The biological activity of different gastrin peptides assessed using a cytochemical section bioassay

A cytochemical section bioassay has been used to assess the carbonic anhydrase activity, induced by the gastrin peptides G13, G17 and G34 (concentration 5.0-0.005 pg/ml), in guinea pig parietal cells. When the mean integrated density of the induced response x 100, was plotted against the concentration of the gastrin peptide used, a graded dose response and a positive linear correlation was found for G13 and G17. These responses were similar. G34 did not produce a linear dose response in the concentration range 5.0-0.005 pg/ml, but a higher overall carbonic anhydrase activity was observed than with G13 and G17.