hg, respectively. Thus, in low-flow states, the decapitation time may be lengthened to 12 s, whereas in high-flow states, the time must be 5 s to eliminate the possibility of backflux of tracer out of the brain.

1988 ◽  
Vol 64 (5) ◽  
pp. 1829-1836 ◽  
Author(s):  
S. Adler ◽  
V. Simplaceanu ◽  
C. Ho

Buffering capacity of most tissues is composed of both rapid and slow phases, the latter presumably due to active acid extrusion. To examine the time course of brain buffering the brain pH of Sprague-Dawley rats was measured using 31P-nuclear magnetic resonance. The effect on brain pH of 30- or 58-min exposures to 20% CO2 followed by 30- or 38-min recovery periods, respectively, was studied. Brain pH reached its lowest value after a 15-min exposure to elevated CO2, thereafter slowly and steadily increasing. During recovery brain pH rose rapidly in the first 5 min exceeding control brain pH by 0.08 pH units. Brain pH fell during the next 30 min despite increases in blood pH and decreases in blood CO2 tension. Calculated intrinsic brain buffering rose steadily threefold during the last 40 min of CO2 exposure and during the final 30 min of recovery. These data show that in rat brain there is a temporally late buffering process, most likely active acid extrusion, requiring greater than 30 min for full activation and at least 30 min for discontinuation.


Author(s):  
Shams M. Ghoneim ◽  
Frank M. Faraci ◽  
Gary L. Baumbach

The area postrema is a circumventricular organ in the brain stem and is one of the regions in the brain that lacks a fully functional blood-brain barrier. Recently, we found that disruption of the microcirculation during acute hypertension is greater in area postrema than in the adjacent brain stem. In contrast, hyperosmolar disruption of the microcirculation is greater in brain stem. The objective of this study was to compare ultrastructural characteristics of the microcirculation in area postrema and adjacent brain stem.We studied 5 Sprague-Dawley rats. Horseradish peroxidase was injected intravenously and allowed to circulate for 1, 5 or 15 minutes. Following perfusion of the upper body with 2.25% glutaraldehyde in 0.1 M sodium cacodylate, the brain stem was removed, embedded in agar, and chopped into 50-70 μm sections with a TC-Sorvall tissue chopper. Sections of brain stem were incubated for 1 hour in a solution of 3,3' diaminobenzidine tetrahydrochloride (0.05%) in 0.05M Tris buffer with 1% H2O2.


2021 ◽  
Vol 12 (2) ◽  
pp. 1272-1275
Author(s):  
Angu Bala Ganesh K S V ◽  
Sujeet Shekhar Sinha ◽  
Kesavi Durairaj ◽  
Abdul Sahabudeen K

Naphthalene is a bicyclic aromatic constituent commonly used in different domestic and marketable applications comprising soil fumigants, lavatory scent disks and mothballs. Accidentally, workers, children and animals are exposed to naphthalene mothballs, so there is a need to study the pathology behind this chemical toxicity. The current study was carried out to assess the ultra structural changes of basolateral amygdaloid nuclei in the Sprague Dawley rats brain in association to naphthalene toxicity. The toxicity model group was administered with naphthalene (200 and 400mg) using corn oil as a vehicle for 28 days. The post delayed toxicity of naphthalene high dose ingestion was also assessed in rats. After the experimental period, the brain tissue was processed to observe the ultra structural changes using a transmission electron microscope. The alterations in cell organelles, nuclei damage, mitochondrial swelling, chromatin condensation suggested naphthalene induced damage in the neurons of the basolateral amygdala of the brain in the toxicity model group. These experimental trials provide information about the alert of mothball usage in the home and identify risks linked with accidental exposure and misuse.


2003 ◽  
Vol 285 (2) ◽  
pp. R420-R428 ◽  
Author(s):  
Andrej A. Romanovsky ◽  
Naotoshi Sugimoto ◽  
Christopher T. Simons ◽  
William S. Hunter

The organum vasculosum laminae terminalis (OVLT) has been proposed to serve as the interface for blood-to-brain febrigenic signaling, because ablation of this structure affects the febrile response. However, lesioning the OVLT causes many “side effects” not fully accounted for in the fever literature. By placing OVLT-lesioned rats on intensive rehydration therapy, we attempted to prevent these side effects and to evaluate the febrile response in their absence. After the OVLT of Sprague-Dawley rats was lesioned electrolytically, the rats were given access to 5% sucrose for 1 wk to stimulate drinking. Sucrose consumption and body mass were monitored. The animals were examined twice a day for signs of dehydration and treated with isotonic saline (50 ml/kg sc) when indicated. This protocol eliminated mortality but not several acute and chronic side effects stemming from the lesion. The acute effects included adipsia and gross (14% of body weight) emaciation; chronic effects included hypernatremia, hyperosmolality, a suppressed drinking response to hypertonic saline, and previously unrecognized marked (by ∼2°C) and long-lasting (>3 wk) hyperthermia. Because the hyperthermia was not accompanied by tail skin vasoconstriction, it likely reflected increased thermogenesis. After the rats recovered from the acute (but not chronic) side effects, their febrile response to IL-1β (500 ng/kg iv) was tested. The sham-operated rats developed typical monophasic fevers (∼0.5°C), the lesioned rats did not. However, the absence of the febrile response in the OVLT-lesioned rats likely resulted from the untreatable side effects. For example, hyperthermia at the time of pyrogen injection was high enough (39–40°C) to solely prevent fever from developing. Hence, the changed febrile responsiveness of OVLT-lesioned animals is given an alternative interpretation, unrelated to febrigenic signaling to the brain.


