Effect of somatostatin on neurotensin-induced glucagon release and hyperglycemia

Administration of neurotensin to dogs resulted in rises in circulating blood glucose, glucagon and insulin levels, the rise in glucagon being more pronounced than that in insulin. Infusion of somatostatin along with neurotensin suppressed glucagon and insulin responses to neurotensin and prevented the rise in blood glucose levels. These results suggest that the hyperglycemia seen after neurotensin is due to neurotensin stimulation of glucagon release over insulin release.

Malignant fibrous mesothelioma of the tunica vaginalis: a histologic and ultrastructural study

An unusual malignant fibrous tumor of the testicular tunic in a 35-year-old Japanese man is presented. It apparently arose from the visceral layer of the tunica vaginalis where focal mesothelial hyperplasia was seen. Microscopically the tumor consisted of interlacing bundles of spindle cells and numerous polygonal cells with variable amounts of collagen fibers. The electron microscopic study demonstrated the former cell type closely resembling the fibroblast and the latter to be more epithelial having very plump cytoplasm with fairly well developed desmosomes. The tumor was diagnosed as malignant fibrous mesothelioma upon histopathologic and ultrastructural comparison with the similar tumors in the pleura and peritoneum. Because of the scarcity of the diagnosis in the region it is suggested that fibrous paratesticular tumors are critically reviewed.

Release of proteins from the inner surface of squid axon membrane labeled with tritiated N-ethylmaleimide

Proteins in the inner surface of the squid axon membrane were labeled by intracellular perfusion of [3H]N-ethylmaleimide (NEM), which forms covalent bonds with free sulfhydryl groups. The excitability of the axon was unaffected by the [3H]NEM perfusion. After washout of the unbound label, the perfusate was monitored for the release of labeled proteins. Labeled proteins were released from the inner membrane surface by potassium depolarization of the axon only in the presence of external calcium ions. Replacement of the fluoride ion in the perfusion medium by various anions also caused labeled protein release. The order of effectiveness was SCN- greater than Br- greater than Cl- greater than F-. The extent of labeled protein release by the various anions was correlated with their effects on axonal excitability. The significance of these results is discussed.