Relationship between specific gravity, water content, and serum protein extravasation in various types of vasogenic brain edema

Abstract

Vasogenic brain edema was induced in cats by cold injury (six animals), brain tumors (five animals), and brain abscesses (six animals). Water and electrolyte content, specific gravity, blood volume, and the amount of extravasated serum proteins were determined in small tissue samples taken from gray and white matter at various distances from the lesion. Edema was strictly confined to the white matter of the affected hemisphere and declined from the lesion to the more peripheral regions. It was characterized by the extravasation of serum proteins and an increase of water and sodium content with little or unpredictable changes of potassium and blood volume. The calculated sodium content of edema fluid varied between 129 and 135 mueq/ml, and serum protein content between 8.1 and 11.9 mg/ml. In all three types of edema, specific gravity and water content correlated closely with the same slope and intercept of the calculated regression (y = 1.119-0.0011 x, r = -0.91). The results obtained indicate that the main denominator of specific gravity of edematous white matter is water content and that this relationship is not significantly altered by variations of blood volume or serum protein content.

Determination of the Brain–Blood Partition Coefficient for Water in Mice Using MRI

“…Therefore, we corrected for the density of brain tissue in our BBPC calculation. A density of mouse brain of 1.04 g/mL was adopted from Bothe et al (1984), and the BBPC was calculated using Equation (2):…”

Cerebral Water Content in Silicone Oil-Induced Hydrocephalic Rabbits

“…sene-bromobenzene gradient columns to determine the specific gravity of brain tissue was first described by Nelson et al [23]. The method has subsequently been adapted for the quantification of brain edema [3,4,6,18,26,30,34]. Methodological studies have shown that reliable results can be obtained when purity of solu tions, temperature of the column, size of tissue samples, and recording time are held constant [8].…”

Tissue hyperosmolality and brain edema in cerebral contusion

“…A possible cause of tissue osmolality elevation is an oncotic pressure increase resulting from disruption of the blood-brain barrier. 4,9,30,34 Cerebral contusion can increase vascular permeability, leading to leakage of large molecules, such as albumin, from plasma to contused tissue. However, an immunohistochemical study of the postmortem brain from patients with contusion failed to reveal any plasma protein leakage around contused brain areas during this early period.…”