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THE USE OF 131 I‐ALBUMIN IN ASSAYS OF DRUGS THAT INCREASE VASCULAR PERMEABILITY IN THE SKIN OF GUINEA‐PIGS
Author(s) -
Garlick DG
Publication year - 1965
Publication title -
australian journal of experimental biology and medical science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0004-945X
DOI - 10.1038/icb.1965.51
Subject(s) - histamine , vascular permeability , bradykinin , albumin , evans blue , chemistry , pharmacology , serum albumin , endocrinology , medicine , chromatography , biochemistry , receptor
Summary The measurement of radioactivity of skin pieces excised from guinea‐pigs with circulating 131 I‐albumin provided a useful means of relating increased exudation of the protein to the dose of permeability‐increasing drugs, injected intradermally. Intravenous injection of Evans blue dye, given at the same time as 131 I‐albumin, permitted visual identification of skin areas with increased vascular permeability, due to the exudation of dye‐albumin complex. After establishing a suitable experimental procedure, linear log dose‐response curves were obtained for three drugs, viz. histamine, bradykinin and compound 48/80. The use of two‐way restraints of Latin and Youden squares for injection patterns meant that the effect of sites of injections, as well as differences between animals, could be determined. Their effects were frequently found to be significant. A 6 × 5 Youden square, divided between two guinea‐pigs, provided a convenient plan for a comparative dilution assay. The linear regressions for histamine and for the polypeptide, bradykinin, were significantly different. The linear regressions for histamine and for the histamine‐liberator, compound 48/80, were significantly parallel. At an equipment level, the dose of compound 48/80 was approximately 27‐fold greater than that for histamine; or 5·6‐fold greater in the comparison of their molar concentrations.