猪脂肪沉积的品系差异及其cAMP的调控作用

THE FAT DEPOSITION AND ITS CYCLIC AMP REGULATION OF DIFFERENT LANDRACE STRAINS

体重、健康状况相近的８月龄混系和丹系长白肥育猪１６头，空腹采血测定ｃＡＭＰ、胰岛素、激素敏感脂酶（ＨＳＬ）、游离脂肪酸（ＦＦＡ）和甘油三酯；屠宰后测定胴体指标，并采背部脂肪和肝脏组织，分析了ｃＡＭＰ和腺苷酸环化酶（ＡＣ）活性以及脂肪组织中脂肪酸组成．结果表明，与混系相比，丹系瘦肉率、眼肌面积和后腿比分别高９．４４％（Ｐ＜０．０１）、９．６７％和４．００％，背膘厚、脂肪率和板油比分别低７．９７％、１８．１０％（Ｐ＜０．０５）和１４．２５％。血浆ｃＡＭＰ、ＨＳＬ和ＦＦＡ分别比混系高３２．８５％（Ｐ＜０．０５）、７．４１％和１２３．４１％；甘油三酯和胰岛素则分别低１２．２３％和１８．０６％．丹系脂肪组织中总脂，１４碳和１６碳脂肪酸分别高１０．８５％、３９．６６％（Ｐ＜０．０１）和７．３１％，而１８碳脂肪酸则低４．３１％；丹系肝和脂肪组织中ｃＡＭＰ和ＡＣ显著高于混系。结果证明，猪脂肪沉积的品系差异与肝、脂肪组织及血中ｃＡＭＰ的水平有关，脂肪沉积的ｃＡＭＰ调控具有明显的品系差异。

The cyclic AMP, insulin, hormone sensitive lipase(HSL),free fatty acid(FFA)and triglyceride(TG)in blood were measured for 16 eight month-old Danish Lanrace (DL)and Mixed Landrace(ML)with the similar weight and health condition, The carcass traits wore analysed after slaughtered. The cyclic AMP, adenyl cyclase(AC)activity and fatty acid composition were examined in back adipose and liver tissue. The result showed that the-lean meat percentage, eye muscle area and rear leg ratio of DL were 9.44%(P<0.01),9.67%and 4.00% higher; but the lack-fat thickness, fat percentage and leaf lard ratio were 7.97%,18.10%(P<0.05)and 14.25%lower than that of ML respectively. The cAMP, HSL and FFA of DL were 32.85%(P<0.05),7.41%and 23.41%higher; but triglyceride and insulin are 12.23%and 18.06%lower than that of ML. The 14-carbon and 16-carbon fatty acid of DL in adipose tissue were 39.66%(P<0.01) and 7.31%higher; but 18-carbon fatty acid is lower than that of ML, The cyclic AMP and adenyl cyclase activity of DL in liver and adipose tissue were notably higher than that of ML. The result showed also that the difference of pocrine fat deposition was in close relationship with the level of cyclic AMP in liver and adipose tissue and blood, the control of fat deposition by cAMP existed significant strain differences.