. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CATECHOLAMINES IN OYSTER LARVAE 635 A. nA UJ a. o o. S 10 RETENTION TIME (MIN) 20 10 RETENTION TIME (MIN) 1 20 FIGURE 1. Typical chromatographs obtained using HPLC with electrochemical detection as de- scribed in the text. (A) Solution of catecholamine standards (DOPA: 230 pg; NE: 340 pg; EPI: 340 pg; IS: 460 pg; DA: 340 pg). (B) Alumina extract of a homogenate of whole, competent oyster larvae. Note the change in scale for the DA peak. DOPA: dihydroxyphenylalanine; NE: norepinephrine; EPI: epinephrine; IS: intern
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CATECHOLAMINES IN OYSTER LARVAE 635 A. nA UJ a. o o. S 10 RETENTION TIME (MIN) 20 10 RETENTION TIME (MIN) 1 20 FIGURE 1. Typical chromatographs obtained using HPLC with electrochemical detection as de- scribed in the text. (A) Solution of catecholamine standards (DOPA: 230 pg; NE: 340 pg; EPI: 340 pg; IS: 460 pg; DA: 340 pg). (B) Alumina extract of a homogenate of whole, competent oyster larvae. Note the change in scale for the DA peak. DOPA: dihydroxyphenylalanine; NE: norepinephrine; EPI: epinephrine; IS: internal standard, dihydroxybenzylamine; DA: dopamine. Unidentified peaks: I (probably dihydroxy- phenylalanine), II (probably epinephrine). III (unknown). Figure 3 shows the corresponding amounts of DA present in the larvae and spat as a function of larval size. These data are also shown in Table I along with the NE data. It can be seen that there is significantly more DA than NE present in the larvae and spat. There are no statistically significant trends in the DA data although there is a tendency for higher values in smaller larvae; the DA content per ;ug protein is rela- tively constant throughout the larval life. The DA levels in small, middle-sized, and large larvae are ± , ± , and ± pg/Mg protein, respectively. Like NE, the DA levels ( ± pg/yug protein) do not change during the first 24 h following metamorphosis compared to pre-metamorphic values. Unlike the NE content, there is no increase in the DA content corresponding to the onset of larval competence. The ratio of DA:NE decreases during larval development from a value of about 180 for small larvae to about 17 for middle-sized larvae and finally to about 7 for the largest (competent) larvae and spat. Because there is little change in DA. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appeara
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
