Efficient use of dietary galactose in Pieris brassicae
| Autor: | Seppo Turunen |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
0106 biological sciences
0303 health sciences animal structures Physiology fungi Galactitol Midgut Fructose Biology 01 natural sciences Trehalose 010602 entomology 03 medical and health sciences chemistry.chemical_compound Glycolipid chemistry Biochemistry Insect Science Galactose Hemolymph Sugar 030304 developmental biology |
| Zdroj: | Journal of Insect Physiology. 38:503-509 |
| ISSN: | 0022-1910 |
| DOI: | 10.1016/0022-1910(92)90075-o |
| Popis: | d -galactose absorption and its use in lipid synthesis was examined in Pieris brassicae larvae receiving d -[U- 14 C]galactose in the diet. Approximate digestibility of galactose was about 90% in last-instar larvae fed an artificial diet. Absorption was followed by a rapid increase in haemolymph 14 C, but midgut tissue 14 C remained at a relatively low level: after 4 and 48 h of exposure to the label, the haemolymph/midgut tissue ratio of 14 C was 2.1 and 4.6, respectively. HPLC and TLC of haemolymph showed trehalose to be the main labelled sugar. Minor labelled fractions included glucose, but no labelled galactose, fructose or galactitol were present. The data suggest that galactose was completely converted within midgut cells, and glucose was one of the metabolites released into the haemolymph and rapidly synthesized to trehalose in fat body. Further metabolism of galactose in midgut cells was indicated by the synthesis of labelled lipids during galactose absorption. Upon a 4 h exposure to labelled galactose, over 20% of midgut tissue 14 C was recovered from lipids, mainly phosphatidylcholines (28%), phosphatidyl-ethanolamines (28%) and triacylglycerols (14%). The data extend previous knowledge of the use of plant glycolipid components in phytophagous insects by suggesting that galactose is a significant nutrient for such animals. |
| Databáze: | OpenAIRE |
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