Traumatic hemobilia

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Extraction of circulating endogenous gastrin by the gastric fundus

The effect of circulatory transit of the gastric fundus on serum levels of endogenous gastrin measured directly by radioimmunoassay has been studied in 14 dogs. Gastrin was measured in samples obtained simultaneously from the arterial inflow and venous outflow of the gastric fundus. During basal conditions, transit of the gastric fundus resulted in no change in gastrin concentration. During periods of stimulated gastrin release from the antrum, nine of the 14 dogs demonstrated a significant gastric acid secretory response. In these dogs there was a significant arteriovenous difference (approximately 30%) in circulating gastrin values. In the remaining five dogs, which did not demonstrate a significant gastric acid secretory response, there was no arteriovenous difference in circulating gastrin values. It is concluded that the gastric fundus is an important site for the inactivation of stimulated levels of circulating gastrin.

Measurement of endogenous release of cholecystokinin by radioimmunoassay

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Effect of nephrectomy on the rate and pattern of the disappearance of exogenous gastrin in dogs

Studies of gastrin metabolism were performed in four dogs before and after nephrectomy. Synthetic human gastrin I was infused for two hours and serum samples were obtained at various times during and after infusion. Serum concentrations of gastrin were measured by radioimmunoassay. A two-compartment model was employed to calculate half-lives under each of four experimental conditions, low and high infusion rates, used both before and after nephrectomy. The model half-life was greatly prolonged after nephrectomy at both infusion rates (from 2.54 min to 5.15 min at the low rate, and from 2.85 min to 7.88 min at the high rate). The metabolic clearance rate, an expression of the rate of catabolism during infusion, decreased significantly after nephrectomy at both infusion rates. These observations indicate that the kidney is an important organ for the catabolism of exogenous gastrin.

The role of thoracic duct lymph in gastrin transport and gastric secretion

The effect of thoracic lymph diversion on gastric secretion has been studied in dogs. In addition, the concentration of gastrin in thoracic duct lymph of nine dogs and two patients has been measured before and during antral stimulation with either food or acetylcholine. The secretory studies do not support the concept that there is a significant gastric secretagogue in thoracic duct lymph. The amount of gastrin carried in thoracic duct lymph as determined by radioimmunoassay is far less than that necessary to evoke a gastric secretory response.

Correlation of the surface pH, histology, and gastrin concentration of gastric mucosa

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Comparison of the transfer RNA complements of chick embryos and their supporting membranes

The transfer RNA complement of 5- to 6-day chick embryos was compared with that of the associated membranes by chromatography of preparations of aminoacyl-tRNAs on columns of benzoylated diethyl-aminoethylcellulose. Profiles of all aminoacyl-tRNAs were determined under conditions selected for emphasis on the region containing a component believed to play a role in regulating onset of rapid hemoglobin synthesis in the blood islands of young blastodiscs. Differences in profile were observed only for alanyl- and glutamyl-tRNAs. A marked quantitative change in the distribution of components in the complement of glutamyl-tRNAs was in the converse direction of that required for increase in content of putative regulator and was not further investigated.Small reproducible differences in the profiles of alanyl-tRNAs were further investigated and were shown to be due to a marked increase in the content of a distinct minor component of the alanyl-tRNA complement of the membranes relative to that of the embryo.