15-keto-13-14-dihydroprostaglandin-f2alpha and Lung-Diseases

We investigated transpulmonary enzymatic conversion of prostaglandin F2 alpha (PGF) to the 13,14-dihydro-15-keto metabolite (PGFM) in normal and acutely lung injured sheep. PGF was infused directly into the right ventricle. Sequential, simultaneous blood samples were drawn from the pulmonary artery (PA) and aorta (A). PGF and PGFM plasma concentrations were quantitated by double antibody radioimmunoassay (RIA). The pulmonary conversion rate of PGF in normal lung was established over a wide range of concentrations in intubated, normoxic, and hemodynamically stable sheep. Both zero and first order kinetics were present. PGF had no physiological effects on either pulmonary or systemic hemodynamics at any infusion rate studied. Acute lung injury was produced by intravenous injections of oleic acid into the PA until the resting mean pulmonary artery pressure doubled. Infusions were then repeated and fractional metabolism of PGF across the lung was assessed. PGF, at infusion rates of 2 micrograms/kg/min and 8 micrograms/kg/min, was metabolized greater than 70% respectively. Thus, there was no difference between control or experimental groups in PGF conversion. We conclude that the in vivo sheep lung has an extensive substrate-dependent capacity to metabolize PGF and this mechanism is resistant to severe acute oleic acid lung injury.

Topics: Animals; Dinoprost; Female; Kinetics; Lung; Lung Diseases; Male; Oleic Acids; Radioimmunoassay; Sheep

Plasma concentrations of 13,14,dihydro-15-keto prostaglandin F2 alpha were measured (1) serially in six healthy young adults over 24-25 h; (2) in 62 male and 61 female subjects aged 3 to 64 years; (3) before and after a 12-h volley ball marathon in eight players and eight controls, and (4) in 41 geriatric in-patients aged 65 years and over. There was a small diurnal variation in plasma PGF2 alpha M concentration, levels being highest around 08.00 to 09.00 h. Concentrations did not change with age in fit subjects up to 64 years. Significantly increased concentrations were found in elderly sick patients, high levels in men being associated most often with pulmonary symptoms. Concentrations were not increased significantly by 12 h of competitive sport.

Topics: Adolescent; Adult; Aged; Aging; Child; Child, Preschool; Circadian Rhythm; Dinoprost; Female; Humans; Lung Diseases; Male; Middle Aged; Physical Exertion; Prostaglandins F