Receptor-binding changes in copper-deficient rats

Male weanling Sprague-Dawley rats were fed a copper-deficient diet for 40 days. Copper-deficient rats weighed significantly (p less than 0.001) less (175 +/- 7 g) than copper-supplemented rats (230 +/- 6 g). Hematocrits were also significantly (p less than 0.001) decreased in deficient as compared to control animals from 43 +/- 0.6 to 30 +/- 2.7%. The binding of 3H-QNB to striatal and cerebellar membrane muscarinic receptors from control and deficient rats increased from 594 +/- 25 to 704 +/- 31 (p less than 0.02) and from 19 +/- 2 to 28 +/- 3 (p less than 0.01) pmol/g protein, respectively. Similarly, 3H-muscimol binding to GABA receptors (cerebellum) also increased from 39 +/- 5 to 58 +/- 3 (p less than 0.02) pmol/g protein. 3H-diazepam binding to benzodiazepine receptors in deficient versus control animal frontal cortex membranes decreased from 92 +/- 8 to 75 +/- 5 (p less than 0.02) pmol/g protein, respectively. These results may help explain CNS manifestations of copper deficiency.