title: Use of positron emission tomography to study AT1 receptor regulation in vivo.
abstract: Increased sodium intake and enhanced sodium sensitivity are implicated in the pathogenesis of hypertension and in the control of a major regulator of BP, the type 1 angiotensin receptor (AT(1) receptor). An in vivo technique to study changes of renal AT(1) receptors by dietary sodium was developed that uses positron emission tomography (PET). PET revealed that renal cortical AT(1) receptor binding was increased in sodium-loaded compared with sodium-deprived dogs, which correlated with ex vivo estimations of AT(1) receptor numbers. Plasma renin activity, angiotensin II, and aldosterone were inversely related to changes in AT(1) receptor binding. These results demonstrate, for the first time in vivo, that the renal AT(1) receptor is inversely related to the activity of the renin angiotensin system, which may provide a compensatory mechanism to prevent inappropriate fluctuations in arterial BP. The ability to measure AT(1) receptor binding in vivo has potential significance for clinical studies of AT(1) receptors, because PET is a noninvasive imaging technique that is readily applicable in humans.
authors: Division of Nuclear Medicine, The Russel H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland.
authors: Zsolt
authors: Z
authors: Szabo
authors: Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Washington State University, Pullman, Washington, and Department of Neuroscience, Oregon Regional Primate Research Center, Oregon Health Sciences University, Beaverton, Oregon.
authors: Robert C
authors: RC
authors: Speth
authors: Division of Comparative Medicine, The Johns Hopkins University, Baltimore, Maryland.
authors: P Randy
authors: PR
authors: Brown
authors: Division of Nuclear Medicine, The Russel H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland.
authors: Levente
authors: L
authors: Kerenyi
authors: Chang Gung Memorial Hospital, Department of Nuclear Medicine, Taipei, Taiwan.
authors: Pan Fu
authors: PF
authors: Kao
authors: Division of Nuclear Medicine, The Russel H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland.
authors: William B
authors: WB
authors: Mathews
authors: Division of Nuclear Medicine, The Russel H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland.
authors: Hayden T
authors: HT
authors: Ravert
authors: Division of Nuclear Medicine, The Russel H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland.
authors: John
authors: J
authors: Hilton
authors: Division of Nuclear Medicine, The Russel H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland.
authors: Paige
authors: P
authors: Rauseo
authors: Division of Nuclear Medicine, The Russel H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland.
authors: Robert F
authors: RF
authors: Dannals
authors: Division of Nephrology and Hypertension, Georgetown University, Washington, DC.
authors: Wei
authors: W
authors: Zheng
authors: Division of Nephrology and Hypertension, Georgetown University, Washington, DC.
authors: Sunghou
authors: S
authors: Lee
authors: Division of Nephrology and Hypertension, Georgetown University, Washington, DC.
authors: Kathryn
authors: K
authors: Sandberg
mesh_terms: D000450:Aldosterone / Q000097:blood; D000804:Angiotensin II / Q000037:antagonists & inhibitors / Q000097:blood; D047228:Angiotensin II Type 1 Receptor Blockers; D057912:Angiotensin II Type 2 Receptor Blockers; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D004285:Dogs; D007093:Imidazoles / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin / Q000378:metabolism*; D012083:Renin / Q000097:blood; D012982:Sodium, Dietary / Q000494:pharmacology; D014055:Tomography, Emission-Computed
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D057912:Angiotensin II Type 2 Receptor Blockers; D057911:Angiotensin Receptor Antagonists; D007093:Imidazoles; D011725:Pyridines; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011945:Receptors, Angiotensin; D012982:Sodium, Dietary; D000804:Angiotensin II; C099071:L 159884; D000450:Aldosterone; D012083:Renin