Pantothenic acid tissue uptake

Two biotin transporters have been described a multivitamin transporter present in many tissues and a biotin transporter identified in human lymphocytes. In 1997, Prasad and coworkers discovered a Na" "-coupled, saturable, structurally specific transporter present in human placental choriocarcinoma cells that can transport pantothenic acid, lipoic acid, and biotin. This sodium-dependent multivitamin transporter has been named SMVT and is widely expressed in human tissues. Studies by Said and coworkers using RNA interference specific for SMVT provide strong evidence that biotin uptake by Caco-2 and HepG2 cells occurs via SMVT thus, intestinal absorption and hepatic uptake are likely mediated by SMVT. The biotin transporter identified in lymphocytes is also Na coupled, saturable, and structurally specific. Studies by Zempleni and coworkers provide evidence in favor of monocarboxylate transporter-1 as the lymphocyte biotin transporter. 

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