Large neutral amino acids levels in primate cerebrospinal fluid do not confirm competitive transport under baseline conditions.

In rodents, transport of large neutral amino acids (LNAAs) across the blood brain barrier (BBB) and blood-cerebrospinal fluid (CSF) barrier is mediated by high affinity carriers. Net brain LNAA levels are thought to be determined mainly by this competitive transport from plasma. Since the affinity for LNAA transport at the BBB in primates is considerably higher than in rodents, brain influx and by extension LNAA brain levels, should be even more dependent on competitive transport.

Implantable intrathecal pumps for chronic pain: highlights and updates.

Management of chronic pain by intrathecal delivery is gaining increasing use. The aim of this article is to review the literature pertinent to implantable devices used for treatment of chronic pain, and to highlight what is known. Articles were obtained from Medline database and reviewed.