The dynamics of local tissue damage induced by Bothrops asper snake venom and myotoxin II on the mouse cremaster muscle: An intravital and electron microscopic study

Neutralization of edema, hemorrhage and myonecrosis induced by North American crotalid venoms in simulated first-aid treatments

“…ACL myotoxin in ACL venom is enzymatically inactive, or shows very little enzymatic activity (Johnson and Ownby, 1993a) while CVV myotoxin in CVV venom is catalytically active . Liu et al (1991), Lomonte et al (1993b), and Angulo et al (1997) reported that PLA2 myotoxins fram the venoms of T. mucrosquamatus, B.…”

“…Interestingly, Ownby et al (1986) found that antimyotoxin a serum The myonecrosis due to myotoxin a is measured in hours, not minutes, as with the PLA 2 myotoxins (Melo and Ownby, 1996). Lomonte et al (1993b) also showed that myonecrosis induced by the PLA 2 myotoxin from B. asper, Myotoxin II, was seen only 3 to 4 minutes after application. Apparently, the topical DMSO-p-BPB or saline-p-BPB cannot reach the site fast enough to prevent damage.…”

Crystallization and preliminary X-ray diffraction studies of piratoxin III, a D-49 phospholipase A2 from the venom of Bothrops pirajai

“…This is thought to arise from a substitution of the aspartate residue at position 49, the side chain of which is important in the binding of calcium ions (an essential cofactor), by a lysine residue (Holland et al, 1990;Scott et al, 1992;Arni et al, 1995). However, despite the low or lack of enzymatic activity, K-49 PLA 2 s exhibits several different pharmacological activities, such as post-synaptic neurotoxicity, oedema formation (Gutie  rrez & Lomonte, 1995), myotoxicity (Lomonte et al, 1994) and liposome and membrane disruption (Dõ Âas et al, 1991;Ruf®ni et al, 1992). The enzymatically active PLA 2 s (D-49 PLA 2 s) hydrolyse the sn-2 ester bond of 1,2-diacyl-3-sn-phosphoglycerides.…”

Efeito bactericida de Fosfolipases A2-Lys49: o papel da região C-terminal na atividade de Bothropstoxina-I em membranas biológicas e artificiais.

“…Apesar dos mecanismos, pelos quais as PLA 2 s exercem tais efeitos, ainda sejam pouco conhecidos, a função catalítica não é necessária para manifestação de algumas destas propriedades farmacológicas (LOMONTE et al, 1994b;PÁRAMO et al, 1998;SOARES et al, 2000). Identificando a importância da região C-terminal de BthTx-I no efeito bactericida contra linhagem E.coli, nós propusemos investigar o mecanismo de ação bactericida da proteína e a contribuição da região C-terminal para tal atividade, a partir de um estudo por partição de sondas fluorescentes segundo metodologia descrita por PÁRAMO (1998) e MARTÍNEZ DE TEJADA (1995).…”

“…Além disso, estas PLA 2 s evocam inflamação local e dor (TEXEIRA et al, 1994(TEXEIRA et al, , 2003CHACUR et al, 2003CHACUR et al, , 2004. Embora os mecanismos através dos quais as PLA 2 s causam tais efeitos sejam ainda pouco conhecidos, a função catalítica não é necessária para algumas destas propriedades farmacológicas (LOMONTE et al, 1994b;PÁRAMO et al, 1998, SOARES et al, 2000CHACUR et al, 2003CHACUR et al, , 2004 GIOTTO et al, 1998).…”