Effect of extrinsic denervation on the rate of net water transport of the feline gall bladder

Relationship between gallbladder bile concentration and motility in conscious dogs: role of cholecystokinin

The relationship between gallbladder (GB) bile concentration and motility was studied in conscious dogs. The 12-h GB bile concentrations between meals could be divided into three periods: diluting, minimum, and concentrating periods. During the diluting period, inhibition of GB contractions by a CCKA receptor antagonist, atropine or hexamethonium, resulted in concentration of GB bile, whereas during the concentrating period, CCK-8 shifted the concentration process back to dilution. The GB appears to absorb water continuously from GB bile, which is not regulated by cholinergic or CCKA receptors. The postprandial progressive dilution of GB bile is brought about by GB pumping controlled by cholecystokinin (CCK).

Topical treatment of ulcerative proctitis with lidocaine

Rectal biopsy specimens from patients with ulcerative proctitis/proctosigmoiditis (UP/PS) were investigated immunocytochemically. In general, a changed mucosal innervation was demonstrated, with a marked increase in the number of nerve fibres and terminals with neuropeptide Y and tyrosine hydroxylase. In a few patients a hyperinnervation with VIPergic or SPergic nerves was seen. These findings indicate that hyperactive local nervous reflexes are of pathogenetic importance. To silence such activity, the diseased mucosa was treated with topically applied lidocaine. Such topical treatment with lidocaine gel in 21 consecutive patients with UP/PS for 3-8 weeks caused a rapid decrease of subjective and objective symptoms. During treatment mucosal integrity was restored, accompanied by depletion of OKT4 and OKT8 lymphocytes from the mucosa. However, the hyperinnervation pattern persisted during treatment.

Regulation of ion transport in porcine gallbladder: effects of VIP and norepinephrine

The objective of this study was to investigate the effects of vasoactive intestinal peptide (VIP) and norepinephrine (NE) on Na and Cl transport across the isolated porcine gallbladder. Serosal addition of either VIP or secretin increased the short-circuit current (Isc). The half-maximal effect for VIP was 84.3 nM. The effect of VIP was mimicked by 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP). Replacement of Cl with gluconate nearly abolished the effect of 8-BrcAMP on Isc, whereas HCO3 replacement with N-2-hydroxyethylpiperazine-N'-2-ethane-sulfonic acid buffer had no effect. Transepithelial flux measurements indicated that 8-BrcAMP stimulates net Cl secretion and inhibits Na absorption. Norepinephrine inhibits VIP-stimulated changes in Isc as well as the basal Isc. NE does not, however, reverse the effects of 8-BrcAMP on Isc. The effects of NE are antagonized by yohimbine (alpha 2-adrenergic receptor antagonist) but not prazosin (an alpha 1-adrenergic receptor antagonist). VIP causes a 2.5-fold increase in cAMP content in the gallbladder epithelium. This increase is blocked by NE. Serosal tetrodotoxin did not inhibit the peptide effects, indicating that VIP receptors are localized on the epithelium. Depolarization of submucosal nerves with veratrine inhibited the basal Isc and was reversible with yohimbine. This result indicated that sympathetic nerve pathways regulate Na and Cl absorption in vitro.