Y. Oda et al., Involvement of adipokinetic hormone in the homeostatic control of hemolymph trehalose concentration in the larvae of Bombyx mori, ARCH INS B, 45(4), 2000, pp. 156-165
Prior to wandering, 5th instar larvae of the silkworm, Bombyx mori, maintai
n constant hemolymph titers of trehalose, Head ligation of day 3, 5th insta
r larvae significantly decreased the hemolymph trehalose concentrations, bu
t the concentrations did not decrease in starved larvae. After being dilute
d by replacement of larval hemolymph with insect Ringer's solution, the tre
halose concentrations recovered the initial levels in 90 min in the non-lig
ated larvae, while they were not restored in 90 min in the neck-ligated lar
vae. These results suggest that a head factor(s) with hypertrehalosemic act
ivity is involved in the homeostatic control of hemolymph trehalose concent
ration. When adipokinetic hormone (AKH) was injected into neck-ligated larv
ae, the trehalose concentrations increased in 2 h and decreased thereafter.
Repeated injections of AKH every 4 h maintained the concentrations for 12
h. These findings suggest that AKH induces a hypertrehalosemic response and
is involved in the homeostasis of hemolymph trehalose concentration in the
larval feeding period. Arch. Insect Biochem. Physiol. 45:156-165, 2000. (C
) 2001 Wiley-Liss, Inc.