Insulin the simplest unicellular eukaryotes. Apart from animals, insulin-like proteins are also known to exist in the Fungi and Protista kingdoms. Insulin is produced by beta cells of the pancreatic islets in most vertebrates and by the Brockmann body in some teleost fish. Cone snails "Conus geographus" and "Conus tulipa", venomous sea snails that hunt small fish, use modified forms of insulin in their venom cocktails. The insulin toxin, closer in structure to fishes' than to snails' native insulin, slows down the prey fishes by lowering their blood glucose levels. The preproinsulin precursor of insulin is encoded by the "INS" gene.
Insulin resistance is a prominent change of metabolic conditions, under which the mother has to reduce her muscles' insulin sensitivity to spare more glucose for the brains (the mother's brain and the fetal brain). This can be achieved through raising the response threshold (i.e., postponing the onset of sensitivity) by secreting placental growth factor to interfere with the interaction between insulin receptor substrate (IRS) and PI3K, which is the essence of the so-called "adjustable threshold hypothesis" of insulin resistance. It is well known that insulin regulates the conversion of carbohydrates into fats (triglycerides) by promoting the absorption of, especially, glucose from the