Comparison of dopamine contents in lung vasculature of several species

Catecholamine contents of human, rabbit and rat pulmonary vasculature were surveyed. Human pulmonary vasculature was obtained from lobectomized specimens of lung tumors. Catecholamines were measured by high performance liquid chromatography after aluminum extraction. High dopamine (DA) content (1.4 nmol/g wet weight) and high DA/noradrenaline (NA) ratio (17.9%) were observed in rabbit pulmonary arterial trunks. In rabbit pulmonary arterial branches, DA content was 0.26 nmol/g wet weight and DA/NA ratio was 4.2%. In rat, NA contents were less in intra- and extra-pulmonary arteries (1.5 and 4.0 nmol/g wet weight, respectively) compared with pulmonary vasculature of rabbit or with the other vasculatures of the same animals. DA contents were 1.9 and 1.8 nmol/g wet weight in intra- and extra-pulmonary arteries, respectively, and DA/NA ratios were markedly high (218 and 48%, respectively). On the other hand, DA/NA ratios were around 1% in human intrapulmonary arteries and that for large-sized (more than 2 mm in diameter) intrapulmonary vein was 8.5%. Species difference and regional difference among pulmonary vascular beds are evident and at least in human pulmonary artery, DA/NA ratio is not as high as rabbit and rat pulmonary arteries.