Possible Interaction: Oxytocin and Tetrodotoxin

“ OT increased colonic smooth muscle contraction in both KO and WT mice, and the effects were blocked by OT receptor antagonist and tetrodotoxin but not by hexamethonium or atropine.”

“ Tetrodotoxin completely blocked the effects of oxytocin , demonstrating the network origin of the responses.”

“Atosiban and tetrodotoxin inhibited the effect of oxytocin on colonic motility.”

“The oxytocin current was inhibited by oxytocin-receptor antagonist, intracellular GDPβS, U-73122, 2-aminoethoxydiphenyl borate, but not dantrolene, chelerythrine, dibutyryl cyclic-AMP, CNQX, Ca(2+)-free and tetrodotoxin, while the spontaneous inhibitory transmission enhancements were depressed by tetrodotoxin.”

“The inhibitory effect of OT on duodenal motility was reversed by pretreatment of atosiban, lorglumide, or TTX.”

“Application of TTX to block action potential-dependent glutamate release inhibited the excitatory action of ET-1 in OT neurons.”

“Pretreatment of atosiban, the specific OTR antagonist, and TTX , the blocker of voltage-dependent sodium channel on nerve fiber, attenuated the excitatory effect of OT on colon motility.”

“The … of oxytocin were also totally inhibited by co-… with 5×10−8 mol/L tetrodotoxin (P <0.02) or 10−6 mol/L atropine (P <0.03) but not by 10−6 …/L hexamethonium, which implies that these effects are neurally mediated, primarily by intrinsic parasympathetic postganglionic neurons.”

“Inhibition of voltage-dependent Na+ channels by tetrodotoxin (1 microM) reduced the stimulation-evoked release of AVP and oxytocin ; however, the evoked release of ATP remained unaffected.”

“Basal plasma peptide levels were significantly reduced by TTX , e.g. decreases of 94.8 and 75.8% for VP and OT , respectively.”