Objective: To analyze whether immunogold labeling density for basic fibroblastic growth factor in granules is compatible with the activation stage of mast cells.
Study design: Cytoplasmic features and granules of 46 mast cells were examined at the ultrastructural level. The cells were classified according to their activation stage, namely, whether resting, initially activated, fully degranulated or piecemeal degranulated. Granules were classified as electron lucent, moderate or dense granules. Gold particles per secretory granules in the cells were counted. Recently described quantitative analysis techniques were used for evaluation.
Results: There is a statistically meaningful relationship between the activation stage of mast cells and their immunogold labeling density. The number of different types of granules encountered in a cell depends on the type of the cell. The distribution of gold particles among the secretory granules depends upon the cell. The type of granule does not have an individual effect on the number of particles, as indicated by an overall statistical analysis of granules, cells and their interaction effects.
Conclusion: A count of gold particles in the cells can be used as a strong biological indicator. Therefore the number of gold particles might be very useful for comparative studies related to the secretion of this growth factor under different conditions.