Angiotensin AT1 receptors in Clone 9 rat liver cells: Ca2+ signaling and c-fos expression.
In C9 (Clone 9) liver cells, angiotensin 11 increased the intracellular Ca2+ content, inositol phosphate production and c-fos mRNA expression. Other angiotensins were also active with the order of potency being angiotensin II = angiotensin III >> angiotensin I > angiotensin IV. Losartan, but not PD 123177 (1-(4-amino-3-methyl)-5-diphenylacetyl-4,5,6,7-tetrahydro-1H-imida zo [4,5c]pyridine-6-carboxylic acid), blocked the effects of angiotensin II. Pertussis toxin did not alter these actions of angiotensin II. These data indicate that the effects were mediated through angiotensin AT1 receptors involving pertussis toxin-insensitive G-proteins. Phorbol myristate acetate was also able to increase c-fos mRNA expression. The action of angiotensin II was consistently greater than that of the active phorbol ester. Staurosporine but not genistein inhibited this effect of angiotensin II. Angiotensin II- and phorbol myristate acetate-induced proto-oncogene mRNA expression was attenuated in cells incubated overnight with the active phorbol ester, which suggests a major role of protein kinase C.
García-Sáinz
J A
JA
Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico DF. agarcia@ifcsun1.ifisiol.unam.mx
García-Caballero
A
A
González-Espinosa
C
C
D000804:Angiotensin II / Q000187:drug effects / Q000494:pharmacology*; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002478:Cells, Cultured; D002999:Clone Cells; D004347:Drug Interactions; D015870:Gene Expression / Q000187:drug effects; D007295:Inositol Phosphates / Q000096:biosynthesis; D008099:Liver / Q000166:cytology / Q000502:physiology*; D019808:Losartan / Q000494:pharmacology; D037342:Pertussis Toxin; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D000889:Anti-Arrhythmia Agents; D007295:Inositol Phosphates; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin; D010566:Virulence Factors, Bordetella; D000804:Angiotensin II; D037342:Pertussis Toxin; D019808:Losartan; D002118:Calcium