Characterization of a functional AT1A angiotensin receptor in pancreatoma AR4-2J cells.
Functional angiotensin receptors were characterized in the rat pancreatic acinar cell line AR4-2J. Angiotensin II stimulated a dose-dependent release of amylase and production of inositol phosphates. Results of high-performance liquid chromatography separation of inositol phosphates indicated that angiotensin stimulated the rapid accumulation of inositol 1,3,4-trisphosphate. Angiotensin II and angiotensin III were at least an order of magnitude more potent than angiotensin I in the stimulation of amylase release. The angiotensin II-stimulated amylase release was blocked by losartan, a selective AT1 angiotensin antagonist. The selective AT2 angiotensin receptor ligands CGP42112 did not alter angiotensin II-stimulated amylase released. However, CGP42112 stimulated amylase release at micromolar concentrations with a potency similar to angiotensin I. Analysis of mRNA expression by reverse transcription polymerase chain reaction suggested that AT1A was the predominant type-I angiotensin receptor expressed in the AR4-2J cells.
Cheung
W T
WT
Department of Biochemistry, Faculty of Medicine, The Chinese University of Hong Kong. wtcheung@cuhk.edu.hk
Yeung
S Y
SY
Yiu
A K
AK
Ip
T M
TM
Wan
D C
DC
Luk
S K
SK
Ho
W K
WK
D000681:Amylases / Q000378:metabolism; D000804:Angiotensin II / Q000494:pharmacology; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D007295:Inositol Phosphates / Q000096:biosynthesis; D007700:Kinetics; D019808:Losartan / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D044140:Receptor, Angiotensin, Type 1; D011945:Receptors, Angiotensin / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D057911:Angiotensin Receptor Antagonists; D017931:DNA Primers; D007295:Inositol Phosphates; D009842:Oligopeptides; D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; D011945:Receptors, Angiotensin; D000804:Angiotensin II; C060894:CGP 42112A; C058097:inositol 1,3,4-trisphosphate; D000681:Amylases; D019808:Losartan