| Autor: |
Ribeiro JM; Harvard School of Public Health, Department of Tropical Public Health, Boston, MA 02115., Endris TM, Endris R |
| Jazyk: |
angličtina |
| Zdroj: |
Comparative biochemistry and physiology. A, Comparative physiology [Comp Biochem Physiol A Comp Physiol] 1991; Vol. 100 (1), pp. 109-12. |
| DOI: |
10.1016/0300-9629(91)90190-n |
| Abstrakt: |
1. Pilocarpine-induced saliva of the soft tick Ornithodoros moubata inhibits platelet aggregation induced by ADP or collagen, even when diluted 2000 times into platelet rich plasma. 2. Saliva contains apyrase (ATP-diphosphohydrolase) activity, which has an optimal pH of 7.0 for ADP and of 8.0 for ATP hydrolysis, respectively. Both Ca2+ and Mg2+ activate the reactions. 3. The mean specific activities for ATP and ADP hydrolysis at pH 7.5 were 0.97 and 0.74 mumoles orthophosphate/min/mg protein. 4. These results, which demonstrate for the first time such activities in the saliva of soft ticks, support the hypothesis that the saliva of blood sucking arthropods serves an anti-hemostatic role during feeding and that large amounts of salivary apyrase activity have evolved independently in hematophagous arthropods. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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