Expression of V-1, a novel catecholamine biosynthesis regulatory protein, is enhanced by hypertension in atrial myocytes of Dahl salt-sensitive rats.
V-1 positively controls catecholamine synthetic gene transcription to promote catecholamine production in PC12D cells. In this study, immunohistochemical analysis revealed that in Wistar rats, V-1 immunoreactivity was localized not only in sympathetic axons but also in the cytoplasm of cardiomyocytes, and that the immunoreactivity in atrial myocytes was more intense than that in ventricular myocytes. Western blot analysis also showed that V-1 expression level in the atrium was higher than that in the ventricle of Wistar rat hearts. When Dahl salt-sensitive (DS) rats were fed an 8% NaCl diet after the age of 6 weeks, blood pressure was raised 230mm Hg at 18 weeks. V-1 expression was shown to be increased in the atrial myocytes of these DS rats, but not in the sympathetic axons, when assayed by immunohistochemistry. These results suggest that in normotensive rats, V-1 is preferentially expressed in the cytoplasm of cardiomyocytes in the atrium rather than in the ventricle. It is also suggested that V-1 expression is increased by hypertension in DS rat atrium.
Yamakuni
Tohru
T
Department of Pharmaceutical Molecular Biology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan. yamakuni@mail.pharm.tohoku.ac.jp
Hashimoto
Michio
M
Sakagami
Hiroyuki
H
Yamamoto
Toshifumi
T
Kobayashi
Masumi
M
Fujii
Yoshimi
Y
Yamamoto
Hideko
H
Rohra
Dileep Kumar
DK
Hiwatashi
Yusuke
Y
Honma
Takao
T
Kondo
Hisatake
H
Shido
Osamu
O
Ohizumi
Yasushi
Y
D000818:Animals; D015153:Blotting, Western; D002395:Catecholamines / Q000096:biosynthesis; D003600:Cytosol / Q000378:metabolism; D015870:Gene Expression; D006325:Heart Atria / Q000378:metabolism; D006352:Heart Ventricles / Q000378:metabolism; D006973:Hypertension / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins; D009206:Myocardium / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D020303:Rats, Inbred Dahl; D017208:Rats, Wistar; D012982:Sodium, Dietary / Q000008:administration & dosage
D002395:Catecholamines; D036341:Intercellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D012982:Sodium, Dietary; C065700:myotrophin