Ser-Leu-Arg-Arg-atriopeptin III: the major circulating form of atrial peptide

Vasopressin induces a concentration-dependent increase in atriopeptin immunoreactivity in plasma. Rat plasma, rat atrial extract, and synthetic atriopeptin III (APIII) produced parallel displacement curves of iodine-125-labeled APIII binding to specific antiserum. Fractionation of plasma atriopeptin immunoreactivity by reverse-phase high-performance liquid chromatography showed that the major portion consists of two species of low molecular weight peptides in a ratio of 10 to 1. Both peaks exhibited potent vasorelaxant activity, suggesting the presence of the carboxyl terminal Phe-Arg sequence of atriopeptin in each species. Sequence determination of the purified peptides indicated that the major peptide is Ser-Leu-Arg-Arg-APIII and the minor peptide APIII. It appears that the former is the major species of atrial peptide in the rat circulation and that it is the product of selective cleavage of the high molecular weight precursor.     

Chronology for the Aegean Late Bronze Age 1700-1400 B.C

Radiocarbon (carbon-14) data from the Aegean Bronze Age 1700-1400 B.C. show that the Santorini (Thera) eruption must have occurred in the late 17th century B.C. By using carbon-14 dates from the surrounding region, cultural phases, and Bayesian statistical analysis, we established a chronology for the initial Aegean Late Bronze Age cultural phases (Late Minoan IA, IB, and II). This chronology contrasts with conventional archaeological dates and cultural synthesis: stretching out the Late Minoan IA, IB, and II phases by approximately 100 years and requiring reassessment of standard interpretations of associations between the Egyptian and Near Eastern historical dates and phases and those in the Aegean and Cyprus in the mid-second millennium B.C.