Analysis of IgE turnover in non‐sensitized and sensitized rats

Abstract

BACKGROUND: Although the levels of immunoglobulin E (IgE) in the circulating blood are often elevated in patients with allergic diseases, such levels cannot always be considered as pathognomonic signs of allergy. The induction of allergic reactions in the tissue was inferred to be related to the amount of IgE passing through the vascular wall. AIMS: We attempted to clarify which compartment, the intravascular or extravascular, plays an important role in the regulation of the turnover of rat IgE. METHODS: The level of DNP-specific rat IgE in the serum was estimated by IgE-capture enzyme-linked immunosorbent assay, and the turnover of IgE was analyzed from its pharmacokinetic parameters. RESULTS: The transfer rate constants from the central to tissue compartment (Kct) were larger than those from the tissue to central compartment (Ktc) irrespective of the sensitized state. The value of the distribution volume of the tissue compartment (Vt) was larger than that of the distribution volume of the central compartment (Vc) irrespective of the sensitized state. CONCLUSIONS: These Findings suggest that the short half-life of rat IgE in the circulation could be attributable to the distribution of IgE from the intravascular to the extravascular compartment.

Azelastine and suplatast shorten the distribution half‐life of IgE in rats

“…administration in rats irrespective of the sensitized state. 1 In the present study, we demonstrated that the levels of monoclonal DNP-specific rat IgE underwent a rapid decrease in the suplatast-administered or azelastine-administered group in comparison with those of the distilled water-administered group under non-sensitized conditions at 15 min-3 h following administration of IgE. Pharmacokinetic analysis revealed that the values of the distribution half-life (t 1/2 a) in the suplatast-administered or azelastineadministered group were smaller than those of the distilled water-administered group irrespective of the sensitized state, suggesting that the anti-allergic drugs used can facilitate the excretion of IgE from the circulation.…”

“…Calculation of kinetic parameters was performed as previously described. 1 Statistical analysis was performed by the unpaired Student's t-test for betweengroup comparisons. Data are expressed as mean ± standard deviation (SD).…”

“…Sensitization of rats was performed as described previously. 1 Group A was given distilled water orally. Group B was given 100 mg/kg of suplatast orally.…”

“…Recently, we demonstrated that the short half-life of rat IgE in the circulation was attributable to the distribution of IgE from the intravascular to extravascular compartment. 1 Furthermore, it was expected that the alteration of IgE turnover in the circulation could lead to the modification of IgE-mediated inflammation at the extravascular site.…”