Analysis of diameters of human pituitary hormone secretory granules.

Measurements were made on electron micrographs of six human anterior pituitary glands of the maximal diameters of secretory granules in 130 cells, average 91 granules per cell. This was done in an attempt to classify the various hormone types solely by differences in the mean diameters of the secretory granules. The range of diameters in nanometers could be segregated into six subgroups of the following suggested functions: 135.5 +/- 13.6 TSH, 181.6 +/- 9.3 LH, 226.0 +/- 19.4 FSH, 356.8 +/- 30.5 ACTH/MSH, 452.9 +/- 23.8 GH, 559.9 +/- 38.0 prolactin.