title: The circadian rhythm of the N-terminus and C-terminus of the atrial natriuretic factor prohormone.
abstract: Circadian variation in the circulating concentrations of the N-terminal and C-terminal portions of the atrial natriuretic factor prohormone (pro ANF) was evaluated in 8 men, ages 41-47, who have been followed for 19 years with respect to circadian variation in physiological variables including blood pressure and clinical chemistries. The N-terminus of the ANF prohormone contains two peptides consisting of amino acids 1-30 and 31-67 while the C-terminus contains 1 peptide (amino acids 99-126) of this 126 amino acid prohormone which lower blood pressure and have natriuretic properties. To determine if either the N-terminus and/or the C-terminus of the prohormone have a circadian variation in their circulating plasma concentrations these 8 men had blood samples obtained for radiommunoassay every 3 hr during a 24-hr period. Three radiommunoassays which immunologically recognize (1) the whole N-terminus (i.e. amino acids 1-98), (2) the midportion of the N-terminus (amino acids 31-67) and (3) the C-terminus (amino acids 99-126) of the ANF prohormone were utilized. The whole N-terminus, the midportion of the N-terminus which circulates after being proteolytically cleaved from the rest of the N-terminus, and the C-terminus each had a peak circulating concentration between 0400 and 0700 which were significantly (P less than 0.001) higher than their concentrations at any other time throughout the 24-hr period.(ABSTRACT TRUNCATED AT 250 WORDS)
authors: Department of Internal Medicine, University of South Florida for Health Sciences, Tampa.
authors: D L
authors: DL
authors: Vesely
authors: E L
authors: EL
authors: Kanabrocki
authors: R B
authors: RB
authors: Sothern
authors: L E
authors: LE
authors: Scheving
authors: T H
authors: TH
authors: Tsai
authors: J
authors: J
authors: Greco
authors: D L
authors: DL
authors: Bushell
authors: E
authors: E
authors: Kaplan
authors: J
authors: J
authors: Rumbyrt
authors: R P
authors: RP
authors: Sturtevant
mesh_terms: D000328:Adult; D009320:Atrial Natriuretic Factor / Q000097:blood*; D001794:Blood Pressure / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood; D011498:Protein Precursors / Q000097:blood*
chemical_list: D010446:Peptide Fragments; D011498:Protein Precursors; C054548:atrial natriuretic factor prohormone (31-67); C055659:atrial natriuretic factor prohormone (1-98); D009320:Atrial Natriuretic Factor