2020 ◽  
Author(s):  
Mengping Huang ◽  
Xin Lu ◽  
Xiaofeng Wang ◽  
Jian Shu

Abstract Background Diffusion tensor imaging (DTI) is mainly used for detecting white matter fiber in the brain. From this, DTI has been applied to assess fiber in liver disorders by prior studies. But non-sufficient data has been obtained if DTI could be used for exactly staging chronic hepatitis. This study is to assess the value of DTI for staging of liver fibrosis (F), necroinflammatory activity (A), and steatosis (S) of chronic hepatitis in rats. Methods Seventy male Sprague-Dawley rats were divided into control group(n = 10) and experimental group(n = 60). The rat models of chronic hepatitis were established by abdominal subcutaneous injections of 40% CCl4. All rats underwent 3.0T MRI. ROIs were placed on DTI to estimate MR parameters (rADC value and FA value). Histopathology was the reference standard. Multiple linear regression was used to analyze the association between MR parameters and pathology. The differences in rADC value and FA value among pathological stages were evaluated by MANOVA or ANOVA. LSD was used to test the differences between each two groups. ROC analysis was performed. Results The numbers of each pathology were as follows: F0(n = 15), F1(n = 11), F2(n = 6), F3(n = 9), F4(n = 6); A0(n = 8), A1(n = 16), A2(n = 16), A3(n = 7); S0(n = 10), S1(n = 7), S2(n = 3), S3(n = 11), S4(n = 16). The rADC value had a negative correlation with liver fibrosis (r=-0.392, P = 0.008) and inflammation (r=-0.359, P = 0.015). FA value had a positive correlation with fibrosis (r = 0.409, P = 0.005). Significant differences were found in FA value between F4 and F0 ~ F3 (P = 0.03), while no significant differences among F0 ~ F3 were found (P > 0.05). AUC of FA value in differentiating F4 from F0 ~ F3 was 0.909(p < 0.001) with 83.3% Sensitivity, 85.4% specificity when the FA value was at the cut-off of 588.089(× 10− 6mm2/s). Conclusion FA value for DTI can distinguish early cirrhosis from normal, mild and moderate liver fibrosis.


1971 ◽  
Vol 34 (1) ◽  
pp. 77-78 ◽  
Author(s):  
Charles L. Waltematii ◽  
Donald D. Pheuss

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Chun-Bo Jiang ◽  
Ming-Gang Wei ◽  
Yue Tu ◽  
Hao Zhu ◽  
Chun-Qing Li ◽  
...  

Objectives. We investigated the action of triptolide in rats with adriamycin-induced nephropathy and evaluated the possible mechanisms underlying its protective effect against podocyte injury.Methods. In total, 30 healthy male Sprague-Dawley rats were randomized into three groups (normal group, model group, and triptolide group). On days 7, 28, 42, and 56, 24 h urine samples were collected. All rats were sacrificed on day 56, and their blood and renal tissues were collected for determination of biochemical and molecular biological parameters. Expression of miRNAs in the renal cortex was analyzed by a biochip assay and RT-PCR was used to confirm observed differences in miRNA levels.Results. Triptolide decreased proteinuria, improved renal function without apparent adverse effects on the liver, and alleviated renal pathological lesions. Triptolide also elevated the nephrin protein level. Furthermore, levels of miR-344b-3p and miR-30b-3p were elevated in rats with adriamycin-induced nephropathy, while triptolide treatment reversed the increase in the expression of these two miRNAs.Conclusions. These results suggest that triptolide may attenuate podocyte injury in rats with adriamycin-induced nephropathy by regulating expression of miRNA-344b-3p and miRNA-30b-3p.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Renjie Xu ◽  
Mengyue Wang ◽  
Ying Peng ◽  
Xiaobo Li

Isoalantolactone and alantolactone are two major active ingredients that are present in many medicinal plants. In this study, a sensitive and rapid ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed for determination of the two compounds in rat plasma, separately. In this method, an electrospray ionization source was applied and operated in positive ion mode; multiple reaction monitoring (MRM) was selected for quantification using target fragment ions 233.2→187.1 for isoalantolactone (alantolactone) and 245.1→189.1 for internal standard (IS). Retention time of the lactones and IS was within 3.0 min. Further calibration suggested a linear regression can be calculated within 2.5–500 ng/mL for isoalantolactone and 4–500 ng/mL for alantolactone. This method was used to compare the pharmacokinetic characteristics of isoalantolactone and alantolactone at a single dose of 5 mg/kg into male Sprague-Dawley rats by intravenous administration separately. The levels oft1/2, Kel, CL,Cmax, and AUC were significantly increased in the alantolactone group compared to isoalantolactone. These results suggested that isoalantolactone was distributed and eliminated more rapidly than alantolactone in rats when administered, respectively.


1988 ◽  
Vol 69 (6) ◽  
pp. 928-933 ◽  
Author(s):  
Rafael J. Tamargo ◽  
Jonathan I. Epstein ◽  
Henry Brem

✓ Three human glioma cell lines (TE-671 medulloblastoma, U-87 MG glioblastoma, and U-373 MG glioblastoma) were transplanted to the quadrigeminal cistern of the brain in 37 newborn Sprague-Dawley rats and to the subcutaneous space in 30 of their siblings. Two of the three gliomas (the TE-671 medulloblastoma and the U-87 MG glioblastoma) grew both intracranially and subcutaneously. The U-373 MG glioblastoma did not grow in either site. The resulting tumors expressed unique morphological features characteristic of their tissue of origin. The newborn rat represents a model for the heterologous transplantation of human gliomas, providing a biological window for the study of these lesions.


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