scholarly journals Brain Water as a Function of Age and Weight in Normal Rats

2021 ◽  
Author(s):  
Allan Gottschalk ◽  
Susanna Scafidi ◽  
Thomas Toung

Rats are frequently used to study water content of normal and injured brain, as well as changes in response to various osmotherapeutic regimens. Magnetic resonance imaging in humans has shown that brain water content declines with age as a result of progressive myelination. The purpose of this study was to quantify changes in brain water content during rat development and aging. Brain water content was measured by standard techniques in 129 normal male Sprague-Dawley rats that ranged in age (weight) from 13 to 149 days (18 to 759 g). Overall, the results demonstrated a decrease from 85.59% to 76.56% water content with increasing age (weight). Nonlinear allometric functions relating brain water to age and weight were determined. These findings provide age-related context for prior rat studies of brain water, emphasize the importance of using similarly aged controls in studies of brain water, and indicate that age-related changes in brain water content are not specific to humans.

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0249384
Author(s):  
Allan Gottschalk ◽  
Susanna Scafidi ◽  
Thomas J. K. Toung

Rats are frequently used for studying water content of normal and injured brain, as well as changes in response to various osmotherapeutic regimens. Magnetic resonance imaging in humans has shown that brain water content declines with age as a result of progressive myelination and other processes. The purpose of this study was to quantify changes in brain water content during rat development and aging. Brain water content was measured by standard techniques in 129 normal male Sprague-Dawley rats that ranged in age (weight) from 13 to 149 days (18 to 759 g). Overall, the results demonstrated a decrease in water content from 85.59% to 76.56% with increasing age (weight). Nonlinear allometric functions relating brain water to age and weight were determined. These findings provide age-related context for prior rat studies of brain water, emphasize the importance of using similarly aged controls in studies of brain water, and indicate that age-related changes in brain water content are not specific to humans.


1993 ◽  
Vol 264 (6) ◽  
pp. F968-F974
Author(s):  
S. Adler ◽  
J. G. Verbalis ◽  
D. Williams

The present studies evaluated whether previously observed impairments in brain buffering during acute hyponatremia were maintained during chronic hyponatremia as well and whether the impairment was due in part to changes in brain water, brain perfusion, or activation of arginine vasopressin (AVP) V1 receptors. Acute (1 and 2 day) and chronic (7 and 14 day) hyponatremia was induced in male Sprague-Dawley rats by constant desmopressin administration in combination with a liquid diet. Brain pH was determined by 31P nuclear magnetic resonance (NMR) in rats anesthetized with N2O and paralyzed with pancuronium. Brain buffering was evaluated by the response to CO2 loading, and brain perfusion was evaluated by 19F-NMR using trifluoromethane washout. Compared with normonatremic controls fed the same diet, brain pH in both acute and chronic hyponatremics was 0.12 pH units lower after 55 min ventilation with 20% CO2 despite identical decreases of approximately 0.35 units in all groups during the first 15 min. Moreover, in the recovery period brain pH overshot basal levels only in normonatremic controls. Brain water content in chronic hyponatremic rats was equal to controls, and brain perfusion was identical in the five groups during CO2 exposure. These results are analogous to those reported during acute hyponatremia induced with AVP and show that the impairment of active brain buffering is maintained during chronic hyponatremia and is unrelated to brain water content, perfusion, tissue catabolism, or AVP V1 receptor activation.


2020 ◽  
Vol 53 (1) ◽  
Author(s):  
Huihui Wu ◽  
Nini Yu ◽  
Xia Wang ◽  
Yina Yang ◽  
Hui Liang

