High density lipoprotein cholesterol in haemorrhagic hyperlipidaemia in rabbits

The effects of repeated bleeding (15 ml/day/kg b.wt. on 3 consecutive days) on plasma lipids, especially on high density lipoprotein (HDL)-cholesterol were studied in rabbits. As a result of the bleeding, plasma triglycerides (TG) increased from a mean of 0.61 (SD range 0.34-1.09) mmol/l to 2.86 (1.16-7.12) mmol/l (P less than 0.02). Plasma total cholesterol (TC) increased from 1.4 +/- 0.5 (SD) mmol/l to 2.0 +/- 0.5 mmol/l. The concentration of HDL-cholesterol, however, decreased from 0.72 +/- 0.16 mmol/l to 0.48 +/- 0.23 mmol/l (P less than 0.02). The HDL-cholesterol/TC ratio decreased from 0.57 +/- 0.17 to 0.29 +/- 0.15 (P less than 0.05). In connection with the haemorrhagic hyperlipidaemia a negative correlation (P less than 0.01) appeared between plasma TG and HDL-cholesterol. It is concluded that hypoxia, being the primary cause of haemorrhagic hyperlipidaemia, may be one factor regulating HDL-cholesterol concentrations and thereby possibly the development of atherosclerosis.