Effect of ablation of capsaicin-sensitive neurons on gastric protection by honey and sucralfate

BACKGROUND/AIMS: Accumulating evidence indicates that capsaicin-sensitive afferent neurons play a pivotal role in acute gastroprotection by liberating vasodilator substances. The mechanism of gastric protection by honey and sucralfate has been shown to be mediated through the vasodilator nitric oxide and cytoprotective sulphydryl-sensitive pathways in the stomach. The aim of the present study was to investigate the role of capsaicin-sensitive afferent neurons in the protective mechanism of honey and sucralfate against ethanol-induced gastric lesions. METHODOLOGY: Ablation of capsaicin-sensitive afferent neurons was carried out by treating rats with neurotoxic doses of capsaicin (50 + 50 mg/kg subcutaneously over 2 consecutive days). The control groups received equal volumes of the vehicle (10% ethanol + 10% Tween 80 + 80% normal saline). The non-protein sulphydryl level was determined spectrophotometrically. RESULTS: Afferent sensory nerve ablation significantly aggravated ethanol-induced gastric lesions and caused a greater depletion of non-protein sulphydryl levels. Pretreatment with honey (0.078-0.625 g/kg, orally) or sucralfate (0.062-0.250 g/kg, orally) 30 min before administration of the ethanol prevented ethanol-induced gastric lesions and the depletion of non-protein sulphydryls in vehicle-treated rats. However, honey failed to afford protection or reverse non-protein sulphydryl depletion, while sucralfate was effective in the capsaicin-treated animals. The protective effect of sucralfate was lost in both groups following pretreatment with indomethacin (10 mg/kg, subcutaneously), while honey-induced protection was unaffected. CONCLUSIONS: These results suggest that the gastric protection by honey is solely dependent on the presence of intact afferent sensory neurons, whereas sucralfate-induced gastroprotection is mediated through the afferent sensory neuron and prostaglandin systems. It seems that the non-protein sulphydryl level is affected by the ablation of sensory neurons and plays an important regulatory role in gastric protection.     

Possiblity of using immobilized urease for degradation of urea in blood plasma

As revealed the velocities of urea decomposition in the citrate donor plasma with soluble urease and urease immobilized by addition to carboxymethyl ester of cellulose, 2-(3'-amino-4'-methoxyphenyl)-sulphonylethyl ester of cellulose, diethylaminoester of cellulose, stained with dichlortriazine stain, or graft copolymere of cellulose and polyglycidylmetacrylate were sufficiently close to one another. Preparations of immobilized urease can be repeatedly used for urea decomposition in the citrate donor blood. Periodical treatment of the mentioned preparations with cystein solution led to a lesser decrease of enzymatic activity of the immobilized urease after repeated use.     

Phakomatous choristoma of lower eyelid. A lenticular anlage tumour

A female infant was found to have a congenital, firm, pea-sized tumour nasally in the lower left eyelid. A dermoid cyst was suspected, but microscopy showed structures simulating a lens. The tumour has been considered to have an origin in surface ectoderm induced to dip down into the mesoderm of the lid, there forming lenticular anlage structures. This so-called phakomatous choristoma has only been reported five times previously, all cases outside Europe.