Possible Interaction: Progesterone and Triamcinolone

“Preincubation with a 100-fold excess of progesterone reversed the growth inhibition observed with triamcinolone acetonide but not dexamethasone acetate.”

“ Progesterone was found to displace 85% of labeled triamcinolone acetonide from the cytoplasmic receptor but no appreciable competition was found for 17β-estradiol or 5α-dihydrotestosterone (DHT).”

“A 500-fold excess of cortexolone or progesterone blocked the response of 10(-8) M TA by 42 and 38%, respectively, indicating that the glucocorticoid response could be inhibited by antiglucocorticoids.”

“When triamcinolone acetonide (30 μg/kg BW) or dexamethasone (125 or 150 μg/kg BW) was given as a single injection in combination with progesterone (100 μg/kg BW), estrous response to estradiol benzoate was again inhibited.”

“In this paper, we show that two other glucocorticoids, triamcinolone acetonide and hydrocortisone, also cause growth inhibition in RPMI 3460 cells and that progesterone can block this response.”

“Abstract Progesterone was found to exhibit antiglucocorticoid properties in rat thymocytes, as indicated by its ability to compete effectively for triamcinolone acetonide (TA) binding sites as well as to inhibit the biochemical effects of TA.”

“Additional binding of progesterone was observed in cells pre-saturated with TA.”

“In a cell free system, progesterone competitively inhibited the binding of TA to glucocorticoid-specific binding sites and was more effective than the antiglucocorticoid cortexolone in this respect.”

“ Progesterone at 10−7−10−6M antagonized the inhibitory effect of 5 × 10−8TA on RNA metabolism, although it was inactive by itself … an inhibitor of [3H]-uricline uptake and incorporation into thymocyte RNA; this antagonism was not due to competition by progesterone for TA uptake into the cells.”

“ Progesterone prevents the swelling of mitochondria by stilbestrol monomethyl ether and triamcinolone.”