Possible Interaction: Progesterone and Verapamil

“Synergy between the inhibitory effect of progesterone and the efflux pump inhibitors verapamil and 1-(1-naphthylmethyl)-piperazine is consistent with a role for efflux pumps in preventing progesterone-mediated inhibition of C. burnetii activity.”

“The calcium channel blocker verapamil (200 μM) completely inhibited the transient rise in [Ca2+]i produced by progesterone , but 100 μM verapamil had only a partial effect.”

“Since verapamil and progesterone are mutual inhibitors of P-glycoprotein ATPase stimulation in a non-competitive manner, these two molecules can also bind independently P-glycoprotein on separated sites.”

“This is confirmed here by the observation of a synergistic effect when mixtures of verapamil and progesterone are tested for the modulation of P-glycoprotein ATPase.”

“At high levels, progesterone and verapamil mutually enhanced each other's inhibitory action on the ATPase.”

“E and E+P increased the potency of verapamil Ca2+ antagonism but none of the treatments modified reserpine direct inhibitory effects.”

“As expected from their mutually non-exclusive interactions on P-gp, progesterone and verapamil when mixed induce a synergistic modulation of P-gp ATPase activity.”

“The ability of progesterone , GABA, or muscimol to stimulate exocytosis was blocked by the Ca2+ channel antagonists verapamil or nifedipine.”

“The calcium channel blocker, verapamil , also inhibited FPH-induced progesterone accumulation and GVDB in a dose-dependent manner, while having no effect on progesterone-induced meiotic resumption.”

“ Verapamil , an agent which inhibits cellular uptake of calcium, attenuated cyclic AMP and progesterone production by both cell groups at similar concentrations.”

“Although progesterone production was markedly increased by dibutyryl cyclic AMP, this was significantly lowered by an inhibitor of calcium uptake, verapamil.”