Expression of stress proteins in porcine tissues: developmental changes and effect of immunological challenge

Immunoblot procedures were used to evaluate stress protein (SP) expression in developing and suckling piglet and in growing pigs challenged immunologically with bacterial lipopolysaccharide (LPS). The constitutively expressed 70-kDa SP (HSC70) and HSP60 were detected in the whole fetus at 30 d of development and in cardiac and skeletal muscle, liver, and lung at 50, 80, and 109 d. Expression of HSP60 was higher (P < or = .03) postnatally in cardiac and skeletal muscle and in lung, whereas HSC70 expression increased (P < or = .01) only in skeletal muscle. The stress-inducible 70-kDa SP (HSP70) was detected in skeletal muscle samples collected 4 d postnatally in two of the four piglets sampled. However, this SP was not detected in samples collected 18 d postnatally. In the LPS challenge study, HSP70 was detected only in liver and intestinal mucosa, and an unidentified protein of approximately 130 kDa was evident in liver and tissue. Expression of HSP70 in liver was not affected by LPS but doubled (P < or = .01) in the jejunal mucosa. Furthermore, although faintly evident in the mucosa of spiral colon of control pigs, HSP70 was clearly increased (P < = .01) in that of challenged pigs. Liver concentrations of the immunoreactive 130-kda protein were not influenced by LPS. The data presented herein indicate that tissue concentration of specific SP change in vivo with development age and that an immunological challenge increases the concentration of specific SP in some tissues.