Serum changes induced by intramedullar experimental administration of bisphosphonates

Bisphosphonates, stable analogues of pyrophosphate, have the ability to bind to bone molecules, possessing anti-resorbtion properties influenced by the radicals linked to the carbon group of their structure. Bisphosphonates link to the hydroxyapatite of the mineral surfaces and are selectively internalized by osteoclasts, whose activity they inhibit, jeopardizing the osteoblastic activity. The purpose of this study is to determine the influence of intramedular administration (at the hip bone) of bisphosphonates on the serum values of alkaline phosphatase, total Ca, Ca2+, proteins and serum osteocalcin in a lot of experience Wistar rats. Fifteen Wistar rats of experience, five in the control group and 10 in the experimental group. All rats underwent surgery to create a bone defect with a 1.5 mm diameter bone-bur at the right femur transcortical through the medullar canal. Rats from experimental group were divided into two groups: group A, who received Zometa 1 mL single dose intramedular, intraoperative and group B, who received Zometa 1 mL in divided doses daily, 0.1 mL for 10 days. 3 mL of blood from the frontal sinus were collected from each subject at 24 hours, 14 days and 21 days postoperatively. From the blood samples were determined: alkaline phosphatase [U/L], seric proteins [g/dL], total Ca [mmol/L, mg/dL], osteocalcin [mmol/L]. The data were statistically analyzed using the ANOVA test. We found an increase in alkaline phosphatase [U/L] in all groups studied. In group B there was a significant decrease in total Ca levels [mg/dL] throughout the experiment compared with controls (11.82→10.36→9.25 mg/dL; 2.95→2.59→2.31 mmol/L; p=0.001). Ca2+ has changed significantly both in group A (1.18→1.25→1.25 mmol/L; p=0.01) and group B (1.21→1.24→1.13 mmol/L; p=0.02). Serum proteins were significantly reduced both in the control group (9.4→8.5→8.1 g/dL; p=0.03) and the experimental groups A (9.3→8.5→8.3 g/dL; p=0.01) and B (9.9→7.6→7.3 g/dL; p=0.0008). At each stage of bone development, multiple factors act in a coordinated manner that leads to increased local metabolic processes, acting both on the process of bone resorption and bone repair. Healing processes are initiated within 24 hours in both studied groups and the control group; at 14 and 21 days the bone healing processes are compromised directly proportional to the administration manner and dose of bisphosphonates.