Effects of chronic glucagon administration on rat lipoprotein composition.
Male adult rats of the Wistar strain received daily at 9 a.m. and 5 p.m. 10 micrograms of Zn-protamine glucagon (Novo) for 21 days by subcutaneous injections. Plasma levels of cholesterol, triacylglycerol and phospholipids were decreased by 47, 40 and 21%, respectively. Lipoproteins were separated by sequential ultracentrifugation. Concentrations of cholesterol, phospholipids and proteins were decreased in chylomicrons, VLDL, LDL2 (1.040-1.063 g/ml) and HDL, LDL2 being the most affected by glucagon treatment (-70%). Triacylglycerol levels were decreased only in chylomicrons and VLDL. The relative proportions of cholesterol, triacylglycerol, phospholipids and proteins in lipoproteins were virtually unchanged by glucagon, suggesting a reduced number of some lipoprotein particles in plasma. However, lipoproteins of glucagon-treated rats were depleted in cholesteryl esters, while the proportion of triacylglycerol increased in LDL and HDL. Apo E contents were decreased in plasma, LDL1 (1.006-1.040 g/ml), LDL2 and HDL, whereas apo B100 proportions increased in VLDL and LDL1 in glucagon-treated rats. Glucagon appeared to be a potent hypolipidemic agent affecting mainly the apo-E-rich lipoproteins.
Guettet
C
C
Unité de Recherches sur les dyslipidémies et l'athérosclérose, INSERM U 32, Hôpital H. Mondor, Créteil, France.
Mathé
D
D
Navarro
N
N
Lecuyer
B
B
D000818:Animals; D001053:Apolipoproteins / Q000097:blood; D002784:Cholesterol / Q000097:blood*; D005934:Glucagon / Q000494:pharmacology*; D008074:Lipoproteins / Q000097:blood* / Q000302:isolation & purification; D008297:Male; D010743:Phospholipids / Q000097:blood*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D014280:Triglycerides / Q000097:blood*
D001053:Apolipoproteins; D008074:Lipoproteins; D010743:Phospholipids; D014280:Triglycerides; D005934:Glucagon; D002784:Cholesterol