Intestinal absorption of radioactive long-chain saturated fatty acids by the larval dragon-fly Aeshna cyanea and co-absorptive effects of other stable fatty acids

Differential absorption and esterification of dietary long-chain fatty acids by larvae of the dragonfly,Aeshna cyanea

“…In the midgut wall, the highest incorporation of both fatty acids of each infusate was found in the PL fraction. This was consistent with previous results with fatty acid doses in the range of nmoles (Wachtmann and Komnick, 1993;Komnick and Wachtmann, 1995). Surprisingly, the second highest lipid classes in the midgut wall at 3 h were both free fatty acids regardless of the infusate.…”

“…So far, two cytosolic FABP have been demonstrated in the midgut of Manduca sexta (Smith et al, 1992). It was previously reported for Aeshna larvae (Komnick and Wachtmann, 1995) that the uptake of radiolabeled palmitic and stearic acids from low doses greatly decreased when the infusates contained high doses of stable mono-and polyunsaturated FFA such as myristoleic (14:1), oleic (18:1), and arachidonic (20:4) acids. Simultaneously, the incorporation of the radiolabeled saturated FFA into TG increased, while the incorporation into PL decreased.…”

“…Zoophagous larvae of the dragonfly Aeshna cyanea can absorb a large variety of fatty acids regardless of chain length, saturation, and number, position, and configuration of double bonds (Komnick, 1987(Komnick, , 1991Bauerfeind and Komnick, 1989;Komnick and Wachtmann, 1995). Several authors (e.g., Blomstrand and Dahlbäck, 1960;Kayden et al, 1963;Wood et al, 1964;Zilversmit, 1965) have reported that in mammals the fatty acid composition of the triacylglycerols, which comprise about 95% of chylomicrons, closely resembles that of the diet, indicating that they are absorbed by the intestine without any preference, i.e., in the same proportion as they are present in the intestinal lumen.…”

“…The intermediates FFA, MG, and DG as well as CE are usually minor lipid classes of the tissues. Apart from the esterification of orally infused radiolabeled FFA (12:0, 16:0, 18:0, and 18:1, Wachtmann and Komnick, 1993;Komnick and Wachtmann, 1995), very little is known about the fatty acid composition of these lipid classes.…”

Digestion of phosphatidylcholines, absorption, and esterification of lipolytic products byAeshna cyanea larvae as studied in vivo and in vitro

“…Absorption of radiolabelled FFA and glycerol and their incorporation into midgut tissue PL and AG were also reported for Locusta migratoria Tietz, 1973, 1978). FFA can also be esterified with endogeneous cholesterol and short-chain alcohol as previously shown (Wachtmann and Komnick, 1993;Komnick and Wachtmann, 1995). Apart from the small amounts and traces of TG, MG, FFA, and various PL, DG is the major lipid class released into the haemolymph.…”