Nutritional Essentiality of Pyrroloquinoline Quinone

Abstract

A chemically defined diet, based on synthetic amino acids, was fed to rats and mice. The control diet (+PQQ) was fortified with pyrroloquinoline quinone (PQQ) at 875 ug/kg. The deficient diet (-PQQ) contained no detectable PQQ. The -PQQ diet was fed to pregnant rats and, in later experiments, to mice throughout gestation. Newborn pups remained with the dams and at weaning were assigned to either the +PQQ or -PQQ diet. In each case, weight reduction occurred in the -PQQ groups (30% for mice, 10–15% for rats). However, to observe this response, an antibiotic, succinyl sulfathiazole, was added to diets at 2%. Diets were autoclaved to reduce the potential for subsequent bacterial contamination, and animals were housed within a laminar flow hood in sterile stainless steel cages. Moreover, cage bottoms were designed to prevent coprophagy. Addition of PQQ to the diets of animals in the -PQQ group consistently stimulated growth. Important physiological responses to PQQ deprivation were a 40% reduction in tendon benzylamine oxidase and an increase in the solubility of dermal collagen.