Cardiac and renal mast cells: morphology, distribution, fixation and staining properties in the guinea pig and preliminary comparison with human.

In guinea pig (GP) and human heart and kidney cell or tissue preparations fixed with Carnoy's fluid (but not with formol-saline), mast cells (MC) were extremely well preserved and could be detected after staining with alcian blue (AB). Although histamine content and distribution in GP and human heart appeared to be different, morphological and histochemical studies of MC suggested a similarity between the two species and a clear distinction from rat peritoneal MC.