The inter-conversion of hormonally active cortisol and inactive cortisone is catalyzed by 11β-hydroxysteroid dehydrogenase (11β-HSD). This conversion controls the level of active glucocorticoid concentration in tissues. As the fallopian tube plays a major role in the process of fertilization, we wanted to investigate whether 11β-HSD is present in the human fallopian tube to control the glucocorticoid levels as in other tissues.
Method of study
Isthmic, ampullary and fimbrial portions of the fallopian tube are obtained from patients undergoing hysterectomy and salpingo-oopherectomy for symptomatic leomyomata uteri. 11β-HSD activities were measured in the homogenates of the tube, cortisol as the steroid substrate. The enzyme activity was expressed as nanomolar cortisone formed per minute per gram of tissue (mean ± S.D.).
A significant level of 11β-HSD activity in oxidation direction was found in all three parts of the tube. There is no significant difference in the distribution of the enzyme activity throughout the tube. When tubal 11β-HSD activity was compared with endometrial histology, the enzyme activity is significantly lower in proliferative endometrium when compared with secretory endometrium (P = 0.002). The enzyme activity in inactive endometrium is significantly higher than the active endometrium (P = 0.05).
The presence of 11β-HSD throughout the fallopian tube and its correlation to endometrial histology is indicative of its probable role in controlling the glucocorticoid levels in the tissue, which in turn may influence the fertilization process.