Blood–Brain Transport of Thiamine Monophosphate in the Rat: A Kinetic Study In Vivo
Article first published online: 12 DEC 2006
Journal of Neurochemistry
Volume 50, Issue 1, pages 90–93, January 1988
How to Cite
Patnni, C., Reggiani, C., Laforenza, U. and Rindi, G. (1988), Blood–Brain Transport of Thiamine Monophosphate in the Rat: A Kinetic Study In Vivo. Journal of Neurochemistry, 50: 90–93. doi: 10.1111/j.1471-4159.1988.tb13234.x
- Issue published online: 12 DEC 2006
- Article first published online: 12 DEC 2006
- Received October 28, 1986; revised manuscript received July 2, 1987; accepted July 14, 1987.
- Thiamine monophosphate;
- Blood-brain barrier;
- Nervous system;
Abstract: To calculate the kinetic parameters of thiamine monophosphate transport across the rat blood-brain barrier in vivo, different doses of a [35S]thiamine monophosphate preparation with a specific activity of 14.8 mCi·mmol−1 were injected in the femoral vein and the radioactivity was measured in arterial femoral blood and in the cerebellum, cerebral cortex, pons, and medulla 20 s after the injection. This short experimental time was used to prevent thiamine monophosphate hydrolysis. Thiamine monophosphate was transported into the nervous tissue by a saturable mechanism. The maximal transport rate (Jmax) and the half-saturation concentration (Km) equaled 27–39 pmol·g−1·min−1 and 2.6–4.8 μM, respectively. When compared with that of thiamine, thiamine monophosphate transport seemed to be characterized by a lower affinity and a lower maximal influx rate. At physiological plasma concentrations, thiamine monophosphate transport rate ranged from 2.06 to 4.90 pmol·g−1· min−1, thus representing a significant component of thiamine supply to nervous tissue.