Reperfusion but not acute ischemia in pig small intestine induces transcriptionally mediated heat shock response in situ.
BACKGROUND
Although there is data on the cytoprotective role of heat shock proteins in intestinal ischemia-reperfusion, the effects of ischemia and reperfusion per se on the small intestinal heat shock response have been poorly characterized.


METHODS
Four female pigs were subjected to 60-min ischemia by superior mesenteric artery occlusion followed by 360-min reperfusion. Systemic and local hemodynamics were monitored. Samples from the jejunal mucosa and muscularis were obtained for histology and for time series molecular biologic analyses of heat shock transcription factor 1 (HSF1), hsp70 mRNA and Hsp70 protein.


RESULTS
A 30-min reperfusion of jejunum after a preceding 1-hour ischemia results in a significantly increased DNA-binding activity of HSF1, in a 10-fold increase of hsp70 mRNA in the mucosal and in a 7-fold increase in the muscular layers. Translational activation and accumulation of Hsp70 protein occurs after 60 min of reperfusion in the intestine. Nevertheless, a 60-min ischemia inducing mucosal detachment does not induce the heat shock response at any level analyzed.


CONCLUSIONS
Ischemia alone is insufficient to induce the heat shock response, whereas subsequent reperfusion induces the response via transcriptionally mediated induction of Hsp70 synthesis both in the mucosal and muscular layers.
Oksala
N K J
NK
Department of Surgery, Kuopio University Hospital, Kuopio, Finland.
Kaarniranta
K
K
Tenhunen
J J
JJ
Tiihonen
R
R
Heino
A
A
Sistonen
Lea
L
Paimela
H
H
Alhava
E
E
D000208:Acute Disease; D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics*; D000076249:Heat Shock Transcription Factors; D018869:Heat-Shock Response / Q000502:physiology; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D007583:Jejunum / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D019344:Lactic Acid / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D013552:Swine; D014157:Transcription Factors; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D018840:HSP70 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D012333:RNA, Messenger; D014157:Transcription Factors; D002245:Carbon Dioxide; D019344:Lactic Acid