Abstract Background Neuronal apoptosis plays a critical event in the pathogenesis of early brain injury after subarachnoid hemorrhage (SAH). This study investigated the roles of Tauroursodeoxycholic acid (TUDCA) in attenuate neuronal apoptosis and underlying mechanisms after SAH. Methods Sprague–Dawley rats were subjected to model of SAH and TUDCA was administered via the internal carotid injection. Small interfering RNA (siRNA) for TGR5 were administered through intracerebroventricular injection 48 h before SAH. Neurological scores, brain water content, Western blot, TUNEL staining and immunofluorescence staining were evaluated. Results TUDCA alleviated brain water content and improved neurological scores at 24 h and 72 h after SAH. TUDCA administration prevented the reduction of SIRT3 and BCL-2 expressions, as well as the increase of BAX and cleaved caspase-3.Endogenous TGR5 expression were upregulated after SAH and treatment with TGR5 siRNA exacerbated neurological outcomes after SAH and the protective effects of TUDCA at 24 h after SAH were also abolished by TGR5 siRNA. Conclusions Our findings demonstrate that TUDCA could attenuated neuronal apoptosis and improve neurological functions through TGR5/ SIRT3 signaling pathway after SAH. TUDCA may be an attractive candidate for anti-apoptosis treatment in SAH.


2006 ◽  
Vol 105 (6) ◽  
pp. 1176-1181 ◽  
Author(s):  
Michael M. Todd ◽  
Johann Cutkomp ◽  
Johnny E. Brian

Background Furosemide and mannitol are used to reduce intracranial pressure, but the impact of furosemide on edema of injured brain is unclear. The authors examined the effects of furosemide and mannitol, alone and in combination, on brain water content in brain-injured rats. Methods Anesthetized rats were subjected to a 2.2-atm left hemispheric fluid percussion injury. Two and three-quarters hours later, animals received 0.5, 1, 4, or 8 g/kg mannitol; 8 mg/kg furosemide; a combination of 4 g/kg mannitol plus 4 mg/kg furosemide; or 8 g/kg mannitol plus 8 mg/kg furosemide. One hour later (4 h after injury), plasma osmolality was measured, and hemispheric water content was determined by drying. Other animals were subjected to injury without drug treatment (impact only) or did not undergo injury (control). Pairwise group comparisons regarding the effects of mannitol and furosemide were restricted to only four groups: impact only, 8 g/kg mannitol, 8 mg/kg furosemide, and 8 g/kg mannitol plus 8 mg/kg furosemide. Results The water content of both hemispheres in the impact-only group was greater than in the control group (left greater than right). Mannitol, 8 g/kg, increased osmolality from 306 +/- 4 to 351 +/- 6 mOsm/kg (mean +/- SD) and reduced water content in the left hemisphere from 80.06 +/- 0.84% (impact only) to 78.24 +/- 0.73%. Furosemide, 8 mg/kg, had no effect on osmolality or water content. Brain water in animals treated with 8 g/kg mannitol plus 8 mg/kg furosemide did not differ from that seen with 8 g/kg mannitol alone. Conclusions Mannitol increased plasma osmolality and reduced water content of the injured and contralateral hemispheres, whereas the authors observed no effect of furosemide when given either alone or in combination with mannitol.


2020 ◽  
Vol 12 (1) ◽  
pp. 001-008
Author(s):  
Ting Liu ◽  
Xing-Zhi Liao ◽  
Mai-Tao Zhou

Abstract Background Brain edema is one of the major causes of fatality and disability associated with injury and neurosurgical procedures. The goal of this study was to evaluate the effect of ulinastatin (UTI), a protease inhibitor, on astrocytes in a rat model of traumatic brain injury (TBI). Methodology A rat model of TBI was established. Animals were randomly divided into 2 groups – one group was treated with normal saline and the second group was treated with UTI (50,000 U/kg). The brain water content and permeability of the blood–brain barrier were assessed in the two groups along with a sham group (no TBI). Expression of the glial fibrillary acidic protein, endthelin-1 (ET-1), vascular endothelial growth factor (VEGF), and matrix metalloproteinase 9 (MMP-9) were measured by immunohistochemistry and western blot. Effect of UTI on ERK and PI3K/AKT signaling pathways was measured by western blot. Results UTI significantly decreased the brain water content and extravasation of the Evans blue dye. This attenuation was associated with decreased activation of the astrocytes and ET-1. UTI treatment decreased ERK and Akt activation and inhibited the expression of pro-inflammatory VEGF and MMP-9. Conclusion UTI can alleviate brain edema resulting from TBI by inhibiting astrocyte activation and ET-1 production.


