[Parathyroid hormone 1-34 induce cardiac myocytes hypertrophy via extracellular regulated protein kinase 1/2 pathway].
OBJECTIVE
To investigate the role of mitogen activated protein kinase kinase 1 (MAPKK, MEK1) and regulated kinase1/2 (ERK1/2) on cardiac hypertrophy induced by rat parathyroid hormone1-34 (rPTH1-34).


METHODS
Neonatal rat cardiomyocytes was treated with or without 10(-7) mol/L rPTH1-34 in the absence or presence 2 x 10(-5) mol/L PD98059, a MEK1 inhibitor. Cellular diameter was measured by Motic Images Advanced 3.0 software and the synthetic rate of protein in cardiac myocytes was detected by 3H-leucine incorporation, mRNA expression of atrial natriuretic peptide (ANP) was measured by RT-PCR and protein expression of ERK1/2 and p-ERK1/2 was measured by Western blot.


RESULTS
rPTH1-34 (10(-7) mol/L) significantly increase cellular diameter (+13.6 microm), 3H-leucine incorporation (+898 cpm/well), ANP mRNA expression (+73.9%), and p-ERK1/2 protein expression (+15%) compared to control cells (all P < 0.05) and these effects could be significantly attenuated by PD98059: cellular diameter (-7.1 microm), 3H-leucin e incorporation (-644 cpm/well), ANP mRNA expression (-52.2%), and protein expression of p-ERK1/2 (-18%) (all P < 0.05 vs. PTH group). PD98059 did not affect control cells without PTH treatment (all P > 0.05).


CONCLUSIONS
PD98059 attenuates PTH induced cardiac hypertrophy in vitro via inhibiting the expression of ERK1/2 and p-ERK1/2.
Liu
Xiao-gang
XG
Department of Nephrology, Second Hospital, Harbin Medical University, Harbin 150086, China.
An
Hui-xia
HX
Liu
Su-yan
SY
Ren
Ye-ping
YP
Zhang
Wei-bing
WB
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D006332:Cardiomegaly / Q000139:chemically induced / Q000378:metabolism*; D002478:Cells, Cultured; D005419:Flavonoids / Q000494:pharmacology; D005786:Gene Expression Regulation; D048369:MAP Kinase Kinase 1 / Q000378:metabolism*; D048370:MAP Kinase Kinase 2 / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D032383:Myocytes, Cardiac / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000009:adverse effects; D051381:Rats; D017208:Rats, Wistar
D005419:Flavonoids; D010281:Parathyroid Hormone; D009320:Atrial Natriuretic Factor; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one