Red cell aggregation and viscoelasticity of blood from seals, swine and man.

RBC aggregation and viscoelasticity parameters were determined for 40% suspensions of washed cells in autologous plasma from elephant seals (ES), Mirounga angustirostris, ringed seals (RS), Phoca hispida, and swine, (SS), Sus scrofa. Interspecific comparisons including human (HS) blood data revealed unusual rheological properties of seal blood relative to that from pigs or man: 1) RBC aggregation extent, rate and sedimentation were lower for seals (AI = 0, ZSR = .40, ESR = 0 for RS blood) relative to humans; 2) Viscous (n') and elastic (n") components of complex viscosity (OCRD) were lower for both seal species relative to SS blood, but only at shear rates less than or equal to 10 sec-1 (P less than 0.05), while n"/n' ratios for RS blood were lower than HS blood at all shear rates (P less than 0.01); 3) Blood viscosity measurements for RS and SS blood from rotational viscometry (Contraves) were consistent with OCRD data; 4) Seal plasma fibrinogen levels were low compared to pigs or humans (RS fibrinogen = -43% v. HS and -57% v. SS; ES fibrinogen = -58% v. HS and -69% v. SS). Electrophoretic mobility of RS red cells was +25% relative to those of humans. These results demonstrate differences in hemorheological indices among mammalian species and suggest the value of comparative rheologic studies.