Intramural pH of the gastric mucosa was measured using a microelectrode technique in rabbit gastric pouches under different secretory conditions and luminal acidity. Exposure of spontaneously secreting or metiamide-treated fundic pouches to a relatively high concentration of luminal acid. HCl 120 mM, for 60 min, led to a marked net loss of luminal H+ which was associated with a significant decrease in the intramural pH (7.28 +/- 0.09 to 6.88 +/- 0.10 and 7.23 +/- 0.07 to 6.99 +/- 0.09, respectively). A linear relationship was observed between the rates of net disappearance of luminal acid and the intramural pH. All 10 spontaneously secreting and five metiamide-treated pouches had superficial mucosal erosions. In contrast, when fundic pouches were exposed to luminal acid in histamine-treated animals, the net loss of luminal H+ was negligible and the intramural pH remained at its base-line level (7.25 +/- 0.07). Histamine stimulation without acid in the lumen caused a small but insignificant increase in the intramural pH (7.27 +/- 0.03 to 7.39 +/- 0.05). Only three of the eight histamine-treated fundic pouches had lesions. In the antral pouches the intramural pH changes in response to exposure to luminal acid were smaller and histamine treatment did not influence the intramural pH. None of the antral pouches had lesions. The results suggest that acidification of the tissue by the diffusion of luminal acid may be an important factor in the pathogenesis of acute gastric ulceration. The acid secretory state of the gastric mucosa can significantly influence the acid-base balance in the mucosa and thus modify its response to acid diffusing from the lumen. Histamine stimulation protected the gastric mucosa by improving its buffering capacity and/or otherwise decreasing the diffusion of H+ from the lumen into the mucosa.

Animals↗

PubMed1978

Treatment of idiopathic thrombocytopenic purpura in adults. Long-term results in a series of 41 patients.

The results of treatment of idiopathic thrombocytopenic purpura (ITP) were analysed in a series of 41 patients 2 to 10 years (median 4 years) after initial treatment. There was one spontaneous remission. A good or fair long-term result was obtained in 11 patients after prednisone treatment, in 20 of 24 patients after splenectomy, and in 3 of 4 patients after immunosuppressive treatment. Short duration of symptoms and rapid response to prednisone had some value in predicting a good long-term result of prednisone treatment. Young age, a good response to prednisone and splenic sequestration of platelets were associated with good results after splenectomy, as was rapid postoperative normalization of platelet counts. These factors were unable to disclose with certainty a refractoriness to splenectomy. Nevertheless splenectomy was regarded to be the treatment of choice in all patients not adequately controlled with corticosteroids.

Adult↗

PubMed1978

Effects of lysolecithin on isolated gastric mucosa.

The effects of lysolecithin, a normal constituent of duodenal juice, on gastric mucosa were measured under isolated conditions. In a relatively low concentration (0.5 mg/ml), lysolecithin, added to the luminal side, caused liberation of organic acids without altering the spontaneous rate of mineral (i.e., HCl) acid secretion by fundic mucosa. The low concentration of lysolecithin also did not appear to affect other active ion transport processes or permeability of either fundic or antral mucosa. However, at a higher concentration (1 mg/ml) lysolecithin inhibited spontaneous mineral acid secretion by fundus, altered active transport of other ions, and increased mucosal permeability of both fundic and antral mucosa. The results suggest that intraluminal lysolecithin in concentrations found in vivo may contribute to gastric mucosal damage.

Animals↗