Mazzoni Maurizio, Soglia Francesca, Petracci Massimiliano, Sirri Federico, Lattanzio Giulia, Clavenzani Paolo
Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, 40064 Ozzano Emilia (B.O.), Italy.
Department of Agricultural and Food Sciences, Alma Mater Studiorum-University of Bologna, 47521 Cesena (F.C.), Italy.
Animals (Basel). 2020 Jun 23;10(6):1081. doi: 10.3390/ani10061081.
The present study aimed to evaluate the muscle fiber metabolism and assess the presence and distribution of both procollagen and collagen type III in pectoralis major muscles affected by white striping (WS), wooden breast (WB), and spaghetti meat (SM), as well as in those with macroscopically normal appearance (NORM). For this purpose, 20 pectoralis major muscles (five per group) were selected from the same flock of fast-growing broilers (Ross 308, males, 45-days-old, 3.0 kg live weight) and were used for histochemical (nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR) and alpha-glycerophosphate dehydrogenase (α-GPD)) and immunohistochemical (procollagen and collagen type III) analyses. When compared to NORM, we found an increased proportion ( < 0.001) of fibers positively stained to NADH-TR in myopathic muscles along with a relevant decrease ( < 0.001) in the percentage of those exhibiting a positive reaction to α-GPD. In addition, an increased proportion of fibers exhibiting a positive reaction to both stainings was observed in SM, in comparison with NORM (14.3 vs. 7.2%; < 0.001). After reacting to NADH-TR, SM exhibited the lowest ( < 0.001) cross-sectional area (CSA) of the fibers (-12% with respect to NORM). On the other hand, after reacting to α-GPD, the CSA of WS was found to be significantly larger (+10%) in comparison with NORM (7480 vs. 6776 µm; < 0.05). A profound modification of the connective tissue architecture involving a different presence and distribution of procollagen and collagen type III was observed. Intriguingly, an altered metabolism and differences in the presence and distribution of procollagen and collagen type III were even observed in pectoralis major muscle classified as NORM.
本研究旨在评估受白纹（WS）、木鸡胸（WB）和意大利面条肉（SM）影响的胸大肌以及外观宏观正常（NORM）的胸大肌中的肌纤维代谢，并评估前胶原和III型胶原的存在及分布情况。为此，从同一群快速生长的肉鸡（罗斯308，雄性，45日龄，活重3.0千克）中选取了20块胸大肌（每组5块），用于组织化学分析（烟酰胺腺嘌呤二核苷酸四唑还原酶（NADH-TR）和α-甘油磷酸脱氢酶（α-GPD））和免疫组织化学分析（前胶原和III型胶原）。与NORM相比，我们发现肌病性肌肉中对NADH-TR呈阳性染色的纤维比例增加（<0.001），而对α-GPD呈阳性反应的纤维百分比显著降低（<0.001）。此外，与NORM相比，SM中对两种染色均呈阳性反应的纤维比例增加（14.3%对7.2%；<0.001）。在与NADH-TR反应后，SM的纤维横截面积（CSA）最小（<0.001）（相对于NORM减少12%）。另一方面，在与α-GPD反应后，发现WS的CSA与NORM相比显著更大（+10%）（7480对6776 µm；<0.05）。观察到结缔组织结构发生了深刻改变，涉及前胶原和III型胶原的不同存在和分布。有趣的是，在分类为NORM的胸大肌中甚至也观察到了代谢改变以及前胶原和III型胶原的存在和分布差异。
