TY - JOUR
T1 - Properties of Prostaglandin Synthetase of Rabbit Kidney Medulla
AU - SCHWARTZMAN, Michal
AU - GAFNI, Yedidya
AU - RAZ, Amiram
PY - 1976/5
Y1 - 1976/5
N2 - The formation in vitro of prostaglandins E2, D2 and F2α from arachidonic acid by rabbit kidney medulla homogenate or microsomal fraction is markedly affected by the composition of the incubation medium employed. Optimal biosynthesis is obtained in 0.1 M potassium phosphate buffer, with the optimum pH being 8.0–8.8. Under these conditions prostaglandin formation is linear up to arachidonic acid concentration of 30 μM. The initial rate of formation of prostaglandin E2+ prostaglandin D2 is 3–4 times higher than that of prostaglandin F2α. Reduced glutathione (1 mM) did not affect the biosynthesis by medulla homogenate and produced only small stimulation of the biosynthesis by microsomal powder. Hydroquinone produced a small stimulation at a low concentration of 0.005 mM, and a strong inhibition at concentrations of 0.1 mM or higher. Addition of bovine serum albumin (0.1%) reduced the microsomal biosynthesis of prostaglandins by approximately 80%. Addition of boiled homogenate or boiled 140000 ×g supernatant produced small stimulation of microsomal biosynthesis while 140000 ×g supernatant (not boiled) caused small inhibition which was not dose‐related. It appears that rabbit kidney prostaglandin‐synthetase converts arachidonic acid to prostaglandins E2 and F2α in comparable amounts, without apparent need for a cytoplasmic soluble cofactor or specific reducing agents.
AB - The formation in vitro of prostaglandins E2, D2 and F2α from arachidonic acid by rabbit kidney medulla homogenate or microsomal fraction is markedly affected by the composition of the incubation medium employed. Optimal biosynthesis is obtained in 0.1 M potassium phosphate buffer, with the optimum pH being 8.0–8.8. Under these conditions prostaglandin formation is linear up to arachidonic acid concentration of 30 μM. The initial rate of formation of prostaglandin E2+ prostaglandin D2 is 3–4 times higher than that of prostaglandin F2α. Reduced glutathione (1 mM) did not affect the biosynthesis by medulla homogenate and produced only small stimulation of the biosynthesis by microsomal powder. Hydroquinone produced a small stimulation at a low concentration of 0.005 mM, and a strong inhibition at concentrations of 0.1 mM or higher. Addition of bovine serum albumin (0.1%) reduced the microsomal biosynthesis of prostaglandins by approximately 80%. Addition of boiled homogenate or boiled 140000 ×g supernatant produced small stimulation of microsomal biosynthesis while 140000 ×g supernatant (not boiled) caused small inhibition which was not dose‐related. It appears that rabbit kidney prostaglandin‐synthetase converts arachidonic acid to prostaglandins E2 and F2α in comparable amounts, without apparent need for a cytoplasmic soluble cofactor or specific reducing agents.
UR - http://www.scopus.com/inward/record.url?scp=0017125943&partnerID=8YFLogxK
U2 - 10.1111/j.1432-1033.1976.tb10332.x
DO - 10.1111/j.1432-1033.1976.tb10332.x
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C2 - 6277
AN - SCOPUS:0017125943
SN - 0014-2956
VL - 64
SP - 527
EP - 534
JO - European Journal of Biochemistry
JF - European Journal of Biochemistry
IS - 2
ER -