Chlortetracycline caused dramatic increases in intestinal weight of bacteria-laden and germ-free female mice only, the greatest in the former. Intestinal histamine and serotonin decreased in all mice ...

Antibiotics play an important role in controlling infectious disease. Many antibiotics used in clinical practice are naturally occurring, such that resistance to antibiotics among bacteria predates ...

In another study, reported by Sweeney and his associates, 2 demethylchlortetracycline was shown to be 25 per cent less active than chlortetracycline, but three times as active as either tetracycline ...