AL-8810 ((5Z,13E)-(9S,11S,15R)-9,15-Dihydroxy-11- fluoro-15-(2-indanyl)-16,17,18,19,20-pentanor-5,13- prostadienoic acid) is a prostaglandin F2a analog and a selective FP prostanoid receptor antagonist. The mean antagonist potency (Ki) of AL–8810 at the FP prostanoid receptor in both 3T3 fibroblasts and A7r5 vascular smooth muscles cells was 400-500 nM. AL–8810 produced a concentration-dependent shift in the fluprostenol concentration-response curve, without significantly decreasing the maximal response, indicating that AL-8810 is a competitive antagonist. Al-8810 also exhibited similar antagonist potency in inhibiting fluprostenol-stimulated PLC activation in HEK-293 cells expressing the cloned human ocular FP receptor. In contrast, even at 10 mM concentration, AL-8810 did not significantly inhibit DP, EP2, EP4 and IP prostanoid receptors. In a preclinical study, the effect of acute intraperitoneal post-treatment with AL-8810 was studied in FP receptor knockout (FP-/-) mice after controlled cortical impact (CCI). Results showed that post-treatment with AL-8810 had no significant effect on cortical lesions, suggesting the irreversible effect of primary CCI injury, but significantly reduced hippocampal swelling. In addition, AL-8810 treatment at a dose of 10 mg/kg could significantly improve NDS after CCI, and in the AL-8810 group, CCI-induced decrease in grip strength was three-fold less. AL-8810 is a valuable tool for determining specific FP receptor-mediated functions in complex biological systems.