EFFECT OF A TREHALASE INHIBITOR, VALIDOXYLAMINE-A, ON OOCYTE DEVELOPMENT AND OOTHECA FORMATION IN PERIPLANETA-AMERICANA (BLATTODEA, BLATTIDAE)

Injection of a specific trehalase inhibitor, validoxylamine A (VAA), s uppressed oocyte development in the American cockroach, Periplaneta am ericana. Octheca formation was also affected by the same treatment. In hibition of trehalases of ovaries and thoracic muscles in P. americana in vitro by VAA was very strong; I-50 values were 5.0 x 10(-9) M and 1.4 x 10(-8) M, respectively. When the inhibition of trehalase activit y was measured after injection of VAA (5 and 50 mu g/insect) into cock roaches, more than 90% of the activity in the ovaries was inhibited. T he high level of inhibition lasted 2 weeks at the higher dosage, but r ecovery of activity was observed in the second week following the inje ction of the lower dosage. VAA injection also inhibited the muscular t rehalase but to a lesser degree than the ovarian trehalase. Enhancemen t of haemolymph trehalose concentration and the maintenance of its hig her level after the injection of VAA suggested strong inhibition of tr ehalase in various tissues of the cockroach. It is speculated that the uptake of materials required for oocyte development as well as the en ergy supply was prevented through the inhibition of trehalase.