SEM CORROSION-CASTS STUDY OF THE MICROCIRCULATION OF THE FLAT BONES IN THE RAT

Bachground: Little is known about the organization of microcirculation in flat bones in comparison with long bones. This study, therefore, h elps us to determine the design of this vascular system in flat bones in relation to their structure and function. Methods: The organization of microvasculature in parietal, scapula, and ileum bones of 15 young sexually mature rats, aged 6-7 weeks, was studied by light and scanni ng electron microscopy (SEM) from vascular corrosion cast (vee), a res in-cast obtained material. Results: Our observations show that the pat tern of the microcirculation in flat bones is different in the thick a nd thin parts of such bones. Where the bone is thinner than 0.4 mm, on ly periosteal and dural network exist, Larger vessels which do not for m a real network connect the two tables of the bones in these regions. In thicker areas, the organization of the microvasculature is similar to that in long bones, with distinct periosteal, cortical and bone ma rrow networks. Moreover, in different bones, outer networks show sligh tly different characteristics according to the different adjacent stru ctures (dura mater, muscles etc.). Different types of vessels were rec ognized by comparing their different diameter, course and endothelial imprints. Conclusions: The microvascular patterns of the flat bones ar e strongly influenced by the bone thickness. The different microvascul ar systems can interact both with the bone modelling and remodeling an d with the variable metabolic needs, modifying the microvascular patte rn and the blood how This is even more important in view of the recipr ocal influence of the different networks within the same bone. (C) 199 7 Wiley-Liss, Inc.