CATECHOLAMINE CONTENT OF SPINAL CORD

Values for the catecholamine content of spinal cords of rats, rabbits, cats, humans, hogs, and oxen were obtained. The catecholamine content tended to decrease with increasing size of the species. Dopamine averaged 1.0 micrograms/g of wet tissue in the rat, and 0.2 micrograms/g in the ox; noradrenaline averaged 0.15 micrograms/g in the rat, and 0.10 micrograms/g in the ox. Adrenaline could not be detected with certainty. The catecholamine content of gray matter was much greater than that of white and seemed greater in the posterior than in the anterior part of cord. No segmental distribution was apparent. Dopamine and noradrenaline were both found in the free and bound state. Modifications to previous methods of catecholamine determinations are described. Recoveries in the analyses were determined by using radioactive tracers in preference to the usual method of doing parallel analyses. No deterioration in catecholamine content of tissues was apparent for the first 3 hours after death, but thereafter dete...