Possible Interaction: Acetylcholine and Secretin

“Application … secretin , forskolin (an adenylate cyclase activator), or PMA (a PKC activator) alone did not … any [Ca2+]c rise or zymogen granule exocytosis, but co-stimulation with ACh led to exocytosis in that the total number of secreted granules increased markedly without a significant difference in [Ca2+]c rises.”

“… secretin … ACh , and this was prevented by cyclosporin A. The effects of ACh were blocked by 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), 5-nitro2-(… acid (NPPB), or diphenylamine-2-carboxylic acid (DPC), and the effects of secretin were inhibited by NPPB or DPC and unaffected by DIDS.”

“ ACh did not influence the basal activity of the Cl-/HCO3- exchanger, but enhanced the stimulation by secretin of this anion exchanger by a Ca2+-dependent, protein kinase C-insensitive pathway that potentiates the secretin stimulation of adenylyl cyclase.”

“Intracellular cAMP levels, in isolated rat cholangiocytes, were unaffected by ACh alone, but were markedly higher after exposure to secretin plus ACh compared with secretin alone (P < 0.01).”

“When IBDU … exposed to ACh … secretin , ACh significantly (P < 0.03) increased the maximal rate of alkalinization after Cl- removal and the maximal rate of recovery after Cl- … compared with secretin alone (50 nM), indicating that ACh potentiates the stimulatory effect of secretin on the Cl-/HCO3- exchanger activity.”

“Applying secretin and ACh simultaneously to ducts caused either a stimulation or an inhibition of fluid secretion depending on the doses employed.”

“We conclude that the inhibitory effect of combined doses of secretin and ACh on ductal fluid secretion is probably mediated by PKC at a point in the secretory mechanism distal to the generation of intracellular messengers.”

“Combining either EFS or ACh with secretin resulted in an attenuation in amylase output compared with the response obtained with either EFS or ACh alone.”

“When ACh (10(−5) M) was combined with secretin there was an initial increase in [Mg2+]i followed by a marked decrease to the pre‐secretin‐stimulated value.”

“Incubation of cells with secretin increased the norepinephrine secretion resulting from stimulation by acetylcholine , but not from high potassium depolarization.”

“Acetylcholine, dibutyryl cAMP and secretin stimulated radioactive incorporation into both gastric mucin and non-mucin components with acetylcholine and dcAMP stimulating specifically [3H] glucosamine into gastric mucin.”

“The responses were potentiated in the presence of secretin (1 C.H.R.u./ml), but were suppressed in the presence of acetylcholine (10(-6) M) or in a Ca-free solution containing EGTA (10(-4) M).”

“During secretion induced by secretin both acetylcholine and papaverine caused an increase in the rate of secretion and both drugs also increased the rate of blood flow.”