Homocysteine has been shown to increase glutathione levels in C3H/10T1/2 Cl 8 cells. The present paper confirms that this increase was specific for non-dividing cells. Several other thiols and disulfides, including cysteamine, mercaptoethanol and dithioerythritol, also increased glutathione, but the specificity for quiescent non-dividing cells was confined to homocysteine only. Cysteamine was m...

Plasma amino acid response of wethers to abomasal infusions of DL-methionine (DLM), DL-homocysteine thiolactone-HCl (HCTL) and N-acetyl-DL-methionine (NAM), in vivo rumen stability of the latter two methionine analogs and preintestinal absorption of HCTL were studied. The daily infusion of 1.06 g of DLM elevated molar percentage of methionine and lysine in plasma'and decreased molar percentage ...

In order to quantify adenosine production from the transmethylation pathway [S-adenosylmethionine (AdoMet)----S-adenosylhomocysteine (AdoHcy) in equilibrium adenosine + L-homocysteine] in the isolated guinea-pig heart under basal conditions (normoxic perfusion with 95% O2) and during elevated adenosine production (hypoxic perfusion with 30% O2), two methods were used. (1) Hearts were perfused w...

Increased oxidative stress, alterations of lipid metabolism and induction of thrombosis have been suggested to be pathogenic links which are present between hyperhomocysteinaemia and atherosclerosis. However, the mechanism by which homocysteine (Hcy) can promote atherogenesis is far from clear and it has been debated. In the presence of cardiovascular risk factors, endothelial dysfunction is th...

Homocysteine (Hcy) and its metabolite Hcy-thiolactone (HTL) are implicated in cardiovascular disease (CVD). Recent studies show that HTL is a predictor of acute myocardial infarction in CVD patients, independent of established risk factors and plasma total Hcy. HTL is formed in all cell types as a result of error-editing reactions in protein biosynthesis. Its ability to N-homocysteinylate prote...

AIMS Increased levels of homocysteine (Hcy) form an independent risk factor for cardiovascular disease. In a previous study we have shown that Hcy induced phosphatidylserine (PS) exposure to the outer leaflet of the plasma membrane in cardiomyocytes, inducing a pro-inflammatory phenotype. In the present study the mechanism(s) involved in Hcy-induced PS exposure were analyzed. METHODS H9c2 rat...

Epilepsy is a chronic neurological disorder characterised by recurrent epileptic seizures. Understanding the mechanisms by which it initiates and develops, as well as its modulating factors, are of great scientifi c interest. Experimental models of epilepsy are useful for understanding these mechanisms. Homocysteine, an amino acid endogenously generated in the body, together with its reactive m...

Although hyperhomocysteinemia (HHcy) elicits lower than normal body weights and skeletal muscle weakness, the mechanisms remain unclear. Despite the fact that HHcy-mediated enhancement in ROS and consequent damage to regulators of different cellular processes is relatively well established in other organs, the nature of such events is unknown in skeletal muscles. Previously, we reported that HH...