Guinea Pig Lung Diphosphopyridine Nucleotidase in Relation to Weight (Age)

Abstract

IN the course of experiments on the possible participation of diphosphopyridine nucleotide (DPN) and diphosphopyridine nucleotidase (DPNase, hydrolysing DPN at the nicotinamide–ribose link) in anaphylactic reactions in sensitized guinea pig lung, it was incidentally discovered that DPNase activity in lung varies with the weight of the animal. In early experiments it was noted that heavy guinea pigs (approximately 500–800 gm.) sensitized with bovine serum albumin consistently had high levels of DPNase activity in their lungs, whereas smaller animals had lower levels. These coarse observations led us to investigate the relation of lung DPNase activity to weight of animal. Since the weight of a guinea pig is approximately linearly related to its age, at least during the first 12 weeks of life, the data can be considered also in relation to age.