ovalbumin and gadolinium-chloride

Transient receptor potential canonical channel 3 (TRPC3) proteins function as non-voltage-gated Ca

Topics: Acetylcholine; Airway Remodeling; Aminophylline; Animals; Antibodies; Asthma; Calcium; Cell Proliferation; Cells, Cultured; Dexamethasone; Gadolinium; Hydroxyproline; Mice; Muscle Contraction; Muscle, Smooth; Ovalbumin; Protein Biosynthesis; RNA Interference; RNA, Small Interfering; TRPC Cation Channels

The aim of the present study was to evaluate the influence of Kupffer cell phagocytosis blockade (KCPB) on the production of reaginic (IgE) and non-reaginic (IgG1) ovalbumin antibodies in an experimental animal model. Forty-two female heterozygous Gunn rats were injected with two 100 micrograms doses of ovalbumin separated by 13 days, into jugular vein (Group I, n = 10), portal vein (Group II, n = 10), jugular vein with prior KCPB (Group III, n = 10) and portal vein with prior KCPB (Group IV, n = 12). KCPB was induced with gadolinium chloride (5 mg/kg body weight, 24 hr before each ovalbumin administration). Antibodies were determined by passive cutaneous anaphylaxis in sera obtained 12 days after the first dose of ovalbumin and 8 days after the second one. No antibodies were detected at any time in Group II. The maximum response was observed in Group IV in which, after two doses of ovalbumin, 100% of the animals presented IgG1 and 58% presented detectable IgE antibodies. Differences between group IV and the other groups were statistically significant. This phenomenon does not seem to be due to a systemic effect of gadolinium chloride since humoral response was not increased in Group III with respect to Group I. It is concluded that the liver represents a barrier to IgE and IgG1 sensitization. KCPB not only eliminates this barrier, but also clearly increases antibody production to a protein antigen (ovalbumin) arriving at the liver through the portal vein.

Topics: Animals; Antibody Formation; Antibody Specificity; Female; Gadolinium; Immunoglobulin E; Immunoglobulin G; Kupffer Cells; Male; Models, Biological; Ovalbumin; Phagocytosis; Rats; Rats, Gunn; Rats, Wistar

Data in the literature concerning the role of macrophages in anaphylaxis are contradictory. In the present study the effect of macrophage blockade induced by gadolinium chloride (GdCl3) on anaphylactic shock was investigated. Our observations show that GdCl3 prevents the lethal anaphylactic shock of mice sensitized to ovalbumin. GdCl3 given i.v. in a dose of 1 mg/100 g body weight 24 or 48 h before the elicitation of anaphylactic shock resulted in 90% survival, compared to the 43% survival in the control group. The same dose of this rare earth metal salt also greatly reduced the mortality in mice sensitized with ovalbumin containing Bordetella pertussis vaccine, and the symptoms of anaphylaxis including the accumulation of 5-hydroxytryptamine in the liver. Our results suggest that macrophages play an important role in anaphylaxis.

Topics: Anaphylaxis; Animals; Gadolinium; Liver; Macrophages; Male; Mice; Ovalbumin; Pertussis Vaccine; Serotonin