p-Aminobenzoic acid (PABA) exerts three metabolic effects on E. coli: it acts as a normal vitamin at low concentrations, as a source of another vitamin, p-hydroxybenzoic acid (POB), at moderate concentrations, and as a growth inhibitor at high concentrations (150 to 1600 microg./ml.). The inhibition is competitively reversed by POB in 1/100 the concentration of PABA. The inhibition is also reve...

The proposed mechanism(s) associated with the inhibition of essential metabolic reactions by various compounds has received a great deal of attention in recent years, since antimetabolites have proved useful in several chemotherapeutic areas and in studying various metabolic reactions. The significance of p-aminobenzoic acid in microbial nutrition was first emphasized when Woods (1940) and Wood...

Background: Gibberellic acid (GBA) is a naturally occurring and commercially produced plant growth regulator which may cause a variety of effects including the stimulation of seed germination in some cases. Histochemical changes in testicular tissue including carbohydrates, lipids and alkaline phosphatase enzyme changes were evaluated. Materials and Methods: Twenty seven mature male rats after ...