BACTERIAL STEROIDOGENESIS BY PERIODONTAL PATHOGENS AND THE EFFECT OF BACTERIAL ENZYMES ON STEROID CONVERSIONS BY HUMAN GINGIVAL FIBROBLASTSIN CULTURE

Studies were performed to investigate the effect of microbial culture supernatants of periodontal pathogens on the metabolism of radiolabell ed testosterone in the presence or absence of human gingival fibroblas ts. Subgingival plaque samples were obtained on paper points from 3 si tes with probing depth values of 6-8 mm. Samples were incubated with 1 4C-testosterone for 24 h in brain heart infusion (BHI) broth. Similar incubations were also carried out with strains of A. actinomycetemcomi tans, P. Intermedius and P. gingivalis to study the metabolism of radi olabelled testosterone by these periodontal pathogens. At the end of a 24 h incubation period with fibroblasts and supernatants or sonicates , the radioactive metabolites were extracted with ethyl acetate, evapo rated and subjected to thin layer chromatography. The separated metabo lites were quantified by scanning the radioactive plates using a Berth old linear analyser. When three sub-gingival plaque samples were incub ated with radiolabelled testosterone there were 50-fold, 10-12-fold an d 15-17-fold increases in 5 alpha-dihydrotestosterone (DHT) synthesis over 4-androstenedione production in these mixed microbial cultures. T he two strains of P. intermedius produced 3- and 20-fold increases in 4-androstenedione production and DHT synthesis respectively. Both stra ins of A. actinomycetemcomitans and P. gingivalis showed 3-4-fold and 12-28-fold increases respectively in 4-androstenedione synthesis over that of DHT. Culture supernatants of P. intermedius and P. gingivalis caused 3-fold and 2-fold increases in DHT synthesis by fibroblasts ove r controls. There was little change in the case of the third pathogen. Since DHT has implications on matrix synthesis by fibroblasts in the environment of plaque associated inflammatory periodontal disease, bac terial metabolism and the effect of bacterial supernatants on human gi ngival fibroblasts can influence the degree of inflammatory repair.