Effect of heparin on hemagglutination by pseudorabies virus.

Heparin inhibited hemagglutination (HA) by pseudorabies virus (PRV), but not HA by Akabane virus, bovine adenovirus type 7, Fukuoka virus, Getah virus, Japanese encephalitis virus, and parainfluenza virus type 3 belonging to the families Bunyaviridae, Adenoviridae, Rhabdoviridae, Togaviridae, Flavivi-idae, and Paramyxoviridae, respectively. The minimal inhibitory concentration of heparin required to inhibit 8 HA U of PRV ranged from 0.005 to 0.01 U/ml. Mouse erythrocytes failed to combine with the HA inhibitory factor of heparin. On the other hand, mouse erythrocytes treated with heparinase had greatly reduced agglutinability by PRV. Virus-heparin complex formation could be observed by sedimenting heparin with the virus particles.