A comparison has been made of the effects of juvenile hormone (JH) on the binding characteristics for ouabain of microsomes prepared from brain and from cells of the follicular epithelium surrounding previtellogenic or vitellogenic oocytes in Rhodnius. JH has no effect on the binding of ouabain to brain microsomes and decreases the Kd, but does not alter the Bmax for previtellogenic follicle cells. For vitellogenic follicle cells, Scatchard analysis reveals a curvilinear relationship, which is interpreted as indicating that a new population of JH-sensitive ouabain-binding sites develops as the follicle cell enters vitellogenesis. These results are related to earlier data obtained on the effect of JH on ATPase activity, volume changes in isolated follicle cells, and the development of spaces between the cells of the follicular epithelium.
A specific photoaffinity label for hemolymph and ovarian juvenile hormone-binding proteins in Leucophaea maderae.