Adenosine deaminase (ADA) is an enzyme present in all organisms that catalyzes the irreversible deamination of adenosine and deoxyadenosine to inosine and deoxyinosine. Both adenosine and deoxyadenosine are biologically active purines that can have a deep impact on cellular physiology; notably, ADA deficiency in humans causes severe combined immunodeficiency. We have established a Drosophila mo...

Polymorphonuclear leukocytes (PMNs) are the major leukocytes in the circulation and play an important role in host defense. Intact PMN functions include adhesion, migration, phagocytosis, and reactive oxygen species (ROS) release. It has been known for a long time that adenosine can function as a modulator of adult PMN functions. Neonatal plasma has a higher adenosine level than that of adults;...

conclusions serum ada activity with high specificity percentage may be a useful alternative test in restricted resource areas to rule out diagnosis of ptb. however, serum ada activity is not a useful tool for tb diagnosis. mean serum ada level in the ptb group was clearly higher than the mean serum ada in the other three groups. mean serum ada was 26 iu/l in ptb patients, 19.48 iu/l in patients...

A period of prolonged vasodilation follows flow-restricted exercise of skeletal muscle. We tested the hypothesis that adenosine participates in mediating this vascular response. Vascularly isolated, anterior calf muscles of anesthetized dogs were stimulated to contract at a rate of 4 twitches/sec. Blood flow was held constant at 12.5 +/- 1.3 ml/min per 100 g which was about 14% of the expected ...

Since adenosine is present in normal brain tissue and cerebrosipinal fluid and since it dilates the pial vessels, it is possible that adenosine, in addition to H-+, is also a mediator of the metabolic regulation of cerebral blood flow. Evidence supporting this hypothesis was obtained under various experimental conditions characterized by achange in brain oxygen supply. The brain was frozen in...

OBJECTIVES While the role of adenosine pretreatment in animals has been well established, the role in humans has been controversial. We performed this prospective, randomized study to find out the usefulness of adenosine pretreatment in humans. PATIENTS AND METHODS Twenty patients undergoing coronary artery bypass surgery for severe triple vessel disease and left ventricular dysfunction (ejec...

objective(s): for determining the mechanism of anti-asthmatic effect of thymoquinone, this investigation evaluated the effect of thymoquinone in the presence of selective a2a and a2b adenosine receptor antagonists (zm241385 and mrs1706, respectively). materials and methods: seventy guinea pigs were randomly divided to 7 groups; control (c), sensitized with ovalbumin (s), sensitized groups pretr...

BACKGROUND/AIM Treadmill test combined with myocardial perfusion scintigraphy (MPS) is a commonly used technique in the assessment of coronary artery disease. There are many patients, however, who may not be able to undergo treadmill test. Such patients would benefit from pharmacological stress procedures combined with MPS. The most commonly used pharmacological agents for cardiac stress are co...

The mechanism of the therapeutic and prophylactic effects of carbamazepine (CBZ) in affective psychoses is unknown but may in part be related to the potent competitive interaction of CBZ with adenosine-binding sites in the brain. The anticonvulsant and sedative properties of CBZ are reminiscent of the effects evoked by adenosine-agonists and contrast sharply with the opposite actions of adenosi...

Background: Adenosine deaminase (ADA) and 5ʹ-nucleotidase (5ʹ-NT) play a crucial role in adenosine metabolism in healthy individuals. Adenosine is an inflammatory mediator of asthma. Changes in adenosine metabolism and role of ADA and 5ʹ-NT in regulating adenosine level in asthmatics and correlation of these changes with severity of asthma are not clearly understood. Methods: In this study, we ...