High-pressure liquid chromatographic identification of drugs used in management of arthritis

A screening procedure was developed for the identification of drugs used in the clinical treatment of arthritis. Each glucocorticoid, nonsteroidal anti-inflammatory agent, or tranquilizer was characterized by its retention on a reversed-phase high-pressure liquid chromatographic column and by the ratio of the response of dual UV detectors (254 and 280 nm). Although the retention times of all 14 drugs examined were less than 4 min. each drug could be distinguished easily from the other drugs in the series.     

Minoxidil reduces pulmonary vascular resistance in dogs and cattle

Minoxidil has a direct dilator effect on the systemic arterial smooth muscle. It is potentially an important drug in the treatment of systemic hypertension, especially when combined with beta blockade, which is used to control the associated tachycardia and increase in cardiac output. However, recent observations have suggested that minoxidil might cause pulmonary hypertension. Consequently, we examined the acute effect of monoxidil and propranolol, separately and in combination, on the pulmonary vasculature of the anesthetized dog and the awake calf during normoxia and hypoxia. In both species minoxidil reduced pulmonary vascular resistance. In the dogs this appeared to be the result of a direct action on the pulmonary vascular smooth muscle and in the cattle it was secondary to beta-receptor stimulation. Propranolol alone in the cattle increased the pulmonary pressor response to hypoxia. While we have not examined the possibility that chronic administration of minoxidil might cause pulmonary hypertension by some other mechanism, our acute studies suggest that it reduces, rather than increases, pulmonary vascular resistance. Furthermore, there seems to be a species difference in the mode of its action in dogs and cattle.