It has been shown that when insulin is applied to chick embryos developing in vitro it induces a syndrome of abnormalities, the main features of which are an inhibition of brain and neural tube development at marginal concentrations and of mesodermal derivates at higher concentrations (Barron & McKenzie, 1962). These authors found that brain and neural-tube inhibition could be prevented by simultaneous administration of oxidized nicotinamide adenine dinucleotide, thus lending support to the hypothesis put forward by Landauer & Rhodes (1952) that insulin-induced anomalies are brought about by interference with oxidative phosphorylation of carbohydrates.
It has been suggested that one of the actions of insulin may be as an uncoupling agent in energy transfer (Randle & Smith, 1958a, b) and some support for this may be found in experiments carried out by Landauer & Clark (1964).
The effect of diclofenac sodium on neural tube development in the early stage of chick embryos