Soulages J L, Rimoldi O J, Peluffo O R, Brenner R R
Instituto de Investigaciones Bioquímicas de La Plata, CONICET-UNLP, Facultad de Cs.Médicas, Argentina.
Biochem Biophys Res Commun. 1988 Dec 15;157(2):465-71. doi: 10.1016/s0006-291x(88)80272-9.
Triatoma infestans hemolymph has 0.31 mg/ml of free fatty acids and 2.8 mg/ml of diacylglycerols. Almost all the diacylglycerols are transported by lipophorin whereas free fatty acids are carried by lipophorin and a very high density lipoprotein. The binding of cis-parinaric acid to lipophorin was employed to specify the free fatty acid binding properties of lipophorin. Lipophorin has 10 binding sites of high affinity (3 x 10(7)) and approximately 45 binding sites of low affinity (1 x 10(6)). The relative rate of tissue incorporation of free fatty acids and diacylglycerols was measured by injecting insects with hemolymph previously labeled in both, free fatty acids and diacylglycerols. In this way, the half-life of the hemolymph free fatty acids was estimated to be about 4 min. Based on this result and taking into account the content of free fatty acids and diacylglycerols in hemolymph, the incorporation of free fatty acids, expressed in moles of fatty acids, seems to be 3.4 times higher than that of diacylglycerols. This finding can be applied to other insects.
致倦库蚊血淋巴中游离脂肪酸含量为0.31毫克/毫升，二酰甘油含量为2.8毫克/毫升。几乎所有的二酰甘油都由脂蛋白转运，而游离脂肪酸则由脂蛋白和一种极高密度脂蛋白携带。利用顺式-杷荏酸与脂蛋白的结合来确定脂蛋白结合游离脂肪酸的特性。脂蛋白有10个高亲和力结合位点（3×10⁷）和大约45个低亲和力结合位点（1×10⁶）。通过给昆虫注射预先在游离脂肪酸和二酰甘油中都标记过的血淋巴来测量游离脂肪酸和二酰甘油在组织中的相对掺入率。通过这种方式，估计血淋巴游离脂肪酸的半衰期约为4分钟。基于这一结果并考虑到血淋巴中游离脂肪酸和二酰甘油的含量，以脂肪酸摩尔数表示的游离脂肪酸掺入量似乎比二酰甘油高3.4倍。这一发现可应用于其他昆虫。
