Isolation and characterization of the haemolymph lipoproteins of Triatoma infestans.

1. Three lipoproteins differing in hydrated densities were isolated by ultracentrifugal procedures from the haemolymph of adult and fasted Triatoma infestans. 2. They are the high density lipoprotein HDL (d = 1.115-1.152) and the two very high density lipoproteins VHDL-I (d = 1.190-1.231) and VHDL-II (d = 1.245-1.260). HDL was the predominant lipoprotein. 3. The total lipid content expressed as % of lipoprotein weight in HDL, VHDL-I an VHDL-II was 30.1, 7.8 ad 2.9% respectively. Diacylglycerols are the predominant lipids of HDL (38.7%) and VHDL-I (27.0%) but only amount of 6.2% in VHDL-II. 4. Triacylglycerols are minor components (about 6.0%) of all fractions. 5. The phospholipids (phosphatidylethanolamine and phosphatidylcholine), sterols, sterol esters and hydrocarbons were present in all lipoprotein fractions. 6. Phospholipids and hydrocarbons were the most abundant lipids of VHDL-II.