Alkaline phosphatase role in bone marrow and spleen hemopoietic cells recovery after mouse whole-body irradiation

Hematopoietic tissue is consisted of two distinctly different tissues, the first part is the hematopoietic stem cells and the second tissue is a mixture of many supportive cells which the most important one of them is alkaline phosphatase (ALP)-secreted-fibroblastic cells (FBCs). It was thought that FBCs play an important role in the hematopoiesis through ALP secretion. Our previous studies indicated that the ALP secretion in bone marrow (BM) increased after a whole mouse body irradiation when the BM cellular component is completely destroyed and, then it was decreased when the BM regain its cellular component. We performed some experiences to verify if there is any role to the ALP in the hematopoiesis. We irradiated three groups of mice to non-lethal dose, the first one was injected by Tetramizole (anti-ALP) 24 hours before irradiation, and the second was injected by Lisinopril (anti-hematopoiesis) 24 hours before irradiation and the third left without any injection. The fourth left as control. Many histological sections were taken from BM and spleen on 1, 3, 7 and 30 days after irradiation to perform ALP-histological detection. These experiences were repeated to count BM cells. ALP secretion level in the BM was reached the maximum 3 days after irradiation without any injection when the cell number was in minimum then, the level of ALP start to decrease and the cell number start to increase. ALP secretion delayed when the mice were injected by Tetramizole and BM cell population also delayed to return to its normal position. But, the ALP secretion increased directly after irradiation when the mice were injected by Lisinopril which, the ALP secretion, normally reached the maximum by the third day. These results may indicate a role to the ALP in BM and spleen hematopoietic cell recovery (author).