Abstract

Infection of fish cells with IHNV resulted in gradual increase in cytosolic free Ca^2+ concentration ([Ca^2+]) in CHSE, gradual decrease in [Ca^2+] in FHM, and no significant change in RTG cells. The degree of [Ca^2+] increase or decrease was dependent on the amount of infectious virus, and these [Ca^2+] variations were maximal at 16 hours after virus infection (p.i.) in both cell lines. When the fish cells were infected with inactivated IHNV, evident variation in [Ca^2+] was not observed. Thus, infectivity of IHNV appears to correlate with changes in [Ca^2+] in virus-infected cells. These IHNV-induced [Ca^2+] changes were partially blocked by cycloheximide, but not affected by cordycepin. It seems to be that virus-induced Ca^2+ variations were more related with protein synthesis than RNA synthesis. Various Ca^2+ related drugs were used in search for the mechanisms of the [Ca^2+], changes following IHNV infection of CHSE cells. Decreasing extracellular Ca^2+ concentration or blocking Ca^2+ influx from extracellular media inhibited the IHNV-induced increase in [Ca^2+], in CHSE cells. Similar results were obtained with intracellular Ca^2+ sources are important in IHNV-induced [Ca^2+] increase in CHSE cells.

• Keywords: Infectious Hematopoietic Necrosis Virus(IHNV); calcium; fish cell lines