Age-related increases in oxidant stress (OS) play a role in regulation of estrogen receptor (ER) expression in the kidneys. In this study, we establish that in vivo 17β-estradiol (E2) replacement can no longer upregulate glomerular ER expression by 21 months of age in female mice (anestrous). We hypothesized that advanced glycation end product (AGE) accumulation, an important source of oxidant ...

The binding of rat liver glucocorticoid.receptor complexes to DNA-cellulose and nuclei has been studied after activation of the complexes by heating. Subsequent exposure to pyridoxal 5'-phosphate or pyridoxal markedly inhibited this binding. In one system 0.75 mM pyridoxal 5'-phosphate or 6.5 mM pyridoxal gave 50% inhibition. Pyridoxamine 5'-phosphate, pyridoxamine, and pyridoxine did not inhib...

Diabetic nephropathy is a major cause of end-stage kidney disease (ESKD) in patients with type 1 and type 2 diabetes throughout the world. In human glomeruli, expansion of diffuse mesangial matrices, exudative lesions and/or segmental nodular sclerosis are pathological features of diabetic nephropathy. There have been many reports on the pathogenesis and treatment of type 2 diabetes using vario...

Chemical modification studies with pyridoxal 5'-phosphate have indicated that lysine(s) appear to be at or near the active site of Escherichia coli glutamine synthetase (Colanduoni, J., and Villafranca, J. J. (1985) J. Biol. Chem. 260, 15042-15050; Whitley, E. J., Jr., and Ginsburg, A. (1978) J. Biol. Chem. 253, 7017-7025). Enzyme samples were prepared that contained approximately 1, approximat...

PURPOSE OF REVIEW Current therapies proven to slow the progression of diabetic nephropathy include blockade of the renin-angiotensin system (RAS) with either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Given our better understanding of the pathophysiology of diabetic nephropathy, newer therapies to treat this condition are slowly emerging. RECENT FINDINGS Animal...

The contents of six vitamin B6 forms, pyridoxine-β-glucoside, and 4-pyridoxic acid in mature milk of 20 Japanese lactating women consuming ordinary Japanese foods were determined by a 4-pyridoxolactone-conversion HPLC method. These compounds were determined with the average recovery rate of 83.9% or more. The average total content of vitamin B6 forms was 1.01 ± 0.32 (µmol/L). Pyridoxal and pyri...

Pyridoxineless mutants of Escherichia coli B which specifically require pyridoxal or pyridoxamine for growth can be divided into classes according to their growth responses in enriched media. Members of the slowest growing class synthesize vitamin B(6) at the fastest rates when starved for pyridoxal in glycerol minimal medium. After 80 min of synthesis at 4 x 10(-10) moles of vitamin B(6) per m...

Dialkylglycine decarboxylase (DGD) is a pyridoxal phosphate dependent enzyme that catalyzes both decarboxylation and transamination in its normal catalytic cycle. DGD uses stereoelectronic effects to control its unusual reaction specificity. X-ray crystallographic structures of DGD suggest that Q52 is important in maintaining the substrate carboxylate in a stereoelectronically activated positio...

nM. Thus, pyridloxal-P is the principal B6 vitaimer in plasma. Durinig pyridoxine stupplemiienitation, mealn plasnma levels of the B6 vitaimers anid pyridoxic acidl increasedl to 655±122 aindl 222±55 nM, respectively. The plasma content of pyridoxal-P aind( pyricloxic acidl increased 6-7-fold anid thatt of pyridoxal, 12-fold, but the pyridloxiine level did niot increase. Isolatedlhepatocytes, 1...

It has now been clearly established that pyridoxal phosphate serves as the coenayme of many transaminases. Several lines of evidence have indicated that the coenzyme acts alternately as acceptor and donar of amino groups, shuttling between the aldehydic (pyridoxal phosphate) and amino (pyridoxamine phosphate) forms (2-11). However, a detailed study of the kinetics of the transaminase reaction w...