Effects of antidepressants on alcohol-induced gastric mucosal injury in rats.

The purpose of the present report is to study the effects of antidepressants such as trimipramine, amitriptyline, maprotiline and mianserin on severe gastric mucosal lesions produced by ethanol in comparison with cimetidine (H2-antihistamine) and dexchlorepheniramine (H2-antihistamine). The percentage of macroscopic mucosal lesions caused by alcohol affects 15% of the mucosal area. But pretreated with cimetidine the affected area was 9.18%, with dexchlorepheniramine 5.01%, with trimipramine 14.46%, with amitripytline 7.94%, with maprotiline 3.8%, and with mianserin 4.07%. Microscopic evaluation reveals that ethanol produces destruction of glandular cells and injures medial and basal layers. All drugs used previously to ethanol produce a decrease of microscopical lesions. A direct relation was found between micro and macroscopical lesions in rats treated with maprotiline, mianserin and dexchlorepheniramine.

[Giant retroperitoneal liposarcoma]. / Liposarcoma retroperitoneal gigante.

Liposarcoma is a malignant tumor that has an embryologic origin from mesodermal tissue depending on fatty tissue. Although liposarcoma is only 0.1% of all human neoplasms, it is the most common histology subtype of retroperitoneal soft tissue sarcomas. This tumor grows slowly. Diffuse abdominal pain is its most frequent symptom and abdominal mass is the most common sign. Aggressive surgical treatment is basic to get a complete resection and a local disease control. This objective is difficult because of the large tumor size it gets in the retroperitoneal location and the multiorgan involvement that require the resection of a high percentage of contiguous organs. We report a case of a giant retroperitoneal liposarcoma presenting like continuous left hemiabdominal pain because of the visceral compression. The right kidney was involved and suffering from renal vessel enlargement without renal function. There is a high probability of microscopic residual disease and a good follow-up of the patients is necessary as well as an adjuvant radiation therapy in some cases.

The role of the neurotransmitters acetylcholine and noradrenaline in the pathogenesis of stress ulcers.

1. Adrenergic and cholinergic mechanisms seem to be involved in the pathogenesis of stress ulcers. 2. In this study, gastric ulcers were induced in rats by immobilization and cold. Prior intraperitoneal administration of both anticholinergic (atropine) as well as alpha-blocking medication (phenoxybenzamine) produced a very significant decrease in stress ulcers. 3. Additionally, using the technique of continuous intravenous perfusion in rats, acetylcholine was shown to have a gastric ulcerogenic effect, in contrast to noradrenaline. 4. It is concluded that acetylcholine is the peripheral mediator in stress ulcers, while noradrenaline intervenes at the encephalic level in stress ulcer pathogenesis.

Effect of 4-aminopyridine and 3,4-diaminopyridine on guinea-pig isolated ileum.

1. 4-Aminopyridine and 3,4-diaminopyridine produced concentration-dependent contraction on guinea-pig isolated ileum incubated in Tyrode solution. The EC30 values were 1.14 x 10(-4) and 1.39 x 10(-4) M, respectively. 2. Calcium channel blockers such as verapamil, diltiazem, nifedipine, flunarizine, and lanthanum chloride antagonized the contracting effect induced by 4-aminopyridine and 3,4-diaminopyridine in guinea-pig isolated ileum. 3. Diazoxide and atropine sulphate behaved similarly as antagonists of the contracting effect induced by 4-aminopyridine and 3,4-diaminopyridine in guinea-pig isolated ileum. 4. It is concluded that the aminopyridines exert their effects through the release of acetylcholine from parasympathetic nerve terminals.