Mepacrine Labelling Test and Uranaffin Cytochemical Reaction in Human Megakaryocytes

Summary

5-HT storage organelles were observed by electron microscope analysis in human megakaryocytes. They were less numerous per unit of surface than in platelets. Their number depended on the visualization technique employed. Thus after fixation with calcium-enriched glutaraldehyde a higher number of very opaque organelles was observed than of uranaffin-positive organelles after the cytochemical uranaffin reaction. With conventional electron microscopy deep black granules characteristic of dense bodies were not observed.

Fluorescent microscopy showed greenish-yellow granules distributed throughout the whole cytoplasm in 96 ± 1.4% of normal megacaryocytes incubated with mepacrine. In 85.6 ± 5%, 5.28 ± 1.28 granules per 10 ¼m² were observed.

With the mepacrine labelling test, 74% of the megakaryocytes of a patient with Hermansky-Pudlak syndrome contained no granules. A similar finding was made in the platelets of the same patient. This suggests that mepacrine also stains the dense bodies in the megakaryocytes and that in the Hermansky-Pudlak syndrome the platelet anomaly is secondary to a megakaryocyte anomaly.

Key words

Megakaryocyte dense bodies - Hermansky-Pudlak syndrome - Mepacrine-labelling test

• References

• 1 Pletscher A, Prada MDa. The organelles storing 5-hydroxytryptamine in blood platelets. Biochemistry and pharmacology of platelets. Ciba Foundation Symposium 35 (New Series). 261-286 Elsevier Excerpta-Medicai; North Holland, Amsterdam, Oxford, New York: 1975
• 2 Holmsen H, Day HJ, Storm E. Adenine nucleotide metabolism of blood platelets. VI. Subcellular localisation of nucleotide pools with different functions in the platelet release reaction. Biochim Biophys Acta 1969; 186: 254-266
• 3 Paulus JM. DNA metabolism and development of organelles in guinea pig megakaryocytes: a combined ultrastructural, autoradiographic and cytophotometric study. Blood 1970; 35: 298-311
• 4 White JG. Serotonin storage organelles in human megakaryocytes. Am J Pathol 1971; 403-406
• 5 Tranzer JP, Da Prada M, Pletscher A. Storage of 5-hydroxytryptamine in megakaryocytes. J Cell Biol 1972; 52: 191-197
• 6 Da Prada M, Pletscher A. Accumulation of basic drugs in 5-hydroxytryptamine storage organelles of rabbit blood platelets. Eur J Pharmacol 1975; 32: 179-185
• 7 Skaer RJ. Platelet degranulation. Platelets in biology and pathology. Elsevier, Biomedical Press; North Holland: Gordon. Ed. 1981. 2 321-343
• 8 Rendu F, Breton-Gorius J, Trugnan G, Castro-Malaspina H, Andrieu JM, Bereziat G, Lebret M, Caen J. Studies on a new variant of the Hermansky-Pudlak syndrome: qualitative, ultrastructural and functional abnormalities of the platelet-dense bodies associated with a phospholipase A defect. Am J Hematol 1978; 4: 387-399
• 9 Rabellino EM, Nachman RL, Williams N, Winchester RJ, Ross GD. Human megakaryocytes. I. Characterization of the membrane and cytoplasmic components of isolated marrow megakaryocytes. J Exp Med 1979; 149: 1273-1287
• 10 Rabellino EM, Levene RB, Leung LLK, Nachman RL. Human megakaryocytes. II. Expression of platelet proteins in early marrow megakaryocytes. J Exp Med 1981; 154: 88-100
• 11 Bessis M. Cellules du sang. Masson. Ed 1972: 483-496
• 12 Richards JG, Da Prada M. Uranaffin reaction: a new cytochemical technique for the localisation of adenine nucleotides in organelles storing biogenic amines. J Histochem Cytochem 1977; 25: 1322-1336
• 13 Lorez HP, Da Prada M, Rendu F, Pletscher A. Mepacrine a tool for investigating the 5-hydroxytryptamine organelles of blood platelets by fluorescence microscopy. J Lab Clin Med 1977; 89: 200-206
• 14 Breton-Gorius J, Reyes F. Ultrastructure of human bone marrow cell maturation. Int Rev Cytol 1976; 46: 267-280
• 15 Gerrard JM, Rao HR, White JG. The influence of reserpine and ethylenediaminetetraacetic acid (EDTA) on serotonin storage organelles of blood platelets. Am J Pathol 1977; 87: 633-642
• 16 Hourdillé P, Bernard P, Belloc F, Pradet A, Sanchez R, Boisseau MR. Platelet abnormalities in thermal injury. Study of platelet dense bodies stained with mepacrine. Haemostasis 1981; 10: 141-153
• 17 Da Prada M, Richards JG, Kettler R. Amine storage organelles in platelets. Platelets in biology and pathology. Elsevier, North Holland. Biomedical Press Gordon Ed 1981; 2: 107-145