Doran O, Moule S K, Teye G A, Whittington F M, Hallett K G, Wood J D
Department of Clinical Veterinary, University of Bristol, Langford, UK.
Br J Nutr. 2006 Mar;95(3):609-17. doi: 10.1079/bjn20051526.
A reduced protein diet (RPD) is known to increase the level of intramuscular lipid in pig meat with a smaller effect on the amount of subcutaneous adipose tissue. This might be due to tissue-specific activation of the expression of lipogenic enzymes by the RPD. The present study investigated the effect of a RPD, containing palm kernel oil, soyabean oil or palm oil on the activity and expression of one of the major lipogenic enzymes, stearoyl-CoA desaturase (SCD) and on the level of total lipids and the fatty acid composition of muscle and subcutaneous adipose tissue in pigs. The RPD significantly increased SCD protein expression and activity in muscle but not in subcutaneous adipose tissue. The level of MUFA and total fatty acids in muscle was also elevated when the RPD was fed, with only small changes in subcutaneous adipose tissue. A positive significant correlation between SCD protein expression and total fatty acids in muscle was found. The results suggest that an increase in intramuscular but not subcutaneous adipose tissue fatty acids under the influence of a RPD is related to tissue-specific activation of SCD expression. It is suggested that the SCD isoform spectra in pig subcutaneous adipose tissue and muscle might be different.
已知低蛋白饮食（RPD）会增加猪肉中肌内脂质水平，对皮下脂肪组织量的影响较小。这可能是由于RPD对生脂酶表达的组织特异性激活所致。本研究调查了含棕榈仁油、大豆油或棕榈油的RPD对猪主要生脂酶之一硬脂酰辅酶A去饱和酶（SCD）的活性和表达、总脂质水平以及肌肉和皮下脂肪组织脂肪酸组成的影响。RPD显著增加了肌肉中SCD蛋白的表达和活性，但对皮下脂肪组织没有影响。饲喂RPD时，肌肉中MUFA和总脂肪酸水平也有所升高，皮下脂肪组织仅有微小变化。发现肌肉中SCD蛋白表达与总脂肪酸之间存在显著正相关。结果表明，在RPD影响下，肌内而非皮下脂肪组织脂肪酸的增加与SCD表达的组织特异性激活有关。提示猪皮下脂肪组织和肌肉中的SCD同工型谱可能不同。
