ABSTRACT
Venom alkaline phosphatase was detected using a blotting method following electrophoresis. The enzyme gave strong reactions in some venoms, but was absent in other venoms, some within the same species. The mol. wt of the enzyme is close to 100,000 and its pI is between 3.6 and 4.8. The enzyme was inactivated by EDTA and 2-mercaptoethanol, and lost activity by freezing and thawing. Endogenous venom alkaline phosphatase can interfere with alkaline phosphatase-based detection methods. Pre-screening for endogenous venom alkaline phosphatase is recommended prior to using alkaline phosphatase-based detection methods when studying snake venom.
Subject(s)
Alkaline Phosphatase/analysis , Crotalid Venoms/enzymology , Agkistrodon , Animals , Electrophoresis, Polyacrylamide Gel , Isoelectric FocusingABSTRACT
A hemorrhagic toxin was isolated from Mojave rattlesnake venom. The isoelectric point of the toxin was 4.7 and its mol. wt was 27,000. Concentrations as low as 2 micrograms injected s.c. in mice caused hemorrhage greater than 5 mm in diameter. The toxin was fibrinogenolytic and hydrolyzed hide powder azure, casein and collagen. The toxin also partially inactivated complement. It had no activity against elastin, fibrin, and the chromogenic substrates S-2805, S-2302 and S-2238. Its esterolytic activity was 3% of the activity of the unfractionated venom. The enzymatic and hemorrhagic activities were inhibited by EDTA. The hemorrhagic toxin was absent or in low quantities in Mojave rattlesnake venoms containing Mojave toxin. Chromatography by HPLC easily distinguishes Mojave rattlesnake venoms into two types by the presence or absence of the hemorrhagic toxin.
Subject(s)
Crotalid Venoms/analysis , Hemorrhage/chemically induced , Toxins, Biological/isolation & purification , Animals , Complement System Proteins/immunology , Endopeptidases/isolation & purification , Mice , Mice, Inbred BALB C , Molecular Weight , Toxins, Biological/immunology , Toxins, Biological/pharmacologyABSTRACT
Murine macrophage-like cell lines were used to determine whether exogenously added prostaglandins and endogenous prostaglandins suppress interferon (IFN) synthesis in macrophages. The amount of IFN produced by J774A.1 cells induced with bacterial lipopolysaccharide (LPS) was reduced by 0.1 and 1 microM PGE1 or PGE2. These prostaglandins also inhibited Newcastle disease virus (NDV) induced IFN production, but only at a concentration of 1 microM. Thromboxane B2 at 0.01 to 1 microM had no effect on IFN production. Cells treated before, during, or before and during IFN synthesis with 0.15 to 4.8 microM indomethacin to inhibit prostaglandin synthesis did not increase IFN yields. Indomethacin also had no effect on NDV-induced IFN production by P388D1 and PU5-1.8 cells, and these cells remained nonresponsive to LPS for IFN production. These results indicate that endogenous levels of cyclooxygenase-dependent metabolites of arachidonic acid do not regulate IFN synthesis in macrophages.
