Isolation and characterization of fecal bacteria capable of 16 alpha-dehydroxylating corticoids.

For more than a decade it has been known that the fecal flora of humans and rats includes organisms capable of 16 alpha-dehydroxylating corticoids, but their identity has remained unknown. To isolate these organisms, Mueller-Hinton agar plates were seeded with fresh feces from Proteus-free rats and incubated anaerobically. On an average, 1 of every 35 colonies consisted of organisms synthesizing 16 alpha-dehydroxylase. Isolation of the individual colonies yielded two obligate anerobes, strains 144 and 146, which elaborated the enzyme. The steroid transformation could be attained by the microbial culture alone in prereduced media or in aerobic media in the presence of Escherichia coli. Although both strains were phenotypically similar to Eubacterium lentum, they differed between themselves in their enzymatic equipment.     

Bacterial metabolism of corticoids with particular reference to the 21-dehydroxylation.

Clostridium paraputrificum, an obligate anaerobe recovered from human feces, reduces the alpha,beta-unsaturated carbonyl of deoxycorticosterone, corticosterone, cortisone, and cortisol. The same steroids are 21-dehydroxylated by Culture 116, recently isolated from human feces, and by a closely related organism, Eubacterium lentum. The 21-dehydroxylase has no effect on hydroxyl groups at carbon atoms 11 and 17.     

Isolation and characterization of human fecal bacteria capable of 21-dehydroxylating corticoids.

It has been known for a decade that human intestinal flora include organisms capable of 21-dehydroxylating corticoids. Yet the identity of the organisms synthesizing 21-dehydroxylase has remained unknown. Using diluted human feces, we determined the prevalence of colonies of 21-dehydroxylating organisms on a variety of media. Isolation from the medium of colonies with the highest prevalence yielded an obligate anaerobe capable of 21-dehydroxylating deoxycorticosterone and tetrahydrodeoxycorticosterone. This transformation could be carried out in a prereduced medium by the microbial culture alone or in an aerobic medium reduced by growth of Escherichia coli. The culture shares many characteristics with Eubacterium lentum, the neotype strain of which elaborated both 21-dehydroxylase and 3alpha-hydroxysteroid dehydrogenase.     

Plasma corticoids and brain tryptophan after acute and tolerance dosage of LSD.

The effect of acute and tolerance dosage schedules of LSD on plasma corticoids and brain tryptophan in normal, adrenalectomized and hypophysectomized rats was examined. Plasma corticoids increased 20-fold after one dose of LSD and the time course of this effect paralleled the increase in brain tryptophan. Both effects of LSD were abolished in adrenalectomized animals; after hypophysectomy the drug-induced tryptophan increase did occur but only after a significant delay. After multiple daily injections of LSD there was a significant degree of tolerance both to the plasma corticoid and brain trytophan response.     

Inhibitory effect of corticoids on the proliferative pattern in mouse palatal processes.

The formation of the secondary palate in mice is accompanied by intensive mitotic activity, which is mainly concentrated at the medial edges of the palatal processes. In control H-Velaz randombred fetuses the mitotic activity culminated approximately 24 h before palatal-shelf horizontalization, so that the period of intensive cell proliferation coincided with the period when cleft palate could be induced by cortisone administration. Effects of teratogenic doses of corticoids, injected directly into amniotic sac of embryos on day 13 (0.3 mg hydrocortisone) or im to pregnant females on day 12 (7.5 mg cortisone acetate), on the proliferative peak in palatal processes were studied using intraamniotic injection of colchicine. Counts of colchicine-blocked mitoses in histological serial sections revealed both a significant decrease in overall mitotic density and a posterior shift of the proliferative peak in the palatal processes of fetuses treated with doses of corticoids producing cleft palate.     

Isolation and characterization of human fecal bacteria capable of 21-dehydroxylating corticoids.

It has been known for a decade that human intestinal flora include organisms capable of 21-dehydroxylating corticoids. Yet the identity of the organisms synthesizing 21-dehydroxylase has remained unknown. Using diluted human feces, we determined the prevalence of colonies of 21-dehydroxylating organisms on a variety of media. Isolation from the medium of colonies with the highest prevalence yielded an obligate anaerobe capable of 21-dehydroxylating deoxycorticosterone and tetrahydrodeoxycorticosterone. This transformation could be carried out in a prereduced medium by the microbial culture alone or in an aerobic medium reduced by growth of Escherichia coli. The culture shares many characteristics with Eubacterium lentum, the neotype strain of which elaborated both 21-dehydroxylase and 3alpha-hydroxysteroid dehydrogenase.