[Silent myocardial ischemia and exercise-induced arrhythmia detected by the exercise test in the total health promotion plan (THP)].

We investigated the prevalence and characteristics of ischemic heart disease especially silent myocardial ischemia (SMI) and arrhythmia in need of careful observation in the exercise stress tests in the Total Health Promotion Plan (THP), which was conducted between 1994-96 for the purpose of measuring cardiopulmonary function. All workers (n = 4,918, 4,426 males) aged 18-60 yr old in an occupational field were studied. Exercise tests with an ergometer were performed by the LOPS protocol, in which the maximal workload was set up as a presumed 70-80% maximal oxygen intake, or STEP (original multistage protocol). ECG changes were evaluated with a CC5 lead. Two hundred and fifteen people refused the study because of a common cold, lumbago and so on. Of 4,703 subjects, 17 with abnormal rest ECG and 19 with probable anginal pain were excluded from the exercise tests. Of 4,667 who underwent the exercise test, 37 (0.79%) had ischemic ECG change, and 155 (3.32%) had striking arrhythmia. These 228 subjects then did a treadmill exercise test with Bruce protocol. Twenty-two (0.47% of 4,703) showed positive ECG change, 9 (0.19%) of 22 had abnormal findings on a 201Tl scan. 8 (0.17%) were diagnosed as SMI (Cohn I), in which the prevalence of hypertension, hyperlipidemia, diabetes mellitus, smoker and positive familial history of ischemic heart disease was greater than that of all subjects. In a 15-30 month follow up, none has developed cardiac accidents. Exercise-induced arrhythmia was detected in 11 (0.23%) subjects. Four were non-sustained ventricular tachycardia without any organic disease, 4 were ventricular arrhythmia based on cardiomyopathy detected by echocardiography, 2 were atrial fibrillation and another was WPW syndrome. It is therefore likely that the ergometer exercise test in THP was effective in preventing sudden death caused by ischemic heart disease or striking arrhythmia.

The role of diferric transferrin in iron absorption and transferrin concentration in rat pancreatic juice and milk.

Transferrin (Tf) was found immunologically in pancreatic juice of normal rats at a concentration of 0.28 +/- 0.10 mg/ml but was found to be approximately 4-times higher in iron-deficient rats. Iron saturation of pancreatic Tf of normal rats was 40% and similar to that of serum Tf. Approximately 27% of a dose of iron from 59Fe-diferric Tf was absorbed through the ligated segments of proximal intestine in normal rats. The iron absorption ratio of 59Fe-diferric Tf was higher from the duodenal and jejunal segments than the ileum and significantly inhibited by monodansylcadaverine (MDC) or 20-times excess of unlabeled diferric Tf. The presence of Tf receptors was demonstrated by specific binding of 125I-diferric Tf to the brush border membrane vesicles of the small intestine in normal rats. The binding was not inhibited by the presence of albumin or IgG. The association constant (Ka) was 1.03 +/- 0.50 x 10(8) M-1 and number of binding sites was 5.10 +/- 0.96 x 10(12) sites/mg protein in the proximal intestine. The number of binding sites for Tf was higher in the proximal intestine than in the distal one. These results suggested that some iron was absorbed as diferric Tf into enterocytes through receptor-mediated endocytosis.

[Detection of transferrin in the digestive juices of rat and its possible role in iron absorption from the small intestine].

Presence of transferrin in digestive juices and its possible role in iron absorption of rats were examined. Transferrin concentrations in saliva, bile, pancreas juice and intestinal fluid obtained from adult rats of the Wistar strain were measured by Rocket immunoelectrophoretic assay. Transferrin concentration in pancreas juice was the highest (approximately 0.28 mg/ml) in the collected digestive juices and the concentration in iron deficient rats was 4 times higher than that of normal rats. The iron saturation rate of transferrin in pancreas juice was approximately 40%. The participation of transferrin in iron absorption was investigated by the absorption through the intestinal segment of rats, into which 59Fe labeled diferric transferrin was injected. The rate of iron absorption was more efficient in duodenal and proximal segments compared to the distal segment of the small intestine. The value was approximately 20% in the duodenal segment but less than 2% in the ileal segment. Iron absorption from diferric transferrin in the duodenal segment was inhibited by 1 mM monodansylcadaverine, the inhibitor of endocytosis, or addition of 20 times the normal amounts of nonradioactive transferrin in the test material. These data indicated that the process of iron absorption through diferric transferrin was not a passive phenomenon. Furthermore, one hour after the absorption of diferric 125I-labeled transferrin in the proximal segment of the small intestine, 125I-labeled transferrin was detected from the mucosal tissue of the segment, the luminal surface of which had been treated by 0.25% pronase E before the mucosal scraping.(ABSTRACT TRUNCATED AT 250 WORDS)