Type 2 diabetes is a risk factor for Alzheimer's disease and mild cognitive impairment. Folate insufficiency fosters a decline in the sole methyl donor, S-adenosylmethionine, and decreases methylation potential, which is associated with Alzheimer's disease in non-diabetic patients. However, little is known in diabetic patients. We analyzed plasma levels of S-adenosylmethionine, S-adenosylhomocy...

The tissue distribution of S-adenosylmethionine, S-adenosylhomocysteine, methionine adenosyltransferase and S-adenosylhomocysteine hydrolase was explored in the rat. Also the effects of methionine administration on the accumulation of S-adenosylmethionine, S-adenosylhomocysteine and polyamines were studied in rat liver, brain and kidney. The tissue distribution of S-adenosylmethionine, S-adenos...

S-Adenosylmethionine metabolism and its relation to the synthesis and accumulation of polyamines was studied in rat liver under various nutritional conditions, in adrenalectomized or partially hepatectomized animals and after treatment with cortisol, thioacetamide or methylglyoxal bis(guanylhydrazone) {1,1'-[(methylethanediylidine)dinitrilo]diguanidine}. Starvation for 2 days only slightly affe...

The antidepressant properties of S-adenosylmethionine, an endogenous methyl donor, were studied in inpatients who met the DSM-III criteria for major depression. Nine patients given intravenous S-adenosylmethionine and nine given low oral doses of imipramine were compared in a double-blind design for 14 days. The S-adenosylmethionine produced superior results by the end of the first week of trea...

Forty-five minutes after intraperitoneal injection of a single dose (100 milligrams per kilogram) of L-dihydroxyphenylalanine, the concentration of S-adenosylmethionine in rat brain was lowered by 76 percent. As little as 10 milligrams of L-dihydroxyphenylalanine per kilogram decreased content of S-adenosylmethionine in the adrenal medulla by 51 percent, whereas 100 milligrams per kilogram did ...

1. S-Adenosyl-L-methionine decarboxylase (S-adenosyl-L-methionine carboxy-lyase, EC 4.1.1.50) was purified more than 1100-fold from extracts of Saccharomyces cerevisiae by affinity chromatography on columns of Sepharose containing covalently bound methylglyoxal bis(guanylhydrazone) (1,1'[(methylethanediylidene)dinitrilo]diguanidine) [Pegg, (1974) Biochem J. 141, 581-583]. The final preparation ...

Elevated plasma homocysteine concentration is an independent risk factor for vascular disease in humans. In addition to nutritional and genetic factors, an interruption of the coordinate regulatory function of S-adenosylmethionine has been proposed to be involved in the occurrence of hyperhomocysteinemia. The effect of oral S-adenosylmethionine on homocysteine metabolism in humans is unknown. W...

The metE gene, encoding S-adenosylmethionine synthetase (EC 2.5.1.6) from Bacillus subtilis, was cloned in two steps by normal and inverse PCR. The DNA sequence of the metE gene contains an open reading frame which encodes a 400-amino-acid sequence that is homologous to other known S-adenosylmethionine synthetases. The cloned gene complements the metE1 mutation and integrates at or near the chr...

We previously reported the isolation of a cDNA encoding the liver-specific isozyme of rat S-adenosylmethionine synthetase from a lambda gt11 rat liver cDNA library. Using this cDNA as a probe, we have isolated and sequenced cDNA clones for the rat kidney S-adenosylmethionine synthetase (extrahepatic isoenzyme) from a lambda gt11 rat kidney cDNA library. The complete coding sequence of this enzy...