An inherited deficiency of adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4) is associated with an autosomal recessive form of severe combined immunodeficiency disease. Affected patients exhibit markedly reduced or absent adenosine deaminating activity in various tissues. In this study we have demonstrated the presence of a low level aminohydrolase activity in 11 different normal and a...

-The objective of this investigation was to determine whether the regulation of extracellular adenosine levels by smooth muscle cells (SMCs) from conduit arteries (aorta) and resistance microvessels (renal arterioles) is different in spontaneously hypertensive rats (SHR) versus normotensive Wistar-Kyoto (WKY) rats. Basal extracellular adenosine levels were decreased in cultured aortic and arter...

1. The liberation of ammonia from adenosine 5'-phosphate (AMP) and adenosine and the release of inorganic phosphate from AMP were investigated in homogenates of bovine and human parotid glands. 2. Adenosine phosphate deaminase (AMP deaminase) was purified from bovine and human parotid glands. The enzyme preparations obtained were free from adenosine deaminase and 5'-nucleotidase activities. 3. ...

Adenosine, acting both through G-protein coupled adenosine receptors and intracellularly, plays a complex role in multiple physiological pathophysiological processes by modulating neuronal plasticity, astrocytic activity, learning memory, motor function, feeding, control of sleep aging. Adenosine is involved stroke, epilepsy neurodegenerative pathologies. Extracellular concentration the brain t...

INTRODUCTION About 20% of the cases of human severe combined immunodeficiency are the result of the child being homozygous for defective genes encoding the enzyme adenosine deaminase. To our knowledge, the mutation pattern in Arab patients with severe combined immunodeficiency has never been reported previously. CASE PRESENTATION A 14-month-old Arab boy had clinical features typical of severe...

In most instances, marked deficiency of the purine catabolic enzyme adenosine deaminase results in lymphopenia and severe combined immunodeficiency disease. Over a 2-yr period, we studied a white male child with markedly deficient erythrocyte and lymphocyte adenosine deaminase activity and normal immune function. We have documented that (a) adenosine deaminase activity and immunoreactive protei...

We employed intracoronary infusion of adenosine deaminase to test the hypothesis that endogenous adenosine contributes to regulation of coronary blood flow following acute reductions in coronary artery pressure. In 16 closed-chest anesthetized dogs, we perfused the left circumflex coronary artery from a pressurized arterial reservoir and measured coronary blood flow following changes in perfusi...

The purpose of this study is to determine the relationship between enzymatic antioxidants such as glutathione reductase and s-transferase prolidase adenosine deaminase in patients diagnosed with pancreatic cancer. Prolidase, deaminase, activities were determined spectrophotometrically blood sera collected from healthy control subjects included study. In cancer, mean value enzymes decreased, whi...

Adenosine modulates immune/inflammatory reactions. This study investigates the expression of adenosine deaminase in the inflamed colon, the effects of adenosine deaminase inhibitors on established colitis, and the recruitment of adenosine receptors by endogenous adenosine after adenosine deaminase blockade. Adenosine deaminase expression was determined by Western blot. The effects of 4-amino-2-...

OBJECTIVE Adenosine deaminase acts on adenosine and deoxyadenosine metabolism and modulates the immune response. The adenosine deaminase G22A polymorphism (20q.11.33) influences the level of adenosine deaminase enzyme expression, which seems to play a key role in maintaining pregnancy. The adenosine deaminase 2 phenotype has been associated with a protective effect against recurrent spontaneous...