Alteration of Hematologic Parameters in Morphine-Dependent Rats by Long-Term Administration of Orexin Type 1 Receptor Antagonist

Background: Orexin peptides that are produced in the hypothalamic nuclei are involved in opioid dependence. Objectives: In the current study, we aimed to figure out the effect of orexin type 1 receptor (OXR1) antagonist on hematologic factors in morphine-dependent rats. Patients and Methods: Male Wistar rats were rendered morphine-dependent by subcutaneous injection of morphine sulfate (10 mg/Kg) at an interval of 12 hours twice a day for seven days. In the control and treatment groups, SB-334867 vehicle and SB-334867 were injected during postnatal days 1 to 30 (P1-P30) daily and then before each morphine injection during for days. Data were analyzed using unpaired two-tailed Student t-test and one-way analysis of variance (ANOVA). The defined level of statistical significance was P < 0.05. Results: Morphine increased white blood cell count (WBC), platelet cell count, and hematocrit. Application of SB-334867 reduced several hematologic factors in morphine-dependent rats, including mean corpuscular hemoglobin concentration (MCHC), WBC, and platelet count compared to morphine-dependent rats. Conclusions: Inhibition of OXR1 may improve morphine-induced changes in hematologic factors in morphine-dependent rats.