Affiliations: National Institute of Traumatology and Emergency Medicine, Department of Experimental Surgery, Budapest, Hungary | Krankenhaus München-Schwabing, Munich, Germany
Note: [] Corresponding author: Zsolt Vendégh, MD, PhD, National Institute of Traumatology and Emergency Medicine, Department of Experimental Surgery, 1081 Budapest, Fiumei út 17, Hungary. Home: 1126 Budapest, Orbánhegyi út 47, Hungary. Tel.: +36 1 299 77 00 or +36 30 94 93 340 (mobile); Fax: +36 1 35 56 094; E-mail: vendegh@vivamail.hu
Abstract: Different bones have different blood supplies, which may influence bone healing. Therefore, elucidation of the mechanisms involved in the regulation of bone marrow blood flow in different bones is of high clinical importance. To assess the micro circulation of bone marrow of the femur and tibia simultaneously, flow velocities were continuously measured by a two-channel laser-Doppler flowmeter. The probes were introduced into the femoral and tibial diaphysis, respectively, in the anesthetized rabbit. Changes in micro circulation of the bone marrow were elicited by intra-arterial bolus injections of vasoactive substances: epinephrine (E), calcitonine-gene related peptide (CGRP), substance P (SP), sodium nitroprusside (SNP), E and Ebrantil. Systemic arterial blood pressure was recorded with an electro-manometer. Micro vascular resistance (MVR) and 50% recovery time (50RT) to baseline flow level were calculated from the measured data. Flow velocity in the femur was significantly higher. Epinephrine considerably reduced micro vascular blood flow, which could be significantly warded off by Ebrantil. CGRP and SP did not change MVR. Application of SNP resulted in reduction of flow velocity, but it also decreased MVR. No statistically significant differences were found between reactions of the micro circulation in the two marrows. These results suggest that there are no significant differences between the blood flow response patterns of these two bone marrow sites, thus the regulation patterns of the micro circulation of the two bones are also similar.
Keywords: Bone marrow, vasoactive substances, laser-doppler flowmetry, micro circulation
