Serum Albumin as an Effective Carrier for Diapause Hormone of the Silkworm, Bombyx mori L. (Lapidoptera : Bombycidae)

Abstract

Effects of serum albumin as a carrier medium for diapause hormone (DH) were examined in the pharate adults of the silkworm, Bombyx mori. The addition of serum albumin clearly increased the effectiveness of highly purified DH injected, especially at the lower doses of DH. At a given dose of DH-A (15 μg/animal) the activity rose according to increasing amounts of serum albumin and attained a maximum level over 125 μg/animal, being unity in the molar ratios of albumin to DH-A. Further serum albumin caused prolonged periods of sensitivity to DH-A. Similar effects were observed in ovalbumin, α-globulin and β-casein when injected as complexes with DH-A. From these results, the usefulness of serum albumin as a carrier medium of DH is discussed in view of the improvement of bioassay system.