Effect of gamma-glutamyl carboxylation of renal microsomes on calcium oxalate monohydrate crystal binding in hyperoxaluria.
OBJECTIVE
The gamma-carboxy glutamic acid (gla) containing proteins have been shown recently to have a role in calcium oxalate urolithiasis. Therefore, the effect of carboxylation on calcium oxalate monohydrate (COM) binding was studied in experimental hyperoxaluria.


METHODS
Urolithiasis was induced in experimental rats by oral feeding 1% ethylene glycol (EG). The microsomes were carboxylated in presence of reduced vitamin K and COM binding activity was determined.


RESULTS
Microsomal proteins adsorbed maximally with COM crystals. On carboxylation of the renal microsomal proteins, a significant increase in the COM crystal adsorption by 2.5-fold (p < 0.001) was observed in the hyperoxaluric condition. Further cyboxylated microsomes of EG-treated rats showed significant binding with calcium oxalate.


CONCLUSIONS
This study presents an increased COM adsorption after the carboxylation of renal microsomes of hyperoxaluric rats.
Department of Medical Biochemistry, Dr. ALM Post-Graduate Institute of Basic Medical Sciences, University of Madras, Taramani, India.
N
N
Angayarkanni
R
R
Selvam
D015055:1-Carboxyglutamic Acid / Q000378:metabolism*; D000327:Adsorption; D000818:Animals; D002129:Calcium Oxalate / Q000737:chemistry / Q000378:metabolism*; D003460:Crystallization; D006959:Hyperoxaluria / Q000209:etiology / Q000378:metabolism*; D066298:In Vitro Techniques; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008861:Microsomes / Q000378:metabolism; D011506:Proteins / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014545:Urinary Calculi / Q000209:etiology / Q000378:metabolism
D011506:Proteins; D002129:Calcium Oxalate; D015055:1-Carboxyglutamic Acid