High glucose concentrations stimulate renal papillary phosphatidylcholine biosynthesis.
The effects of a high glucose concentration (HGC) on renal phosphatidylcholine (PtdCho) biosynthesis were studied. In control rats, HGC increased papillary PtdCho biosynthesis. In chronic diabetic rats, an increase above that induced by diabetes was observed. Such glucose-responsive phospholipid pools were shown to be transient in adult control rats, while in acute diabetic and aged control and chronic diabetic rats they seem to be of slow breakdown or permanent. Deoxyglucose evokes the HGC effect only in the presence of 5 mM glucose. Neomycin, which blocks phospholipase C action, corrected the HGC effect in control and chronic diabetic rats, but not the increase due to diabetes. CDP-choline: 1,2-diacylglycerol cholinephosphotransferase activity was increased by both in vivo and simulated diabetes. Therefore, transient high extracellular glucose levels promote a reversible increase in papillary (32)P-PtdCho, while diabetes causes an irreversible increase resulting in PtdCho accumulation, possibly related to papillary necrosis.
Setton-Avruj
C P
CP
Departamento de Química Biológica, Química Biológica Patológica, Universidad de Buenos Aires, Argentina.
Speziale
E H
EH
Sterin-Speziale
N B
NB
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D003847:Deoxyglucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D007679:Kidney Medulla / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008861:Microsomes / Q000378:metabolism; D009355:Neomycin / Q000494:pharmacology; D010713:Phosphatidylcholines / Q000096:biosynthesis* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D010713:Phosphatidylcholines; D003847:Deoxyglucose; D009355:Neomycin