Excited oxygen species, pyridine nucleotides and calcium transport

PROSTAGLANDINS

EXCITED CADENAS,

OXYGEN

SPECIES,

E., SIES,

PYRIOINE

H., GRAF,

NUCLEOTIOES

P. and #EFERS,

Institut fiir Physiologische Chemie bfloorenstra9e,5, D-4000 Dijsseldorf.

AND CALCIUM

TRANSPORT

H.

I, Universitzt West Germany.

Dtisseldorf,

The formation of excited oxygen snecies such as sinqlet molecular oxygen can be followed by low-level chemiluminescence in intact cells and organs. During reduction of prostaglandin G2 to H there is a burst of photoemission consistent with the dismutation reac z.ion 2 PGG2 2 PGH2 + IO2 (1). Low-level chemiluminescence can further be detected during redox cycling (2,3). The alpha-agonist, phenylephrine , was recently found to modulate the level of photoemission (4). The oxidation of pyridine nucleotides, notably NADPH, by hydroperoxides and 2+ during cytochrome P-450-dependent oxidations was shown to lead to Ca release from the hepatocyte (5) in a fashion similar to that of alphaagonists. The potential relationships between excited oxygen species, pyridine nucleotide oxidation and ion transport will be discussecl.

(1) E. Cadenas, H. Sies, !J. Nastainczyk & V. Ullrich Seyler's , Z. Physiol. Chem. 364, 519-528. (2) H. b!efers & H. SIES (3) E. Cadenas, 147-150.

(1983),

R. Brigelius

(4) H. b+!efers & H. Sies, (5) H. Sies, P. Graf 78, 3358-3362.

Arch.

& H. Sies

(1983),

Hoppe-

Biochem.

Biophys.

224,

in press.

(19X3),

Biochem.

Pharmacol.

32,

unpublished.

.!IJ.M.

SUPPLEMENT TO VOL. 27

Estrela

(1981)

Proc.

Natl.

Acad.

Sci.

USA,