RESUMEN
The present work is a complementary contribution to the comprehensive study of the scorpion sting syndrome in Saudi Arabia. It deals with the identification and determination of medically important scorpions and the other ones, which were collected from two regions (Jazan and Al-Medina Al-Munawara), based on their morphology (the molecular phylogeny and venom characteristics will appear in subsequent publications). The specimens collected from those two regions were brought to the Research Center laboratories in several batches. Morphological identification of the collected specimens was done employing identification keys. There were 646 specimens collected from Jazan Region. A single species, Nebo hierichonticus (Family Diplocentridae), and five genera with four identified species, Parabuthus liosoma, Hottentotta jayakari (salei?), Compsobuthus werneri, Leiurus quinquestriatus (Vachoniolus globimanus?), Vachoniolus spp. (other species) and Orthochirus innesi (Family Buthidae), were classified as extant scorpions in the region. Three hundred and ninety-six specimens from Al-Medina Al-Munawara Region were categorized into eight groups; four of them were identified. Three buthids, Leiurus quinquestriatus, Androctonus crassicauda, Orthochirus innesi and one scorpion specimen, Scorpio maurus, were identified and classified as extant scorpions in this region. The other four species are still not completely identified. They are Vachoniolus (Buthacus minipectinibus?) globimanus? (Unidentified-1), Compsobuthus spp (arabicus?) (Unidentified-2), Compsobuthus spp (werneri?) (Unidentified-3) and a single specimen of Androctonus spp (australis?) (Unidentified-4), all of which belong to the family Buthidae.
RESUMEN
Inflammatory response induced by the venom of the Arabian sand viper Cerastes gasperettii was studied by measuring rat hind-paw edema. Cerastes gasperettii venom (CgV, 3.75-240 µg/paw), heated for 30s at 97°C, caused a marked dose and time-dependent edema in rat paw. Response was maximal 2h after venom administration and ceased within 24h. Heated CgV was routinely used in our experiments at the dose of 120 µg/paw. Among all the drugs and antivenoms tested, cyproheptadine and 5-nitroindazole were the most effective in inhibiting edema formation. Aprotinin, mepyramine, dexamethasone, diclofenac, dipyridamole, Nomega-nitro-L-arginine, quinacrine, and nordihydroguaiaretic acid showed statistically (p 0.001) significant inhibitory effect, but with variations in their inhibition degree. Equine polyspecific and rabbit monospecific antivenoms significantly (p 0.001) reduced edema when locally administered (subplantar) but were ineffective when intravenously injected. We can conclude that the principal inflammatory mediators were serotonin, histamine, adenosine transport factors, phosphodiesterase (PDE), cyclooxygenase, lipoxygenase and phospholipase A2 (PLA2), in addition to other prostaglandins and cytokines.