Presence of caerulein in extracts of the skin of Leptodactylus pentadactylus labyrinthicus and of Xenopus laevis

1. The South American amphibian Leptodactylus pentadactylus labyrinthicus and the South African amphibian Xenopus laevis contain in their skin a polypeptide indistinguishable from caerulein prepared from the Australian amphibian Hyla caerulea.2. The caerulein content of different batches of Leptodactylus pentadactylus labyrinthicus skins varies from 10 to 500-600 mug/g tissue. Drying of the skin causes either a moderate decrease or a slight increase in the caerulein content. Methanol extraction gives considerably higher yields of caerulein than acetone extraction.3. Caerulein or caerulein-like polypeptides also occur in the skin of several other species of Leptodactylus together with 5-hydroxyindole alkylamines and imidazole alkylamines. Yet other species of Leptodactylus lack caerulein-like polypeptides and 5-hydroxyindole alkylamines.4. It is suggested that caerulein and caerulein-like polypeptides may have some function either in the regulation of secretory processes of the skin or in the exchange of water and electrolytes through the skin, or in both.     

Uptake of 125I albumin by the endothelial surface of the isolated dog common carotid artery: effect of certain physical factors and metabolic inhibitors.

A study has been made, under transient conditions, of the uptake of 125I albumin by the endothelial surface of isolated dog carotid arteries. Effective rate constants were determined and the apparent activation energy was calculated to be about 13 kcal/mol in the range 25-37 degrees C. Label uptake was not significantly altered by the presence of 1 mmol/1 potassium cyanide or 10 mmol/1 iodoacetate in the incubating medium, or by the absence of substrate from it, consistent with the process being primarily passive. It appeared that the label entered the wall mainly by other routes than the endothelial inter-cell clefts.     

Forging e-health partnerships: strategic perspectives from international executives

International executives underscore the key management frontiers of strategic e-health partnerships between information and communication technology and health care sectors for innovative growth, systems integration, and social responsibility.