Effects of oral calcium gluconate on gastric acid secretion and serum gastrin concentration in man

A single oral dose of 4-46 mmol calcium gluconate at pH 5-6 was administered intragastrically to 15 male volunteers without gastrointestinal disease. There was a significant rise in acid output from 30-90 minutes after the calcium was given compared with the basal hourly collection. The serum gastrin level 30 minutes after calcium administration was significantly raised, but no correlation could be demonstrated between the acid and gastrin responses. Serum calcium levels were unchanged throughout. An equimolar dose of magnesium sulphate had no such effects. This study suggests that the intragastric administration of calcium results in independent release of gastric acid and gastrin from the gastric mucosa.

The renal handling of insulin and thyroid hormones in normal man

1. The renal extraction of insulin and thyroid hormones T3 and T4 was studied in man by right renal vein catheterization. 2. The mean renal extraction of insulin was 0-46, suggesting that the right renal vein should be utilized in comparable studies. 3. No renal extraction of thyroid hormones was detected.

Elevation of serum gamma-glutamyl transpeptidase in end-stage chronic renal failure

The serum gamma-glutamyl transpeptidase (GGT) was measured on 32 randomly selected patients about to commence or already on chronic haemodialysis. Raised values were found in 12 patients (37%). None of these patients had received drugs known to affect hepatic microsomes and all had normal liver function tests. The possible significance of this surprising finding is discussed.

Changes of blood pressure, renin, and angiotensin after bilateral nephrectomy in patients with chronic renal failure

Circulating levels of renin, angiotensin I, and angiotensin II were increased in six patients with chronic renal failure and hypertension uncontrolled by dialysis and hypotensive drugs. Lower and often normal levels were found in 10 patients whose blood pressure was controlled by dialysis treatment. For a variety of reasons all patients were subjected to bilateral nephrectomy. The logarithm of the decrease in plasma concentrations of renin and angiotensin II was significantly related to the fall of blood pressure after operation. Plasma renin concentration correlated significantly with blood angiotensin I concentration and with plasma angiotensin II in samples taken before and after nephrectomy. Renin, angiotensin I, and angiotensin II were measurable in samples of blood taken 48 hours or more after the operation.