A chemical called beta-guanidinopropionic acid blocks the creatine transporter in frog cells, and it takes about 44 millionths of a gram per milliliter to block half of the transporter's activity.
Scientific Claim
Beta-guanidinopropionic acid inhibits the human CRT-1 creatine transporter in Xenopus oocytes with an IC50 of approximately 44.4 microM, demonstrating its potency as an inhibitor in this experimental system.
Source Excerpt
“The induced uptake was inhibited by beta-guanidinopropionic acid (IC50 approximately 44.4 microM), 2-amino-1-imidazolidineacetic acid (cyclocreatine; IC50 approximately 369.8 microM), gamma-guanidinobutyric acid (IC50 approximately 697.9 microM), gamma-aminobutyric acid (IC50 approximately 6.47 mM), and amiloride (IC50 approximately 2.46 mM).”
Evidence from Studies
Supporting Studies
Molecular characterization of the human CRT-1 creatine transporter expressed in Xenopus oocytes.
The study directly measured the inhibition of creatine uptake by various compounds in Xenopus oocytes expressing the human CRT-1 transporter. The IC50 value quantifies the concentration needed for half-maximal inhibition in this specific experimental system.