Berger G M
S Afr Med J. 1978 Oct 21;54(17):693-7.
Evidence is presented that high-density lipoprotein (HDL) promotes the efflux of cholesterol from cells in vitro, and may thus play an important role in the transport of cholesterol from non-hepatic tissues to the liver for excretion. Hypothetical schemes are presented whereby this may be achieved in vivo. This putative function of HDL may be of particular importance in situations in which the capacity of cells to limit the uptake of cholesterol is exceeded, and may therefore constitute the basis for the proposed antiatherogenic action of plasma HDL. However, direct data on the transport function of HDL in intact organisms are meagre. Furthermore, a characteristic of mature atherosclerotic lesions is the extracellular, rather than the intracellular, deposition of cholesterol and other lipids, and the degree to which HDL may influence this process has not been demonstrated. Finally, in inherited disorders which markedly impair the putative HDL transport pathway, atherosclerotic heart disease is generally not an early or severe complication. Despite these caveats, the physiological significance of HDL deserves further attention in order to clarify the uncertainties enumerated above. The clinical application of plasma HDL assay is limited at present to excluding the clinically non-deleterious condition of hyperalpha (HDL)-lipoproteinaemia in patients suffering from familial hypercholesterolaemia.
有证据表明，高密度脂蛋白（HDL）在体外可促进胆固醇从细胞中流出，因此可能在将胆固醇从非肝脏组织转运至肝脏以进行排泄的过程中发挥重要作用。文中提出了一些假说方案，说明这一过程在体内可能是如何实现的。HDL的这一假定功能在细胞限制胆固醇摄取能力被超越的情况下可能尤为重要，因此可能构成血浆HDL拟抗动脉粥样硬化作用的基础。然而，关于HDL在完整生物体中的转运功能的直接数据却很少。此外，成熟动脉粥样硬化病变的一个特征是胆固醇和其他脂质在细胞外而非细胞内沉积，且HDL对这一过程的影响程度尚未得到证实。最后，在明显损害假定的HDL转运途径的遗传性疾病中，动脉粥样硬化性心脏病通常不是早期或严重的并发症。尽管存在这些警告，但HDL的生理意义仍值得进一步关注，以澄清上述不确定性。目前，血浆HDL检测的临床应用仅限于排除家族性高胆固醇血症患者临床上无害的高α（HDL）脂蛋白血症情况。
