Hypermetabolic Response Induced by Juvenile Hormone Analogues in an Insect

Some synthetic analogues o f insect juvenile hormone cause tremendous rise o f respiratory m e­ tabolism in the last larval instar o f Dermestes maculatus. The 0 2 consumption values occasionally found in these hypermetabolic larvae (20 m l/g /h ) can be classified among the most intensive res­ piratory rates ever recorded in living organisms. The phenomenon is directly related to the dose o f juvenile hormone activity and it is dependent on nutrition. The mechanism o f such specific m eta­ bolic action o f juvenile hormone is based on complete oxidation o f the dietary fatty acids, provid­ ing metabolic water for larval somatic growth. The excessive amounts o f energy created by hy­ permetabolism are partly converted to heat, suggesting uncoupling o f phosphorylation. Some other specific endocrinological features associated with hypermetabolism have been discussed.