Evaluation of creatine transport using Caco-2 monolayers as an in vitro model for intestinal absorption

✍ Scribed by Alekha K. Dash; Donald W. Miller; Han Huai-Yan; Joe Carnazzo; Jeffrey R. Stout

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 134 KB
• Volume: 90
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.1109

✦ Synopsis

Creatine is a nutraceutical that has gained popularity in both well-trained and casual athletes for its performance-enhancing or ergogenic properties. The major disadvantages of creatine monohydrate formulations are poor solubility and oral bioavailability. In the present study, creatine transport was examined using Caco-2 monolayers as an in vitro model for intestinal absorption. Con¯uent monolayers of Caco-2 cells (passage 25±35) were used for the permeability studies. Monolayers were placed in side-by-side diffusion chambers. 14 C-Creatine (0.1±0.5 mCi/mL) was added to either the apical or basolateral side, and the transport of the creatine across the Caco-2 monolayer was measured over a 90-min period. The apical to basolateral transport of 14 C-creatine was small, ranging from 0.2±3% of the original amount appearing on the receiver side in a 90-min period. Interestingly, the basolateral to apical permeability of radiolabeled creatine was substantially greater than that observed in the apical to basolateral direction. Studies with drug ef¯ux transport inhibitors indicate that neither the P-glycoprotein nor multidrug resistance-associated protein is involved in the enhanced basolateral to apical transport of creatine.