Effect Of Non-Essential Amino-Acids On Fetal-Rat Pancreatic Growth And Insulin-Secretion Invitro

Fetal rat pancreatic rudiments explanted on day 14 of gestation were grown for 6 days in organ culture in medium containing glucose (5.5 or 16.5 mmol/l) and essential amino acids (3.5 or 13.1 mmol/l). Non-essential amino acids (alanine, aspartic acid, asparagine, glycine, proline and serine) were added to the culture medium in a number of combinations and at a maximum total concentration of 4.0 mmol/l. At the end of the period of culture rudiments were compared for DNA content, insulin concentration and quantitative morphology. The release of insulin from the rudiments was tested during 6-h incubations on day 6 of culture. Enrichment of the culture medium with any combination of non-essential amino acids had a slight or no effect on the growth or cellular composition of the rudiment of insulin release from it. Addition of all the non-essential amino acids to medium containing 16.5 mmol glucose and 13.1 mmol essential amino acids/l caused a dramatic reduction in the net insulin accumulation by the cultured rudiment. Combinations of non-essential amino acids in which one or more were omitted did not have the same effect. These findings suggest that fetal rat pancreas grown in vitro may require both essential and non-essential amino acids for the full expression of insulin biosynthesis and secretion.