Drugs online research references
Am J Physiol. 1987 Feb;252(2 Pt 2):H368-73.
Purine efflux after cardiac ischemia: relevance to allopurinol cardioprotection.
Grum CM, Ketai LH, Myers CL, Shlafer M.
Allopurinol is thought to protect hearts against damage due to hypoxia or ischemia by inhibiting xanthine oxidase and oxygen radical generation. We subjected isolated rabbit hearts, equilibrated by perfusion at 37 degrees C, to 1 h of global ischemia at 27 or 37 degrees C with or without brief pretreatment with 100 microM allopurinol. The total absence of xanthine or uric acid in the coronary effluent following ischemia, the presence of hypoxanthine (25 +/- 4 microM peak concentration), and the failure of allopurinol to alter purine washout profiles or postischemic cardiac function suggest that rabbit myocardium lacks xanthine oxidase or dehydrogenase. Data obtained with a similar rat heart preparation showed appreciable formation of xanthine (12 +/- 2 microM peak) and uric acid (10 +/- 3 microM). Allopurinol pretreatment inhibited xanthine and uric acid formation and significantly improved key indicators of postischemic left ventricular function. We conclude that there is species dependency in the myocardial activity of xanthine oxidase or dehydrogenase, that when present it can be inhibited by acute allopurinol pretreatment, and that xanthine oxidase activity and its ability to generate oxygen radicals are not universal contributors to cardiac ischemic damage.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3812751&dopt=Abstract
Am Surg. 1993 Dec;59(12):797-800.
Superoxide dismutase and allopurinol improve survival in an animal model of hemorrhagic shock.
Tan LR, Waxman K, Clark L, Eloi L, Chhieng N, Miller B, Young A.
Department of Surgery, University of California Irvine College of Medicine.
We studied the efficacy of resuscitation with antioxidants in an animal model of hemorrhagic shock. Male Sprague-Dawley rats were anesthetized, and 27 mL/kg of blood was withdrawn from the carotid artery over 2 minutes. The animals remained in hemorrhagic shock for 45 minutes, followed by 1 hour of resuscitation. Experimental groups were as follows: 1) 15,000 u/kg superoxide dismutase (SOD) in 54 mL/kg lactated Ringer (LR); 2) 175,000 u/kg catalase (CAT) in LR; 3) 15,000 u/kg SOD+175,000 u/kg CAT in LR; 4) allopurinol in LR; 5) deferoxamine bound to pentafraction (DFO), 27 mL/kg; 6) pentafraction alone; and 7) LR alone. Compared with resuscitation with LR alone, SOD and allopurinol improved survival over 72 hours, P < 0.05. Survival with SOD+CAT was not different from LR alone. Deferoxamine bound to pentafraction did not increase survival over that with pentafraction alone. CAT had increased mortality compared to LR, P < 0.01. The efficacy of both SOD and allopurinol in decreasing mortality suggests the importance of superoxide radicals after hemorrhagic shock and resuscitation. These and other antioxidants are potential therapeutic agents in the clinical setting of trauma and hemorrhagic shock.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8256931&dopt=Abstract
Cancer Res. 1984 Jul;44(7):3144-8.
Hypoxanthine concentrations in normal subjects and patients with solid tumors and leukemia.
Wung WE, Howell SB.
Mean plasma hypoxanthine (Hyp) concentrations determined by high-pressure liquid chromatography were 0.56 microM (range, 0.2 to 1.9 microM) in 16 normal subjects, 0.68 microM (range, 0.1 to 1.1 microM) in 10 untreated acute leukemic subjects, and 0.89 microM (range, 0.3 to 2.6 microM) in 14 solid tumor patients. Despite large differences in Hyp concentration between patients, every 4-hr sampling, indicated that diurnal variation in individual patients was small (maximum, 2.3-fold). While the mean plasma and malignant effusion Hyp concentrations did not differ significantly, bone marrow plasma Hyp concentration averaged 4.0-fold greater than that of simultaneously drawn venous plasma. Allopurinol 300 mg p.o. caused a mean 1.5-fold increase in plasma Hyp within 3 hr. In 17 patients with acute leukemia, treatment with allopurinol at 300 mg daily plus initiation of chemotherapy caused a mean 7-fold increase in plasma Hyp to 4.6 microM (range, 1 to 12 microM). The ability of Hyp to modulate the toxicity of antimetabolites affecting purine synthesis (6- diazao -5- oxonorleucine , 6-methylmercaptopurine riboside, 6-mercaptopurine, and 6-thioguanine) was determined in vitro using human B-lymphoblast (WI-L2) and promyelocytic leukemia (HL-60) cell lines. Hyp permitted growth of both cell lines in the presence of clinically achievable concentrations of all 4 drugs, but the initial culture concentrations of Hyp required were above those found in patients. Since Hyp was consumed rapidly during the culture period, the average Hyp concentrations required for the protection of cells were actually much lower. We conclude that, in patients with acute leukemia receiving allopurinol during chemotherapy, plasma Hyp concentrations are significantly elevated; the potential for antagonism of antimetabolite activity is uncertain.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6539170&dopt=Abstract
online pharmacies ||
Hair Million herbal formula for hair loss and hair growth ||
Amoxicillin ||
Tramadol ||
Paxil ||
Rx Drugs USA, Prescription Drugs Online Pharmacy ||
Zithromax ||
online pharmacy ||
Antibiotics and prescription medications online literature ||
Antibiotics