Studies on intestinal amino acid transport in the rat: effects of tetracycline and calcium – vitamin D deprivation

Tetracycline has been shown to inhibit protein synthesis in rat intestinal rings in vitro four hours after intraperitoneal administration. An inhibitory effect on the uptake of L-Iysine. L-alanine and cycloleucine was evidenced only at twelve hours after drug administration. Kinetic studies over time and concentration indicated reduced influx and Vmax. The findings suggest that a transport protein(s) which turns over rapidly becomes reduced in amount and rate limiting