[The relationship between cytosolic Ca2+ and two kinds of granule number in activated platelets].
The numerical density (Nv) of the alpha-granule (alpha G) and dense granule (dG) measured by using electron microscopic morphometry and the cytosolic free calcium concentration ([Ca2+]i) by using Ca-fluorescent indicator were observed for studying the relationship of [Ca2+]i and Nv of alpha G and dG in platelets activated by A23187, thrombin or ADP. The results showed that the [Ca2+]i rose markedly by A23187. Thrombin or ADP could also induce an increase of [Ca2+]i concentration-dependently. Under 3 different degrees of activation induced by different agonists, the close relationship between Nv of both granules, alpha G and dG, and [Ca2+]i in platelets was found (Pr(alpha G) < 0.05, Pr(dG) < 0.01). These findings indicate that the increase in [Ca2+]i may enhance the secretion of alpha G and dG.
Ding
J
J
Department of Biophysics, Shanghai Medical University, Shanghai 200032.
Yu
Z
Z
Rong
D M
DM
Zhong
C S
CS
D000818:Animals; D001693:Biological Transport, Active; D001792:Blood Platelets / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D019007:P-Selectin / Q000378:metabolism*; D015800:Protozoan Proteins / Q000378:metabolism; D011817:Rabbits
C114436:DG 32 protein, Sarcocystis muris; D019007:P-Selectin; D015800:Protozoan Proteins; D002118:Calcium