Effects of steroid hormones on Neisseria gonorrhoeae

Various steroids were tested for their effects upon gonococcal O2 consumption and glucose catabolism. The ability to inhibit gonococcal O2 uptake appeared to be related to the molecular configuration of the steroid. The presence of lipophilic groups enhanced inhibition, whereas the addition of hydrophilic groups markedly diminished inhibition. Steroid inhibition decreased with an increasing number of polar groups. Glucose catabolism was inhibited by steroid hormones, and the degree of inhibition was influenced by pH and medium composition. Changes in growth medium and pH also resulted in differential steroid inhibition of O2 uptake. Under certain conditions, lactate partially relieved this inhibition. Gonococci that were grown in one environment and shifted to a new environment were inhibited by steroids to the same extent as if they had been originally grown in the new environment. The differential effects of medium and pH upon steroid inhibition may be due to structural rearrangements involving membrane phase transitions or to altered receptor affinity.