While there is an overlap in many instances between regulatory mechanisms in rodents and humans, there are some important differences. The only way to define which b -cell signalling systems identified in animal models are also operative in humans is to carry out the experiments using human islets. Through a collaboration with King's College Hospital, we are using islets of Langerhans isolated from human pancreata to determine the signal transduction cascades operative in human b -cells which regulate the exocytotic release of insulin. These studies are being performed by Henry Asare-Anane . Protein kinases, protein phosphorylation and the regulation of insulin secretion from pancreatic b -cells.
Tyrosine kinases play a permissive role in glucose-induced insulin secretion from adult rat islets.
The p38 mitogen-activated protein kinase cascade is not required for the stimulation of insulin secretion from rat islets of Langerhans. Gymnema sylvestre stimulates insulin release in vitro by increased membrane permeability. J. Endocrinol . Cyclic AMP-induced expression of steroidogenic acute regulatory protein is dependent upon phosphoprotein phosphatase activity. Phosphoprotein phosphatases regulate steroidogenesis by influencing StAR gene transcription.