Expression of heat shock proteins in tissues from young pigs exposed to transport stress

The objective of the present study was to investigate the role of heat shock proteins (Hsps) as potential stress response marker in several organs of transported pigs. Constitutive (Hsp90, Hsp70 and Hsp27) and inducible (Hsp72 and Hsp86) Hsps expressed in skeletal muscle, heart, liver and kidney of transported young pigs were investigated. The study comprised 13 German Landrace line pigs (mean weight, approx. 35 +/- 1 kg). Eight animals (n = 8) were transported for a period of 6 h, whereas the control group (n = 5) was kept under normal housing conditions. Identification of Hsps was performed by immunoblot using porcine specific antibodies. Although the 5 Hsps were regularly detected in all porcine tissues, no clear up-regulation could be observed due to transportation. Densitometrical analysis of the immunoblots revealed an unexpected result. Every tissue had a significant reduction of at least 2 Hsp members: Kidney (Hsp90 and Hsp70), M. longissimus dorsi (Hsp90 and Hsp72) and M. gluteus maximus superficialis (Hsp90 and Hsp86), liver (Hsp90, Hsp86 and Hsp27). The heart was most affected, all Hsps were significantly reduced by 26% to 41% after 6 h of transportation. The regular reduction of the large Hsp90 and Hsp86 in nearly all tissues examined point to a new and critical role these Hsps might have in counteracting short-term stress reactions. The fast reduction of Hsps in fatal organs such as heart and kidney may have a relation to organ failure. Hsp90 level may therefore serve as a potential marker for the stress pigs are suffering during transportation.