Inhibition of oocyte development by a trehalase inhibitor, validoxylamine A, in Periplaneta americana

Injection of validoxylamine A (VAA), a specific trehalase inhibitor, suppressed oocyte development in the American cockroach, Periplaneta americana. Trehalases of the ovary, accessory gland and fat body in the cockroach were strongly inhibited by the injection of VAA. Elevation of hemolymph trehalose concentration was observed indicating inhibition of trehalose metabolism in the tissues. In control cockroaches, vitellin accumulated in the ovary in parallel with oocyte development, and the amount of vitellogenin in the hemolymph changed showing negative correlation with the uptake of vitellogenin to the ovary. In VAA-injected cockroaches, vitellogenin production was suppressed in the early stage of oocyte development; uptake of vitellogenin by the ovary reduced in the late stage and, consequently, vitellogenin accumulated in the hemolymph. It is concluded from these results that the primary effect of VAA occurs in the vitellogenin production and the vitellogenin intake for the oocyte development.