Figure 3. Dose-dependent and time-course effects of morphine on AIDS virus replication.

A and C: Dose-dependent effect of morphine on HIV or SIV replication. Seven-day-cultured macrophages were treated with or without morphine at indicated concentrations for 24 h and then incubated with HIV Bal or SIV Delta_B670 strain for 2 h in the presence or absence of morphine. Day 6 culture supernatant was collected for HIV (A) or SIV (C) RT assay. B and D: Time-course effect of morphine on HIV or SIV. Seven-day-cultured macrophages were treated with or without morphine (10⁻¹⁰ M) for 24 h prior to infection with HIV Bal strain or SIV Delta_B670 strain for 2 h and then cultured for 15 days. HIV (B) or SIV (D) RT activity was determined in cultured supernatants at indicated time points postinfection. Data are expressed as HIV or SIV RT activity in morphine-treated cells (percentage of control) compared with those in untreated cells. The results represent the mean ± SD of three independent experiments using macrophages from three different donors. Statistical analysis was performed by one-way analysis of variance (A, C) or Student's t-test (B, D), and significance is shown morphine versus control with * (P<0.05) and ** (P<0.01).