The use of rat kidney instead of guinea pig brain as the source of histamine-N-methyltransferase for the enzymatic assay of histamine was found to improve the sensitivity of the assay. A partially purified preparation (ammonium sulfate fractionation) of the kidney enzyme was 20-to M-fold more active
Serum histamine and the elicitation of murine contact sensitivity
β Scribed by Ian Kimber; Marie Cumberbatch; John W. Coleman
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 394 KB
- Volume
- 11
- Category
- Article
- ISSN
- 0260-437X
No coin nor oath required. For personal study only.
β¦ Synopsis
We report that challenge of previously contact-sensitized mice results in a significant increase in the concentration of serum histamine. In an attempt to determine whether this phenomenon might form the basis of an alternative method for the evaluation of elicitation reactions in experimental contact sensitivity, we have compared challenge-induced increases in ear thickness with elevations in serum histamine. Challenge of sensitized mice revealed that both ear thickness changes and increases in the serum level of histamine were dependent upon the concentration of oxazolone used for sensitization. The kinetics of changes in serum histamine concentration were found to be biphasic, with a small increase measurable 2 h following challenge and the maximal response at 24 or 48 h. In contrast, increases in ear thickness were monophasic, although maximum responses were also observed at 24 h. It is concluded that, although they do not exactly parallel increases in ear thickness, changes in histamine concentration may provide a useful serological correlate of the challenge reaction in contact sensitivity.
π SIMILAR VOLUMES
## Abstract Freshly explanted MDAY murine tumor cells are sensitive to lysis mediated by fresh normal rabbit serum. The sensitivity, which increases with the age of the tumor, is rapidly lost upon shortβterm culture, and takes place at 37 Β°C but not at 4 Β°C. Cellular components released into the m
## Abstract The sensitivity of cells to serum deprivation depends upon whether they are transformed. Most supplies of 3T3 cells are of this type and are considerably less sensitive than untransformed cells. In addition, the apparently simple manoeuvre of reducing serum levels has considerable effec