[Effect of substance P on expression of beta1-adrenergic receptor in cultured rat cardiomyocytes].
OBJECTIVE
To investigate the effect of substance P (SP) on expression of beta1-adrenergic receptor (beta1-AR) in cultured neonatal rat cardiomyocytes.


METHODS
Cardiomyocytes were obtained from 1-3 days old Sprague-Dawley (SD) rats and cultured for 72 hours. Six wells of the cultured cells were divided into two groups (n=3 in each group): control group and SP group (incubated with 10(-7) mol/L of SP). Immunocytochemistry was used to detect the expression of beta1-AR in cultured rat cardiomyocytes. Fifteen wells of the cultured cells were divided into five groups (n=3 in each group): control group and four SP groups (incubated with 10(-9), 10 (-8), 10(-7), 10(-6) mol/L of SP respectively). Quantitative analysis of the expression of beta1-AR in cultured neonatal rat cardiomyocytes of all the groups was performed using flow cytometry.


RESULTS
The results of immunocytochemistry showed that the expression of beta1-AR in cardiomyocytes in SP group was lower than that in control group (positive unit: 179.16+/-48.18 vs. 205.79+/-117.42, average light density: 128.26+/-22.72 vs. 157.35+/-33.11, both P<0.05). The results of flow cytometry showed that significantly lower levels of expression of beta1-AR were observed in the groups treated with SP in the concentrations ranging from 10 (-8) mol/L to 10 (-6) mol/L (151.85+/-4.63,135.00+/-6.84,121.41+/-5.22 vs. 161.35+/-3.09,all P<0.05).


CONCLUSIONS
SP could down-regulate the expression of beta1-AR in cultured rat cardiomyocytes in vitro.
Ma
Yan-Xia
YX
Department of Anesthesiology, Second Hospital of Shanxi Medical University, Taiyuan 030001, Shanxi, China.
Guo
Zheng
Z
D000818:Animals; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects; D005260:Female; D008297:Male; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018342:Receptors, Adrenergic, beta-1 / Q000378:metabolism*; D013373:Substance P / Q000494:pharmacology*
D018342:Receptors, Adrenergic, beta-1; D013373:Substance P