Insulin Infusion Normalizes Cardiovascular Responses and Plasma Noradrenaline after Oral Glucose in Type 1 (Insulin-dependent) Diabetes

ABSTRACT. We examined whether the abnormal regulation of the cardiovascular system and plasma noradrenaline observed after oral glucose in insulin-dependent diabetic patients could be normalized by intravenous infusion of insulin. Eight patients with type 1 (insulin-dependent) diabetes were examined after an oral glucose load with and without simultaneous infusion of insulin. Insulin infusion increased plasma insulin from 0.07 to 0.31 nmol/1. In the control experiment (glucose only), mean heart rate and mean arterial systolic blood pressure remained unchanged and plasma noradrenaline (NA) decreased (p < 0.05). After oral glucose plus intravenous insulin, mean heart rate increased by 11 % and mean systolic blood pressure by 5 % (p < 0.05, p < 0.01), whereas plasma NA did not change significantly. The present study indicates that physiologic increments in plasma insulin concentration are of importance in the regulation of the cardiovascular system and plasma NA following an oral glucose load.     

Some Investigations of Erythropoiesis in Human Bone-Marrow Cultivated in Various Media.

Experiments have been performed on human sternal marrow kept alive in vitro in Locke's solution with and without the addi-tion of different antipernicious anemia preparationsor of serum from either the same or from another person. These materials have been shown to maintain erythropoietic activity a t various levels. The slight formation of red cells which takes place in Locke's solution comes to a standstill after 8–10 hours, but is resumed later when red cells are hemolyzed and presumably liberate nutri-tive materials. Folk acid (0.1 yo) will increase the formation of red cells considerably and liver extract even more so. “Foreign” serum has about the same effect, but the subject's own serum causes most rapid erythropoiesis, thus pointing to the existence of a factor peculiar to each individual. A number of pathological cases were, investigated. The “spontaneous” production of the red cells was diminished in untreated pernicious anemia and leukemia, but was normal in various other conditions studied. I n most of the cases, the pathological inarrow responded quite as a normal marrow does when liver of folk acid is added to the nutrient fluid. Only in lymphogranulomatosis benigna was a significant decrease decrease below normal found in the product:on of red cells when these materials were used. Tyrosine increased the effect of liver extract in untreated pernicious anemia and in leukemia but had no added effect, on normal bone-marrow. The production of red cells from the pathological marrow nour- ished by normal serum is slightly decreased below normal in some of the pathological cases, especially in leukemia. I n this disease and in pernicious anemia there was a decreased total function of bone-marrow plus “native” serum. All pathological marrows, however, were considerably activated by the addition of normal serum to the nutrient fluid. The use of pathological serum with normal marrow results in a significant decrease in red cell produc-tion over that found when normal marrow is activated by “foreign” normal serum. In patients in whom a decrease was observed in the activity of the bone marrow cells and of the serum, i. e. in pernicious anemia, effective therapy resulted in an increase in the amount of those substances n both cells and serum which activate the formation of red blood cells in the marrow cultures. These results considered together with the results found in investigations of the ripening of the reticulocytes in vitro show that there are certain active principles in the serum, some being necessary for the production of red cells and some for the ripening of the reticulocytes. It appears that certain of these principles are necessary for both processes. I extend my deep gratitude to the Carlsberg Foundation and to the King Christian the Tenth Pund for supporting these in-vestigations.     

The porcine bronchial artery: surgical and angiographic anatomy

The pig is often used in experimental studies on the significance of bronchial artery circulation, but the anatomy of this artery is only poorly described. The purpose of this study was to improve the anatomical basis for experimental studies on the porcine bronchial artery circulation. The origin of the artery from the aorta is described in 32 pigs. Heart–lung blocks were perfused with saline and removed in 16 pigs, and the broncho-oesophageal orifice was identified and cannulated. In these 16 specimens the intrapulmonary ramification was studied by angiography, and the extrapulmonary distribution and supply area by injection of Evans Blue. The broncho-oesophageal artery originated from the aorta as a single trunk in 91%. Angiography showed that each principal bronchus was accompanied by 2 bronchial artery branches far into the lung parenchyma. The central branching pattern of the artery between the aorta and the principal bronchi was divided into 3 subtypes. Evans Blue showed communication with the whole mediastinum. The anatomical relations are described. It is concluded that the broncho-oesophageal artery divides to follow each bronchus with 2 bronchial branches. A nomenclature for these branches is suggested. The pig anatomy is suited for experimental investigations on the bronchial circulation.     

The effect of gastrin on basal and aminoacid-stimulated insulin and glucagon secretion in man

Abstract. The effect of gastrin on basal and aminoacid-stimulated glucagon and insulin secretion was studied in eleven normal young subjects. The concentrations of glucagon, insulin and gastrin in plasma or serum were measured radioimmunochemically. The results of amino-acid-stimulation were compared to those obtained during a protein-rich meal.
Intravenous injection of synthetic human gastrin-17 in doses from 15.6 ng to 1 μg/kg increased the concentration of glucagon and insulin in peripheral venous blood to a maximum within 5 min. In spite of the enhanced concentrations of insulin induced by gastrin, corresponding concentrations of glucose were either unchanged or increased. Infusion of a mixture of fifteen aminoacids increased the concentrations of glucose, glucagon and insulin. While the increases in glucose and insulin concentrations were similar to those obtained after a protein-rich meal, the glucagon response was much larger after the infusion. Injection of gastrin-17 after 30 min of infusion of aminoacids did not potentiate either the glucagon or the insulin response.
The results indicate that gastrin, besides stimulating insulin secretion, can also stimulate glucagon secretion in a dose-dependent manner. The concentrations of gastrin necessary to stimulate glucagon secretion significantly correspond to the concentrations found in diseases with endogenous hypergastrinaemia (achlorhydria and Zollinger-Ellison syndrome). While gastrin potentiates the glucose-induced insulin secretion, it does not potentiate neither the aminoacid-induced insulin nor glucagon secretion.