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Effect of chronic glucagon administration on lipoprotein composition in normally fed, fasted and cholesterol‐fed rats
Author(s) -
Guettet Catherine,
Rostaqui Najmuddin,
Mathe Denis,
Lecuyer Bernard,
Navarro Nicole,
Jacotot Bernard
Publication year - 1991
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02536072
Subject(s) - medicine , endocrinology , very low density lipoprotein , cholesterol , glucagon , lipidology , chemistry , lipoprotein , chylomicron , catabolism , high density lipoprotein , clinical chemistry , metabolism , biology , insulin
Abstract Male adult Wistar rats received daily (at 9 a.m. and 5 p.m.) 10 μg of zinc‐protamine glucagon by subcutaneous injection for 8 days. Plasma cholesterol levels were decreased by 36% in fed rats, 33% in cholesterol‐fed rats and by 55% in fasted rats. Lipoproteins were separated into 22 fractions by ultracentrifugation using a density gradient. Glucagon administration decreased the cholesterol content in all lipoproteins except low density lipoprotein (LDL 1 ) (1.006–1.040) and very low density lipoprotein (VLDL) from cholesterol‐fed rats. The main decrease (−57 to −81%) was observed in 1.050–1.100 g/mL lipoproteins (LDL 2 and HDL 2 ), which contained a large amount of apo E, while HDL 3 cholesterol was not affected. Triacylglycerol levels were decreased only in chylomicrons and VLDL (−70%) of fed and cholesterol‐fed rats, while plasma and lipoprotein triacylglycerol levels were not changed in fasted rats treated with glucagon. In normally fed rats glucagon administration increased by 42% the fractional catabolic rate of [ 125 I]HDL 2 while the absolute catabolic rate appeared to be unchanged. Glucagon seems to be a potent hypolipidemic agent affecting mainly the apo E‐rich lipoproteins. Its chronic administration limits lipoprotein accumulation which occurs upon cholesterol feeding.