ABSTRACT
The degree of red cell aggregation is dependent upon multiple conditions. The purpose of these experiments was to ultrasonically determine the threshold and reversibility of human red cell aggregation to extreme pH changes at varying shear rates. Real-time B- and A-mode ultrasonography were used to measure echogenicity. Measurements were recorded at original, acidic, and alkaline pH and following return of both acidic and alkaline pH to neutral pH levels. The results showed that 1) neutral red cell suspensions did not become echogenic at any shear rate; 2) acidification produced a shear-related, partly reversible echogenicity; and 3) alkalinization caused a less intense but more shear-resistant and less reversible echogenicity. Alkalinization produced a microscopically discernible greater persistence of intense red cell aggregation. Cell membrane protein loss was detected by electrophoresis.
