Epithelium prostaglandin production

VP has a stimulatory effect on prostaglandin production in toad bladder , cultured renomedullary interstitial cells ", isolated CCT, and the Brattleboro rat26-2 negative feedback loop between VP and PG has been hypothesized but is not well established in all species studied. In toad bladder epithelium, for example, VP stimulates PG production by activation of phospholipase in a cAMP-independent manner the resultant increase in PG leads to inhibition of the hydro-osmotic effect of VP. A second negative feedback loop of cAMP-induced inhibition of prostaglandin synthesis may be present. 

The viscosity of mucus is affected by binding between calcium and the mucus, which probably arises from an ionic interaction with the sialic acid in the mucin. These variations are indicated by a change in the pH, viscoelastic properties, water, and protein content of cervical mucus. Calcium is needed to establish an intercellular contact and the assembly of tight junction in the cervical epithelium. Changes in extracellular calcium affect the permeability of tight junctions and play a role in regulating the production of cervical mucus.Prostaglandin concentrations... 

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