A deficient response of atrial natriuretic peptide to volume overload in Gordon's syndrome.

Gordon's syndrome was diagnosed in a 19-year-old woman who had hypertension, hyperkalemia and hyperchloremic acidosis. In family screening, hyperkalemia and hyperchloremic acidosis were also found in the patient's mother and brother. The proband and her brother were studied and showed normal glomerular function with normal renal sodium conservation and urine acidification mechanisms. The levels of plasma aldosterone were normal in both subjects. The renin activity was low in the proband but normal in the brother. Both the basal and the volume-stimulated plasma concentration of atrial natriuretic peptide was low in the two patients. As compared with controls, the kaliuretic response to infusion of sodium chloride was not decreased in the patients. Hydrochlorothiazide promptly corrected the acidosis and the hyperkalemia as well as normalized the raised blood pressure of the proband. We suggest that a deficiency of atrial natriuretic peptide rather than an unusual avidity for sodium chloride reabsorption by the renal tubules plays a significant pathogenetic role in Gordon's syndrome.

Effects of the combination of insulin and glibenclamide in type 2 (non-insulin-dependent) diabetic patients with secondary failure to oral hypoglycaemic agents.

The effects of combined insulin and sulfonylurea therapy on glycaemic control and B-cell function was studied in 15 Type 2 (non-insulin-dependent) diabetic patients who had failed on treatment with oral hypoglycaemic agents. The patients were first treated with insulin alone for four months. Five patients were given two daily insulin doses and ten patients one dose. During insulin treatment the fasting plasma glucose fell from 14.5 +/- 0.8 to 8.8 +/- 0.4 mmol/l and the HbA1 concentration from 12.6 +/- 0.4 to 9.2 +/- 0.2%. This improvement of glycaemic control was associated with a suppression of basal (from 0.31 +/- 0.04 to 0.10 +/- 0.02 nmol/l) and glucagon-stimulated (from 0.50 +/- 0.08 to 0.19 +/- 0.04 nmol/l) C-peptide concentrations. Four months after starting insulin therapy the patients were randomised to a four-month double-blind cross-over treatment with insulin combined with either 15 mg glibenclamide per day or with placebo. Addition of glibenclamide to insulin resulted in a further reduction of the fasting plasma glucose (7.9 +/- 0.5 mmol/l) and HbA1 (8.3 +/- 0.2%) concentration whereas the basal (0.21 +/- 0.03 nmol/l) and glucagon-stimulated C-peptide concentrations (0.34 +/- 0.06 nmol/l) increased again. Addition of placebo to insulin had no effect. The daily insulin dose could be reduced by 25% after addition of glibenclamide to insulin, while it remained unchanged when insulin was combined with placebo. The fasting free insulin concentration did not differ between the glibenclamide and placebo periods (28 +/- 6 vs 30 +/- 5 mmol/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics and metabolic effects of glibenclamide and glipizide in type 2 diabetics.

Fifteen Type 2 diabetics were treated for 4-week periods with once daily (10 mg) glibenclamide, glipizide and placebo according to a double-blind cross-over protocol. Post-dose glipizide concentrations were three times higher than those of glibenclamide, due to the incomplete bioavailability of the latter. On the other hand, pre-dose drug levels were similar, as an expression of the slower absorption and/or elimination of glibenclamide. Both active treatments reduced postprandial blood glucose concentrations and 24-hour urinary glucose excretion to a similar degree, but fasting blood glucose concentrations were slightly lower during glibenclamide treatment. Both active treatments enhanced fasting and postprandial insulin and C-peptide concentrations, the C-peptide response being greater after glipizide than after glibenclamide. Plasma glucagon and GIP concentrations were not significantly affected. Insulin sensitivity was increased by glibenclamide but not by glipizide. Neither therapy affected insulin binding to erythrocytes. It appears that both glibenclamide and glipizide improved glucose metabolism by sustained stimulation of insulin secretion, which was most pronounced with glipizide. Only glibenclamide improved insulin sensitivity and was slightly more active than glipizide on fasting blood glucose levels. The differences may be consequences of the pharmacokinetics, but differences in pharmacodynamics cannot be excluded.

Arterial stenosis in renal transplantation.

Stenosis of the renal artery of the transplant (RAT), is reported with a frequency of 5-10% (Nerstrøm, Ladefoged & Lund 1972, Nilsson, Henriksson & Thoren 1976, Beachley, Pierce, Boykin & Lee 1976). The stenosis is significant if it deteriorates the renal function or elevates the arterial blood pressure. The angiographic impression of a stenosis depends on the projection and it is difficult to correlate the radiological findings with the blood flow. Moreover both renal failure and hypertension might depend on other factors than stenosis of the RAT. The aim of this study was to establish how often a reconstruction of a RAT suspected of being stenotic would benefit the patient.