The acute rise in plasma fibrinogen concentration with exercise is influenced by the G-453-A polymorphism of the beta-fibrinogen gene.

We have investigated the effects of chronic physical training and acute intensive exercise on plasma fibrinogen levels and the relationship of these responses to beta-fibrinogen G-453-A polymorphism genotype. One hundred fifty-six male British Army recruits were studied at the start of their 10-week basic training, which emphasizes physical fitness. Cohorts were restudied between 0.5 and 5 days after a major 2-day strenuous military exercise (ME) undertaken in their final week of training. Changes in fibrinogen concentration were adjusted for the effects of age, body mass index, and smoking history. Compared with baseline values, fibrinogen concentrations were significantly lower (11.9%, P=.04) at day 5 after ME, consistent with the beneficial effect of training. However, they were higher on days 1 through 3 after ME (suggesting an "acute-phase" response to strenuous exercise) and were maximal on days 1 and 2 (27.2%, P<.001 and 37.1%, P<.001 respectively). Fibrinogen genotype was available in 149 individuals. As expected from previous studies, men with one or more fibrinogen gene A-453 alleles had plasma fibrinogen concentration slightly but significantly higher at baseline (4.5%, P=.11). During the acute-phase response (days 2 and 3), however, the degree of rise was strongly related to the presence of the A allele, being 26.7+/-5.4% (mean+/-SE), 36.5+/-11.0%, and 89.2+/-30.7 for the GG, GA, and AA genotypes, respectively (P=.01). These results confirm that chronic exercise training lowers plasma fibrinogen levels, that intensive exercise generates an acute-phase rise in levels, and that this acute response is strongly influenced by the G/A polymorphism of the beta-fibrinogen gene.

Gamma-glutamyl Transferase Activity in Human Platelets: Quantification of Activity, Isoenzyme Characterization and Potential Clinical Relevance.

Gamma-glutamyltransferase (GGT) activity in human platelet sonicates was 13.6 u/g of protein (range: 7.9-25.0) in 13 healthy, non-smoking, female volunteers; corresponding values in 16 males were: 20.3 (10.1-26.0). These values Mered significantly (p = 0.034). Platelet and serum GGT activity correlated significantly (p > 0.04). Platelets seem to contain only the isoenzyme GGT 4. Part of this enzyme activity is in the form of aggregates or linked with membranes/proteins. This activity is released by Triton X-100 and trypsin and migrates as GGT 4. Serum GGT activity, a measurement in routine use, could be influenced by GGT released by platelets. It is therefore of interest that serum GGT activity can be increased in clinical conditions (e.g. myocardial infarction, diabetes, peripheral vascular disease) associated with platelet hyperactivity. Platelet GGT may influence intracellular S-nitrosoglutathione (a putative nitric oxide donor) levels. Potential associations between serum GGT activity and platelet function indices deserve investigation.

Spontaneous bile reflux in the elderly.

Duodenogastric bile reflux is common in postoperative stomach but has been reported in intact stomachs. Spontaneous bile reflux in the elderly has not been studied before. This has been assessed in dyspeptic elderly and young patients. Total bile acid (TBA) levels and pH were measured in the samples of fasting gastric juice. Antral biopsies were taken for histological examination including Helicobacter pylori identification. TBA levels were significantly higher in elderly patients with gastritis in comparison to elderly and young normal groups. Only 10% of elderly patients with gastritis and 7% with gastric ulcer has abnormal TBA (> 1 mmol/l). There was some correlation between the pH and TBA but a significant proportion of elderly patients has pH > 4 with a normal TBA. TBA levels were not significantly different in H. pylori +ve and H. pylori -ve patients. Nineteen elderly patients had evidence of reactive gastritis. Five of these patients had raised TBA levels with severe H. pylori infection. The remaining 15 patients had normal TBA. These patients were on NSAIDs and 4 of them had H. pylori infection. We conclude that spontaneous bile reflux in the elderly is uncommon. Hypochlorhydria which is observed in the elderly is not caused by alkaline bile reflux. The main cause of reactive gastritis in the elderly is NSAIDs ingestion.