Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chemoattractants such as N-formylmethionyl leucyl phenylalanine (FMLP) cause neutropenia in vivo. The sequestered neutrophils may block the microvasculature and contribute to respiratory distress. Neutrophils from humans receiving 1600 units vitamin E per day have reduced oxidative activity. To test whether vitamin E attenuates the responses of neutrophils to FMLP in vivo we gave rabbits four daily intramuscular injections of 100 mg vitamin E. Serum levels of the vitamin were 2.34 +/- 0.15 mg% compared to 0.19 +/- 0.04 mg% in control rabbits receiving placebo injections. On the fifth day testing was done before and after injecting FMLP. Variables monitored were the absolute granulocyte count (AGC), systolic, diastolic and mean blood pressures (MBP), heart rate, PO2, PCO2, pH and respiratory rate. When 0.5 microgram FMLP was injected intravenously the AGC decreased (at 2.5 min the percentage change was -89.7 +/- 8.0 with vitamin E and -97.0 +/- 2.7 without vitamin E; P = 0.2). MBP decreased also (% change, -29.0 +/- 13.0 with vitamin E and -36.3 +/- 16.0, without vitamin E). By 15 min recovery was seen (AGC % change, -26.0 +/- 17 with vitamin E and -78.7 +/- 10.5, without vitamin E; P = 0.01; MBP % change, -9.3 +/- 3.8 with vitamin E and -52.3 +/- 10.1 without vitamin E). Chromatographic analysis of serum extracts revealed increases in 6-keto-PGF1 alpha after stimulation. Studies with [3h]thymidine-labelled neutrophils showed that the sequestered cells return to the circulation. Vitamin E might facilitate this return by altering the adherence of neutrophils to endothelium. This possibility was tested by measuring the adherence to cultivated rabbit aorta endothelial monolayers of FMLP-stimulated neutrophils from vitamin E-treated rabbits. The percentage of neutrophils adhering was 32.5 +/- 3.5 with vitamin E and 60.0 +/- 7.1, without vitamin E. Thus vitamin E promotes the return of neutrophils to the circulation after chemotactic challenge and may do so by reducing their adherence to endothelium.
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PMID:The effect of vitamin E on rabbit neutrophil activation. 655 3

Vitamin E is composed of a family of eight isomers known as tocols; consisting of four tocopherols and four tocotrienols that exist in four isomeric forms: alpha (alpha), beta (beta), gamma (gamma), and delta (delta). Earlier we have demonstrated the radioprotective efficacy of the succinate ester of alpha-tocopherol (alpha-tocopherol succinate, TS). CD2F1 mice were injected subcutaneously with 400 mg/kg of TS and irradiated with different doses of 60Co gamma-radiation to determine its radioprotective efficacy. The dose reduction factor (DRF) for TS was also determined. We also investigated effects of TS on cytokine production by multiplex Luminex and message by quantitative RT-PCR. Peripheral blood cells were enumerated from irradiated (3 and 7 Gy) and non-irradiated mice. TS significantly protected mice against lethal doses of 60Co gamma-radiation and the DRF was 1.28. TS stimulated granulocyte-colony stimulating factor (G-CSF) with a peak at 24 h after drug injection, and also stimulated G-CSF message as judged by RT-PCR in bone marrow cells at 12 and 24 h after injection. Further, pancytopenia studies revealed that TS significantly reduced thrombocytopenia, neutropenia, and monocytopenia. TS had no significant effect on lymphocytes indicating that it may be helpful only for the myeloid cell compartments. The stimulation of G-CSF by TS supports its effects on myeloid cell compartments. Our studies indicate that TS may be developed as a radioprotectant for humans against the potentially lethal effects of radiation exposure.
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PMID:Tocopherol succinate: a promising radiation countermeasure. 1973 42