TY - JOUR
TI - Thyroid hormone and cardioprotection: Study of p38 MAPK and JNKs during
ischaemia and at reperfusion in isolated rat heart
AU - Pantos, C
AU - Malliopoulou, V
AU - Paizis, I
AU - Moraitis, P and
AU - Mourouzis, I
AU - Tzeis, S
AU - Karamanoli, E
AU - Cokkinos, DD and
AU - Carageorgiou, H
AU - Varonos, D
AU - Cokkinos, DV
JO - Molecular and Cellular Biochemistry
PY - 2003
VL - 242
TODO - 1-2
SP - 173-180
PB - Springer-Verlag
SN - 0300-8177
TODO - 10.1023/A:1021162417490
TODO - thyroid hormone; ischaemia; p38 MAPK; JNK; rat heart; ischaemic
preconditioning
TODO - It has been recently shown that long-term thyroxine administration
increases the tolerance of the heart to ischaemia. The present study
investigated whether thyroxine induced cardioprotection involves
alterations in the pattern of p38 mitogen activated protein kinase
(p38MAPK) and c-Jun NH2-terminal kinases (JNKs) activation during
ischaemia-reperfusion. L-thyroxine (T4) was administered in Wistar rats
(25 mug/100 g/day, subcutaneously) for 2 weeks (THYR), while normal
animals served as controls (NORM). NORM and THYR isolated rat hearts
were perfused in Langendorff mode and subjected to 10 or 20 min of
zero-flow global ischaemia only and also to 20 min of ischaemia followed
by 10, 20 or 45 min of reperfusion. Postischaemic recovery of left
ventricular developed pressure at 45 min of reperfusion was expressed as
% of the initial value. Activation of p38 MAPK and JNKs was assessed at
the different times of the experimental setting by standard Western
blotting techniques using a dual phospho p38MAPK and phospho JNKs
(p46/p54) antibodies. Activation of p38 MAPK was significantly
attenuated during ischaemia and reperfusion in thyroxine treated hearts
compared to normal hearts. JNKs were found to be activated only during
the reperfusion period. The levels of phospho JNKs were found to be
lower in thyroxine treated hearts as compared to untreated hearts,
though not at a statistically significant level. Postischaemic
functional recovery was higher in THYR as compared to NORM, p < 0.05. In
summary, in hearts pretreated with thyroxine, p38 MAPK was attenuated
during ischaemia and at reperfusion and this was associated with
improved postischaemic recovery of function.
ER -