. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 124 LUCY CHER I! AS AND PETER CHERBAS in the squashbug .Inasa tristis and the cabbage bug Murgantia liistrioiiica. It is not unreasonable, then, that two hours should be required in the much larger, diapausing polyphemus pupa. What was surprising was the capricious quality of the insect circulatory system as illustrated by the diverse patterns of mixing in Figure 1 : at one point in 'Figure Ib, there is a fourteen-fold difference in inulin concentration between wing and antenna. The path of injected material, and presumably
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 124 LUCY CHER I! AS AND PETER CHERBAS in the squashbug .Inasa tristis and the cabbage bug Murgantia liistrioiiica. It is not unreasonable, then, that two hours should be required in the much larger, diapausing polyphemus pupa. What was surprising was the capricious quality of the insect circulatory system as illustrated by the diverse patterns of mixing in Figure 1 : at one point in 'Figure Ib, there is a fourteen-fold difference in inulin concentration between wing and antenna. The path of injected material, and presumably of an endogenous secretion as well, is not predictable. If hormone binding and breakdown are spatially separated, even a very high binding constant might not ensure efficient utilization of a S (ug/g live weight) FIGURE 6. The initial rate of metabolism of a-ecdysone as a function of injected dose. The rate was calculated from the first two experimental values in graphs such as those in Figure 5; thus, the lag time was excluded from the calculation. The abscissa (S) is the injected dose divided by the pupa's weight. The curve is plotted from the least-squares best line in the reciprocal plot in the inset. The rate of distribution of water was not measurably different from that of inulin. From this observation, the minimum rate of exchange of water between blood and cells can be calculated to be three-quarters of the amount of water in the blood per hour. The distribution of ecdysone Ecdysone reaches its "equilibrium" concentration within about 2 hours after injection. If a carrier is involved, either in the blood or in the target cells, it should be possible to saturate it, making it the rate-limiting step in the hormone's equilibration. The fact that doses up to 10 /xg of a-ecdysone or 100 ^g of /8-ecdysone did not reduce the rate of distribution suggests that a carrier is not involved. In preliminary experiments, we have attempted to detect mac
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
