The 13C NMR spectra of poly(adenosine diphosphate ribose), ribosyl adenosine 5', 5''-bis(phosphate) and related compounds were analyzed. The structure of the ribose-ribose linkage was determined as alpha-(1'' leads to 2')ribofuranosyl ribofuranoside, from the 13C chemical shifts of methyl-alpha- and methyl-beta-D-ribofuranosides, and from the downfield displacements of 13C NMR signals by glycosidic bond formation.

No abstract

No abstract

Summary. The administration of leucine aminopeptidase purified from human placenta was found to be effective in lowering the blood pressure in rats with experimental hypertension induced by the infusion of angiotensin II or renin.Systemic hypertension is one of the most common chronic diseases; its diagnosis and treatment constitutes one of our greatest medical challenges today. The renin-angiotensin system is an important regulator of blood pressure in normal and hypertensive individuals. The renal enzyme renin, reacting with a substrate present in blood, produces first an inactive decapeptide, angiotensin I; angiotensin I is then converted to the active octapeptide angiotensin II which is the most potent vasoconstrictor hormone. Since the demonstration by Brunner and Gavaras 3 that receptor antagonists of angiotensin II, such as saralasin, and inhibitors of the enzyme responsible for the conversion of angiotensin I to angiotensin II, such as teprotide 4 and captopril 5, reduce blood pressure in severely hypertensive patients, treatment of hypertension by regulating the angiotensin concentration has been the focus of interest. However, these agents have not yet received unequivocal acceptance; it has been reported that these agents cause serious side-effects, such as agranulocytosis and renal failure 6,7. We present here, using animal models, a different method for the treatment of hypertension due to overactivity of the renin-angiotensin system, using leucine aminopeptidase (arylamidase, LAP), which directly destroys angiotensin in the circulation.