Attenuation of prostaglandin E₂elimination across the mouse blood-brain barrier in lipopolysaccharide-induced inflammation and additive inhibitory effect of cefmetazole

• Main Authors: Akanuma Shin-ichi, Uchida Yasuo, Ohtsuki Sumio, Tachikawa Masanori, Terasaki Tetsuya, Hosoya Ken-ichi
• Format: Article
• Language: English
• Published: BMC 2011-10-01
• Series: Fluids and Barriers of the CNS
• Subjects: Blood-brain barrier; lipopolysaccharide; inflammation; multidrug resistance-associated protein; MRP4; Oat3; Oatp1a4; PGE₂; prostaglandin; transporter
• Online Access: http://www.fluidsbarrierscns.com/content/8/1/24

<p>Abstract</p> <p>Background</p> <p>Peripheral administration of lipopolysaccharide (LPS) induces inflammation and increases cerebral prostaglandin E₂(PGE₂) concentration. PGE₂is eliminated from brain across the blood-brain barrier (BBB) in mice, and this process is inhibited by intracerebral or intravenous pre-administration of anti-inflammatory drugs and antibiotics such as cefmetazole and cefazolin that inhibit multidrug resistance-associated protein 4 (Mrp4/Abcc4)-mediated PGE₂transport. The purpose of this study was to examine the effect of LPS-induced inflammation on PGE₂elimination from brain, and whether antibiotics further inhibit PGE₂elimination in LPS-treated mice.</p> <p>Methods</p> <p>[³H]PGE₂elimination across the BBB of intraperitoneally LPS-treated mice was assessed by the brain efflux index (BEI) method. Transporter protein amounts in brain capillaries were quantified by liquid chromatography-tandem mass spectrometry.</p> <p>Results</p> <p>The apparent elimination rate of [³H]PGE₂from brain was lower by 87%, in LPS-treated mice compared with saline-treated mice. The Mrp4 protein amount was unchanged in brain capillaries of LPS-treated mice compared with saline-treated mice, while the protein amounts of organic anion transporter 3 (Oat3/Slc22a8) and organic anion transporting polypeptide 1a4 (Oatp1a4/Slco1a4) were decreased by 26% and 39%, respectively. Either intracerebral or intravenous pre-administration of cefmetazole further inhibited PGE₂elimination in LPS-treated mice. However, intracerebral or intravenous pre-administration of cefazolin had little effect on PGE₂elimination in LPS-treated mice, or in LPS-untreated mice given Oat3 and Oatp1a4 inhibitors. These results indicate that peripheral administration of cefmetazole inhibits PGE₂elimination across the BBB in LPS-treated mice.</p> <p>Conclusion</p> <p>PGE₂elimination across the BBB is attenuated in an LPS-induced mouse model of inflammation. Peripheral administration of cefmetazole further inhibits PGE₂elimination in LPS-treated mice.</p>