Anti-immunoglobulin induced histamine release from naturally abundant basophils in the snapping turtle, Chelydra serpentina.

The dose response, temperature sensitivity, time course and calcium dependency of histamine release from snapping turtle basophils treated with rabbit anti-turtle immunoglobulin (RATIg) sera was explored. This investigation indicated that the level of histamine release induced by RATIg was dependent upon the concentration of RATIg with concentrations of 350 mcg/ml inducing optimal release. In addition, release was temperature dependent with release increasing over a temperature range of 10 degrees C to maximal at 27 degrees C. Release was also dependent on the length of exposure to RATIg. Release increased steadily over a time period of 0 to 30 minutes with the higher concentrations of RATIg inducing the most rapid release. Basophil-histamine release was also found to be calcium dependent. This study indicates that the snapping turtle basophil possesses similar characteristics to that of its mammalian counterparts. It is proposed that the very wide temperature range over which turtle basophils release histamine is an important feature in he immune resistance of this ectothermic animal.