重组牛生长激素（rbST）可增加早期断奶犊牛半腱肌中快速糖酵解型肌纤维的大小和比例。

Recombinant bovine somatotropin (rbST) increases size and proportion of fast-glycolytic muscle fibers in semitendinosus muscle of creep-fed steers.

作者信息

Vann R C, Althen T G, Solomon M B, Eastridge J S, Paroczay E W, Veenhuizen J J

机构信息

Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State 39762, USA.

出版信息

J Anim Sci. 2001 Jan;79(1):108-14. doi: 10.2527/2001.791108x.

DOI:10.2527/2001.791108x

PMID:11204689

Abstract

The objective of this study was to determine the effect of recombinant bovine somatotropin (rbST) on muscle fiber histology and histochemistry in creep-fed beef steers. Crossbred steer calves were assigned to one of two treatment groups: control (sham-injected; n = 12) or rbST-injected (0.09 mg x kg(-1) x d(-1); n = 12). Calves were injected every 14 d starting at d 28 of age until weaning at 205 d of age. Biopsies of the semitendinosus muscle were performed on d 100, and slaughter samples of semitendinosus muscle were collected for muscle fiber analyses on d 206. The rbST-treated calves had larger (P = 0.045) fast-twitch-glycolytic (FG) fibers [2,564 +/- 10 vs 2,351 +/- 11 microm2 cross-sectional area, respectively] than controls. No differences (P = 0.36) between rbST-treated and control steers in cross-sectional area were detected for slow-twitch-oxidative (SO) [1,192 +/- 20 vs 1,148 +/- 22 microm2, respectively] or fast-twitch-oxidative-glycolytic (FOG) fibers [1,484 +/- 35 vs 1,403 +/- 38 microm2, respectively]. The percentage distribution for FOG fibers was greater for control calves than for the rbST-treated calves (38.4 vs 34.9 +/- 0.1%, respectively; P = 0.014), whereas the percentage distribution for FG fibers was greater in the rbST-treated calves than for control calves (53.5 vs 48.4 +/- 0.2%, respectively; P = 0.03). The percentage distribution for SO fibers tended to be greater for the control calves than for the rbST-treated calves (13.1 vs 11.7 +/- 0.1%, respectively; P = 0.07). The percentage of FG fibers increased with age (45.4 vs 56.6 +/- 0.8%, respectively; P = 0.001), whereas the percentage distribution of SO (14.3 vs 10.5 +/- 0.5%, respectively) and FOG fibers (40.3 vs 32.9 +/- 0.7%, respectively) decreased (P = 0.001) from d 100 to d 206. The increased longissimus muscle area and dissectable lean tissue in rbST-treated calves are associated with a greater percentage of FG fibers, which possess larger cross-sectional areas than the other fibers.

摘要

本研究的目的是确定重组牛生长激素（rbST）对犊牛育肥期肉牛肌肉纤维组织学和组织化学的影响。杂种公牛犊被分为两个处理组之一：对照组（假注射；n = 12）或注射rbST组（0.09 mg x kg(-1) x d(-1)；n = 12）。从28日龄开始，每隔14天给犊牛注射一次，直至205日龄断奶。在第100天对半腱肌进行活检，并在第206天采集半腱肌屠宰样本用于肌肉纤维分析。与对照组相比，注射rbST的犊牛具有更大（P = 0.045）的快肌糖酵解型（FG）纤维[横截面积分别为2,564 +/- 10与2,351 +/- 11平方微米]。在慢肌氧化型（SO）[分别为1,192 +/- 20与1,148 +/- 22平方微米]或快肌氧化糖酵解型（FOG）纤维[分别为1,484 +/- 35与1,403 +/- 38平方微米]的横截面积方面，注射rbST的犊牛与对照组之间未检测到差异（P = 0.36）。对照组犊牛的FOG纤维百分比分布高于注射rbST的犊牛（分别为38.4%与34.9 +/- 0.1%；P = 0.014），而注射rbST的犊牛的FG纤维百分比分布高于对照组犊牛（分别为53.5%与48.4 +/- 0.2%；P = 0.03）。对照组犊牛的SO纤维百分比分布倾向于高于注射rbST的犊牛（分别为13.1%与11.7 +/- 0.1%；P = 0.07）。从第100天到第206天，FG纤维的百分比增加（分别为45.4%与56.6 +/- 0.8%；P = 0.001），而SO纤维（分别为14.3%与10.5 +/- 0.5%）和FOG纤维（分别为40.3%与32.9 +/- 0.7%）的百分比分布下降（P = 0.001）。注射rbST的犊牛背最长肌面积和可分割瘦肉组织增加与FG纤维百分比更高有关，FG纤维的横截面积比其他纤维更大。