LIPOPHORIN INHIBITS THE ADHESION OF COCKROACH (PERIPLANETA-AMERICANA) HEMOCYTES INVITRO

Lipophorin and lipophorin-deficient plasma, purified by KBr density ultracentrifugation, were tested for their ability to inhibit the adhesion of cockroach (Periplaneta americana) haemocytes in vitro. Haemocytes resuspended in purified lipophorin, either in the absence or presence of Ca2+, remained non-adherent and retained a discoid morphology in vitro for at least 30 min. In contrast, haemocytes incubated either with or without Ca2+ for 30 min in lipophorin-deficient plasma, bovine serum albumin, or saline alone adhered and flattened onto glass coverslips. This finding is important since to date it has been difficult to maintain insect haemocytes in a non-adhesive state in vitro.