Lennart Cegrell

Remarkable adrenergic nerves in the exocrine pancreas

SummaryThe adrenergic nerves in the pancreas of mice, rats, guinea-pigs, rabbits, and cats were investigated with the fluorescence method of Falck and Hillarp. The relations between the adrenergic fibres and the vessels were studied by the injection of india ink into the vessels.Besides the normal manifestation of adrenergic fibres at the large vessels, some vessels of capillary size were also accompanied by adrenergic fibres. These fibres had a very weak fluorescence, and showed up regularly only when the animal had been treated with Nialamide and L-DOPA or dopamine to increase the catecholamine content of the adrenergic fibres. The weakness of the fluorescence is perhaps due to low transmitter concentration or to small size of the nerve fibres, or to both. A rough estimate indicated that either the transmitter concentration of the nerve fibre is at least approximately 100 times below that seen in adrenergic nerves in other tissues, or that the radius of the varicosities of the nerve fibres is less than 0.2 μ. Neither alternative has previously been recognized.The secretory acini of the pancreas seem to lack a direct adrenergic supply. In the intrapancreatic ganglia, non-fluorescent nerve cells were reached by adrenergic terminals. No adrenergic nerve cells were detected in the pancreas of rats and cats. Small intensely fluorescent catecholamine-containing cells were observed in connexion with the intrapancreatic ganglia of rats.

Dopamine and 5-hydroxytryptamine in the guinea-pig pancreas☆

Abstract Quantitative and qualitative investigations have demonstrated the presence of noradrenaline and 5-hydroxytryptamine in the guinea-pig pancreas. In addition, dopamine was found in the fetal and newborn guinea-pig pancreas in widely varying amounts that could reach high levels. Prenatally and for some time after birth, the pancreatic dopamine and 5-hydroxytryptamine are stored in morphologically similar cells located in the islets or scattered among the exocrine acini. There is strong evidence that both these amines are stored concomitantly in some of these cells.

A Catecholamine storage in the pancreatic A2-cells of owl monkey (Aotes trivirgatus)

SummaryThe fluorescence method ofFalck andHillarp was used to study the occurrence of biogenic monoamines in the islets of Langerhans of monkeys. A storage of a catecholamine was demonstrated in the A2-cells of owl monkey, whereas no histochemically demonstrable amount of monoamines could be seen in the islet cells of marmoset,Rhesus monkey, squirrel monkey, andCebus monkey.

Dopa-decarboxylase and monoamine oxidase activities in a transplantable islet cell tumour of the golden hamster

In einem transplantierbaren Inselzelltumor des Goldhamsters, der neben 5-Hydroxytryptamin, Dopa und Dopamin eine bisher unidentifizierte, vermutlich monoaminähnliche Substanz enthält, wurde eine hohe Dopadecarboxylase- und Monoaminooxydaseaktivität gefunden. Nach Dopa-decarboxylasehemmung wurde eine starke Anhäufung von Dopa im Tumorgewebe beobachtet; dieser Befund weist auf eine schnelle Monoaminsynthese und einen schnellen Monoaminumsatz im Tumorgewebe hin.

Tyrosine hydroxylase activity in a transplantable islet cell tumour of golden hamster

In einem transplantierbaren Insel-zelltumor des Goldhamsters ist eine Tyrosinhydroxylase-Aktivität gefunden. Die hohe Aktivität der Enzyme zusammen mit einer starken Konzentration von Tyrosin deutet auf eine schnelle Synthese von Dopa in den Tumorzellen. Die Anwesenheit der Dopametaboliten DOPAC und HVA im Tumor wurde gezeigt.