摘要
【目的】p94,又称calpain_3a是主要在骨骼肌中表达的一种钙激活蛋白酶,与骨骼肌的生长和肉的嫩度有很强的相关性。生长抑素(SS)通过抑制垂体生长激素的分泌而影响机体的生长性能,SS同时也能抑制钙蛋白酶的表达和活性。半胱胺(CS)能耗竭机体内的SS,因而可能影响肌肉的嫩度和骨骼肌钙蛋白酶的表达。【方法】为验证以上假说,本试验选取60头健康无病,体重一致(15±1)kg的3月龄育肥山羊,随机分成两组(组Ⅰ与组Ⅱ),组Ⅰ饲喂基础日粮,组Ⅱ饲喂添加900mg·kg-1CS的基础日粮。60d后宰杀采集血液、背最长肌和半腱肌。分别测定血清中三碘甲腺原氨酸和甲状腺素浓度、肌肉剪切力和肌肉p94 mRNA的表达。【结果】日粮添加半胱胺显著促进育肥山羊的生长(P<0.05),显著改善半腱肌的嫩度(P<0.05),提高半腱肌中p94 mRNA的表达(P<0.05),但对血清中三碘甲腺原氨酸(T3)和甲状腺素(T4)的浓度以及背最长肌的嫩度均没有显著影响(P>0.05)。【结论】半胱胺明显提高山羊增重,并可能通过上调半腱肌p94 mRNA的表达而显著改善山羊半腱肌的嫩度。
[Objective] The objective was to study p94 or calpain3_a, a Ca^2＋-dependent protease expressed mainly in skeletal muscle, which is highly correlated with muscle growth and meat tenderness. Somatostatin （SS） is the major inhibitory factor for growth hormone secretion and has also been reported to attenuate the expression and activity of calpains, Cysteamine （CS） can deplete the endogenous SS and thus is expected to have an influence on animal growth and meat tenderness. [Method] To test this hypothesis, 60 healthy fattening goats with average body weights of （15± 1） kg were employed and evenly divided into two groups （group Ⅰ and Ⅱ ） at random. Group Ⅰ was fed with a basal diet and group Ⅱ with basal diet supplemented with 900 mg·kg^-1 CS. Goats were slaughtered after 60 days. Blood was collected to detect the serum levels of T3 and T4, the longissimus dorsi and semitendinosus muscles were sampled to investigate the shear force and the expression of p94 mRNA. [Result] The results showed that dietary supplementation of CS significantly accelerated body weight gain （P 〈0.05） and improved the tenderness of semitendinosus muscle of fattening goats （P 〈0.05）, accompanied with increased expression of p94 mRNA （P 〈0.05）, However, the serum levels of T3 and T4 and the tenderness of the longissimus dorsi were not affected by CS treatment （P 〉0,05）. [Conclusion] The results indicate that dietary supplementation of cysteamine can accelerate the growth of goats and meliorate the tenderness of semitendinosus muscle through the up regulation of p94 mRNA expression in the muscle.
出处
《中国农业科学》
CAS
CSCD
北大核心
2007年第5期1010-1016,共7页
Scientia Agricultura Sinica
基金
"十五"国家科技攻关项目(2001BA514A31-02)