2021 ◽  
pp. 1-9
Author(s):  
Qinhan Hou ◽  
Hongmou Chen ◽  
Quan Liu ◽  
Xianlei Yan

Traumatic brain injury (TBI) can induce neuronal apoptosis and neuroinflammation, resulting in substantial neuronal damage and behavioral disorders. Fibroblast growth factors (FGFs) have been shown to be critical mediators in tissue repair. However, the role of FGF10 in experimental TBI remains unknown. In this study, mice with TBI were established via weight-loss model and validated by increase of modified neurological severity scores (mNSS) and brain water content. Secondly, FGF10 levels were elevated in mice after TBI, whereas intraventricular injection of Ad-FGF10 decreased mNSS score and brain water content, indicating the remittance of neurological deficit and cerebral edema in TBI mice. In addition, neuronal damage could also be ameliorated by stereotactic injection of Ad-FGF10. Overexpression of FGF10 increased protein expression of Bcl-2, while it decreased Bax and cleaved caspase-3/PARP, and improved neuronal apoptosis in TBI mice. In addition, Ad-FGF10 relieved neuroinflammation induced by TBI and significantly reduced the level of interleukin 1β/6, tumor necrosis factor α, and monocyte chemoattractant protein-1. Moreover, Ad-FGF10 injection decreased the protein expression level of Toll-like receptor 4 (TLR4), MyD88, and phosphorylation of NF-κB (p-NF-κB), suggesting the inactivation of the TLR4/MyD88/NF-κB pathway. In conclusion, overexpression of FGF10 could ameliorate neurological deficit, neuronal apoptosis, and neuroinflammation through inhibition of the TLR4/MyD88/NF-κB pathway, providing a potential therapeutic strategy for brain injury in the future.


1988 ◽  
Vol 8 (1) ◽  
pp. 89-95 ◽  
Author(s):  
John J. Grome ◽  
Gerlinde Gojowczyk ◽  
Wolfgang Hofmann ◽  
David I. Graham

This study was carried out with a recently developed model of focal cerebral ischemia in the rat based on the photochemical induction of thrombotic stroke using the dye Rose Bengal. We examined the change in the volume of the lesion and brain water content, in separate groups of rats, at different times (1, 4, 24, 72, and 168 h) after the induction of the ischemic lesion. The volume of ischemic damage increased rapidly between 1 and 24 h after the ischemic insult and decreased between 24 and 168 h. The lesion at 168 h was significantly larger than that following 1 h of ischemia and similar to that obtained at 4 h, suggesting that the maximum extent of tissue damage (without the involvement of significant edema) was reached within the first 4 h in this model. The enlargement of the lesion after 4 h correlated closely with changes in brain water content.


1997 ◽  
Vol 40 (3) ◽  
pp. 57-60
Author(s):  
Věroslav Golda ◽  
Jiřina Hilgertová

Two series of experiments were performed. In the first one experiments were carried out in Koletsky genetically hypertensive lean female rats and in the normotensive female rats of Wistar strain. Glucose intolerance was induced by oligemic brain hypoxia (4 hours of occlusion of both common carotid arteries followed by 44 hours reperfusion). Brain water content were used as a marker of brain edema.Changes in insulinemia and specific insulin binding were used as expression of regulative mechanisms participating in modification of glucose tolerance. The effect of terguride (trans-dihydro- lisuride) was tested.Brain hypoxia induced glucose intolerance in both strains of rat but brain edema was found only in the normotensive females. Both abnormalities were alleviated by terguride treatment. Basal glycaemia was not changed either by the brain hypoxia or by terguride treatment,except normoternsive female where brain hypoxia induced hyperglycaemia. The second series of experiments were carried out in the normotensive females. The arrangement of experiments was the same as in first series except omission of the final glucose tolerance test. Brain hypoxia causes increase in brain water content. The mentioned elevation of brain water content was alleviated by terguride treatmnet. Insulin binding to erythrocytes was not influenced by brain hypoxia. Terguride treatment shows decrease of insulin binding to erythrocytes. Brain hypoxia elevates insulinemia which was not alleviated by terguride treatment.


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