Adenine nucleotide concentrations in A2-cell rich and normal pancreatic islets of the guinea pig.

Adenine nucleotides were measured in normal and A2-cell rich pancreatic islets of guinea pigs in order to evaluate the bioenergetic properties of the islet cells. The islets were either freshly isolated or cultured for one week. Immediately after isolation the ATP concentration of the normal islets was not significantly different from that of the A2-cell rich islets. Tissue culture raised the ATP concentrations in both experimental groups, leading to a significantly higher ATP content in the normal islets compared to the A2-cell rich islets. The total adenosine phosphate pool remained unchanged. Hypoxia for one minute markedly lowered the ATP concentrations in both normal and A2-cell rich islets. The ATP values could be normalized by renewed culture. The high interconversion rate of adenine nucleotides observed could provide the energy supply which may be required for fast changes in the hormonal secretions of both B- and A2-cells.