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Factors in snake venoms that increase capillary permeability
1Department of Biochemistry, Colorado State University, Fort Collins 80523.
The Journal of Pharmacy and Pharmacology
|November 1, 1989
Summary
Snake venom components can increase capillary permeability. Researchers isolated a factor from Taiwan cobra venom, finding cardiotoxins and Mojave toxin exhibit this activity, likely via histamine release.
Area of Science:
- Pharmacology
- Toxicology
- Microcirculation Research
Background:
- Capillary permeability increasing (CPI) activity affects microvasculature.
- Agents like snake venoms, histamine, and prostaglandins cause CPI.
- Previous studies lacked systematic investigation into snake venom's CPI components.
Purpose of the Study:
- To systematically identify snake venom components responsible for CPI activity.
- To isolate and characterize a CPI factor from Naja naja atra venom.
- To elucidate the mechanism underlying venom-induced CPI.
Main Methods:
- Isolation of a CPI factor from Naja naja atra venom.
- Intravenous injection of Evan's blue dye to detect increased permeability.
- Testing cardiotoxins, Mojave toxin, neurotoxins, and myotoxins for CPI activity.
- Utilizing selective histamine H1-receptor blockers to investigate mechanisms.
Main Results:
- A CPI factor was isolated from Naja naja atra venom.
- Cardiotoxin from Naja naja kaouthia and Mojave toxin from Crotalus scutulatus scutulatus showed CPI activity.
- Elapidae cardiotoxins are CPI active, but not solely responsible.
- Histamine H1-receptor blockers effectively inhibited CPI induced by Naja naja atra and Crotalus scutulatus scutulatus venoms.
Conclusions:
- Elapidae cardiotoxins possess capillary permeability increasing activity.
- Presynaptic neurotoxins like Mojave toxin also contribute to CPI.
- Histamine release is the most probable mechanism for venom-induced CPI.