Early changes of alpha B-crystallin mRNA in rat skeletal muscle to mechanical tension and denervation.

alpha B-Crystallin specifically decreases in atrophied rat soleus muscle with hindlimb suspension (HS). alpha B-Crystallin cDNA was cloned from rat heart cDNA library using oligonucleotide probe, and its complete coding and partial non-coding regions were sequenced. Northern blot analysis revealed that alpha B-crystallin mRNA in slow muscle decreases at 36 hour after HS but recovered at 24 hour after HS stopped. Denervation decreased the expression of alpha B-crystallin mRNA in slow muscle but increased it in fast muscles, which hardly expressed in normal condition. Passive tension increased the expression of alpha B-crystallin mRNA in both muscle types. Based upon these Northern blot analysis of alpha B-crystallin, nerve innervation and external load on muscle are essential regulatory factors on the expression of the mRNA of alpha B-crystallin in rat skeletal muscle.