Influence of renal functional mass on the catabolism of endogenous gastrin in humans.

The influences of renal function and mass on the catabolism of serum gastrin were studied in 27 patients with hypertension caused by unilateral parenchymal renal disease (77.8%), renal artery stenosis (11.1%) and essential hypertension (11.1%). Blood for gastrin analysis was taken by catheterization from the aorta, inferior vena cava, renal veins and cubital vein. Separate renal functions were measured using radioisotope methods and the renal mass was also calculated. Significant differences (p < 0.001) in serum gastrin concentration between the aorta (29.5 +/- 6.7 pmol/l), inferior vena cava (23.4 +/- 5.8 pmol/l) and cubital vein (19.4 +/- 4.5 pmol/l) were found. Extrarenal gastrin extraction amounted to 12.5% and was considerably lower than renal gastrin extraction (20.5%). There was a significant positive correlation between renal gastrin extraction and renal blood flow or renal functional mass. Kidneys have an important, but not exclusive, role in the catabolism of endogenous gastrin in humans. In the catabolism of some, or at least some molecular forms of, gastrin, the capillary systems of extrarenal tissues have an important role.

[The effect of degree of renal function damage on the levels of serum gastrin and gastric acid secretion]. / Utjecaj stupnja ostecenja bubreznih funkcija na koncentraciju gastrina u serumu i sekreciju zelucane kiseline.

Fasting serum gastrin concentrations and both basal and maximum-stimulated gastric acid secretory rates have been studied in 225 patients with various degrees of impairment of renal function and 42 healthy subjects. Basal gastrin concentrations in the chronic renal failure (CRF) patients were significantly higher (p < 0.05) than in control subjects. When the glomerular filtration rate (GFR) was used as an index of the degree of renal impairment serum gastrin rose proportionately with the degree of renal failure. Basal (BAO), maximal (MAO) and peak acid output (PAO) in the CRF patients were significantly lower (p < 0.05) than in the control group. Both in the basal condition and during pentagastrin stimulation the CRF patients had low volume of gastric secretion. There was significant positive correlation between basal serum gastrin concentrations and the severity of renal damage. The basal serum gastrin concentration was inversely related to BAO, MAO and PAO in the CRF patients with severe impairment of renal functions. The results indicate that hypergastrinemia in CRF patients might be due to a combined effect of impaired renal catabolism of gastrin and overproduction of gastrin associated with hypochlorhydria. The present findings suggest that in CRF there are some unknown mechanisms that inhibit gastric secretion.

The possibilities of scintigraphic visualization of surfactants in the lung of the rat.

Incorporation of radioactive iodine into the surfactant system of the rat lung has been studied. Specially prepared particles labelled by 125I-oleic acid or 131I-oleic acid were injected intravenously and the distribution of radioiodine in the body of the animals was observed at various time intervals by means of a gamma camera and a gamma counter. The results showing appreciable accumulation of isotope in the lungs and the surfactant phospholipids, constitute a basis for the development of a new scintigraphic method for studying metabolic functions and morphology of the lung.