. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. INSECT HORMONES AND RESPIRATION 329 the morphogenetic process alone are relatively minor. This conclusion is supported by the drastic changes in respiratory metabolism which take place during the 3-day larval-larval molt cycle in the growing 5th instar larvae (cf. Fig. 1) in contrast to a relatively small increase in metabolic intensity found in the ecdysterone induced 3-day larval-larval molt cycles which take place in the non-feeding ligated dauer- larvae (Fig. 6B). Because our measurements were performed in dailv interval
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. INSECT HORMONES AND RESPIRATION 329 the morphogenetic process alone are relatively minor. This conclusion is supported by the drastic changes in respiratory metabolism which take place during the 3-day larval-larval molt cycle in the growing 5th instar larvae (cf. Fig. 1) in contrast to a relatively small increase in metabolic intensity found in the ecdysterone induced 3-day larval-larval molt cycles which take place in the non-feeding ligated dauer- larvae (Fig. 6B). Because our measurements were performed in dailv intervals they would not record any possible short-term effects of ecdysterone on OL. consumption. For this reason we performed an additional experiment with the injections of large doses of ecdysterone into the above described dauerlarvae. The O2 consumption rate was then measured in successive one hr intervals (hiring 24 hrs. The results are shown in Figure 7. It appears that the ecdysterone treated specimens have a slightly 600 u _C ^400 O" ^ 200. 0 5 10 15 20 HOURS FIGI/KK 7. Same as in Figure 6B except that O- consumption readings were taken in 60 min intervals (full line; n = 8 specimens). Broken line (n = 5 specimens) shows O- consump- tion of the controls injected with the solvent alone. The arrow indicates the moment of injection. elevated respiratory rate during the initial 5 hr period after the injection. We are not certain, however, whether this is a specific response to ecdysterone or merely a result of variability in responses to epidermal injury. Somewhat later, from 7 hr alter injections, the individual variations in Oi> consumption diminished. Subsequently, the ecdysterone treated specimens exhibited slow but continuous increase in OL. consumption rate over the control level. DISCUSSION Several authors studying the effect of hormones on respiratory metabolism in insects came to the conclusion that the effects were indirect depending on the degree of morphologic
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
