鸡前、后背阔肌去神经后对辣根过氧化物酶(HRP)的胞纳作用

本文报道了用辣根过氧化物酶(HRP)作为大分子标记物,以组织化学和生物化学方法观察了鸡前后背阔肌在去神经后的胞纳现象。结果表明,在去神经后发生肥大的前背阔肌和去神经后发生萎缩的后背阔肌同样都出现胞纳的明显增加。组织化学所观察的结果表明,浸泡在含 HRP 的任氏液中的有完整神经支配的前、后背阔肌只有极少数的肌纤维摄取 HRP,而在去神经的前、后背阔肌中则有不少的肌纤维内部出现 HRP 染色反应。这种反应在有的纤维表现为弥散性染色,有的表现为浓的 HRP 反应颗粒。生物化学的结果显示,去神经后的前、后背阔肌中 HRP 的相对含量分别比有神经支配的对照肌肉明显地增多54%和87%,我们在鸡前背阔肌用组织化学和生物化学所得的实验结果与 Thesleff 等人提出的关于肌肉萎缩机制的假设显然不符。本工作证实了肌肉的胞纳作用的增加并不一定最终导致肌纤维的变性和萎缩。

ENDOCYTOSIS OF HORSERADISH PEROXIDASE(HRP)IN ANTERIOR AND POSTERIOR LATISSIMUS DORSI OF THE CHICK FOLLOWING DENERVATION

Endocytosis of horseradish peroxidase(HRP)was studied in surgically dener-vated and innervated anterior latissimus dorsi(ALD)and posterior latissimus dorsi(PLD)of the chick by a combination of histochemical and biochemical techni-ques.The results indicated that a marked enhancement of endocytosis occurred indenervated hypertrophic ALD as well as in denervated atrophic PLD.Histochemical examination showed that a population of denervated musclefibers contained HRP bodies in various segments of the muscle fibers.Such HRP-containing bodies were almost not observed in innervated muscle fibers.In both denervated and innervated muscle fibers were found to have somediffuse peroxidase staining reaction or some positive staining for HRP-containingbodies.Biochemical experiment showed that HRP uptake in denervated ALD and PLDwere about 54% and 87% higher than in innervated ALD and PLD respectively.The results of the above experiment suggest that endocytosis enhancementdoes not necessarily result in degeneration and atrophy of muscle fibers.