Possible Interaction: Oxytocin and Progesterone

“Concentrations of progesterone , similar to those present in corpora lutea (approximately 30 microg/g), prevented the increased intracellular concentrations of calcium (P < 0.05) stimulated by oxytocin in small cells.”

“It was concluded that normal luteal concentrations of progesterone prevent the oxytocin and perhaps the PGF2alpha-induced increase in the number of small and large luteal cells which respond to these hormones with increased intracellular concentrations of calcium.”

“Until close to term the responsiveness of oxytocin neurons is restrained by neuroactive steroid metabolites of progesterone that potentiate GABA inhibitory mechanisms.”

“ Oxytocin applied to intact corpus luteum stimulates the secretion of progesterone and oestradiol.”

“The stimulation of progesterone secretion by oxytocin is due to the stimulated oestrogen production.”

“These findings add to the accumulating evidence indicating that OT administration modulates endogenous levels of several other hormones, such as progesterone , epinephrine, and alphaamylase, in humans.”

“In females, OT may, thus, enhance the detection of threatening stimuli in the environment, potentially by interacting with gonadal steroids, such as progesterone and estrogen.”

“ Oxytocin concentrations were correlated negatively with progesterone concentrations (Spearman's rank correlation coefficient r=−0.50; P=0.001).”

“ Oxytocin enhanced the effects of forskolin on progesterone production.”

“… progesterone inhibits ERalpha and HOXA10 expression, these findings indicate that myometrial progesterone responsiveness is inversely related … relative to PR-B. ERalpha mRNA levels correlated positively with cyclooxygenase type 2 and oxytocin receptor mRNA levels in nonlaboring myometrium, indicating that the … the activation of contraction-associated genes and estrogen responsiveness.”

“In vivo, oxytocin and prostaglandin F2 alpha(PGF2 alpha) stimulate estradiol and progesterone release and estradiol itself further stimulates progesterone release.”

“The higher concentration of progesterone (5 fig/mL) plus oxytocin and progesterone plus E2 elevated the tonus (P < .05 and P < .01), whereas progesterone in combination with E2 and oxytocin decreased it (P < .05).”