Figure 2

Angiotensin II protects DA neurons in vitro from MPP⁺ toxicity only in the presence of the AT₁ receptor antagonist losartan. (a) Microscopic view of TH⁺ (DA) neurons in VM cultures in the presence of media or MPP⁺ (10 μM) alone, MPP⁺ with Ang II (100 nM), and MPP⁺ with either losartan (1 μM) or PD123319 (1 μM). Scale bar equal to 50 μm. (b) Quantification of TH⁺ neuron counts in VM cultures treated with increasing concentrations of MPP⁺ (1–100 μM) in the presence or absence of Ang II (100 nM) and AT receptor antagonists, losartan (1 μM) (AT₁R) and/or PD123319 (1 μM) (AT₂R). Results are mean ± SEM. (n = 4–6). (*) Represents a significant difference (p ≤ 0.05, One-way ANOVA followed by Newman-Keuls post-hoc test) from MPP⁺.