Six patients were admitted after erroneous massive intake of levothyroxine (70-1200 mg over an interval of 2-12 days). All patients developed classical symptoms of thyrotoxicosis within 3 days of the first dose; five patients presented grade II-III coma and one became stuporous (days 7-10). Two patients developed left ventricular failure and three had arrhythmias (days 8-11). Total thyroid hormone levels in serum on admission ranged 935-7728 nmol/l for T4 (TT4) and 23-399 nmol/l for T3 (TT3). All patients received treatment with hydrocortisone and Propranolol. Propylthiouracil was also given in 3 cases. Extractive techniques (charcoal haemoperfusion and/or plasmapheresis) were initiated 8-14 days after the first dose of L-T4. The plasma disappearance rate (K) of TT4 with plasmapheresis was 30 times higher, on average, than under standard medical treatment (M). Also, K of TT4 under haemoperfusion was about five times higher than K under M. K changes for TT3 were higher under haemoperfusion than under plasmapheresis. Furthermore, extractive procedures shortened the average half life of TT4, (from 106.5 +/- 44.6 to 59.7 +/- 20.2 h, p less than 0.05).

Plasma immunoreactive somatostatin (IRS) levels were measured fasting at 09.00 h in groups of adult individuals and children of different ages, as well as in pregnant women, in patients with pernicious anaemia documented to be achlorhydric, and in children with growth hormone deficiency.There was a gradual rise in the mean level of IRS from the third decade (mean 35.8 \ m=+-\3.8 pg/ml), which reached significance at the seventh (61.1 \ m=+-\8.4 pg/ml), eighth (66.7 \ m=+-\ 5 pg/ml) and ninth decade (82.6 \ m=+-\ 13.8 pg/ml). No change was observed in the second 28.3 \ m=+-\ 3.8 pg/ml) and third (31.1 \m=+-\ 3.2pg/ml) trimester of pregnancy when compared with matched, non-pregnant controls (29.7 \ m=+-\ 2.2 pg/ml); however, the children aged under 2 years (69.6 \ m=+-\11.2 pg/ml) had significantly higher values than the eldest group (12 to 16 years old) (46.3 \ m=+-\7.2 pg/ml) (P < 0.05). In achlorhydric patients, basal (27.2 \m=+-\ 3.7 pg/ml; P < 0.01) and postprandial IRS (42.8 \ m=+-\ 7.7 pg/ml; P < 0.001) was significantly lower than in a matched, normal control group (basal 59.4 \m=+-\7.2; postprandial 132.1 \m=+-\26.3 pg/ml). Growth hormone deficiency was not associated with any differences in circulating IRS, basally or after insulin hypoglycaemia, when compared with values in normal children. These results would suggest, 1) that age has a significant effect on plasma IRS, and should be considered in the interpretation of fasting plasma levels of IRS; 2) that pregnancy and growth hormone deficiency is not accompanied by any changes in circulating IRS and presumably, somatostatin binding proteins; 3) that gastric acid is necessary for a normal release of IRS from the gastrointestinal tract to the circulation.

The main source of circulating immunoreactive somatostatin (IRS) seems to be the gastrointestinal tract. We therefore investigated plasma IRS in patients with various gastrointestinal diseases. Mean basal IRS oscillated between 46 and 73 pg/ml. A postprandial rise was observed in all patients and age-matched controls. However, the increment was significantly higher in patients with duodenal ulcer (159 +/- 20 pg/ml), active ulcerative colitis (176 +/- 17 pg/ml), and irritable bowel syndrome (194.4 +/- 20.4 pg/ml). Patients with duodenal ulcers who underwent vagotomy showed a decreased postprandial increment (107 +/- 10 pg/ml) when compared with active duodenal ulcer patients. No difference was demonstrable between controls and individuals with gastric ulcer, and patients with inactive ulcerative colitis. These results suggest that vagal innervation plays a role in postprandial IRS stimulation, whereas gastric hyperacidity, acute lesions of the colonic mucosa, and hypermotility of the gastrointestinal tract are associated with an exaggerated postprandial IRS response. Since somatostatin is known to influence many gastrointestinal functions, these variations in circulating IRS concentrations may be of pathophysiologic importance.

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