Formation of nitrogen-containing metabolites from the main iridoids of Harpagophytum procumbens and H. zeyheri by human intestinal bacteria.

The study of the metabolism of iridoid glycosides from Harpagophytum procumbens and Harpagophytum zeyheri by human intestinal bacteria, was realized in order to elucidate compounds responsible for the pharmacological activities of Harpagophytum. Harpagide, harpagoside and 8-O-p-coumaroyl-harpagide were transformed into the pyridine monoterpene alkaloid aucubinine B by human fecal flora and by bacteria isolated from this flora. Aucubinine B was also prepared from harpagide, harpagoside and 8-O-p-coumaroylharpagide, by beta-glucosidase in the presence of NH4+.

[Nifedipine in the treatment of chronic cor pulmonale]. / Apport de la nifédipine dans le traitement du coeur pulmonaire chronique.

The effects of a single dose of nifedipine (20 mg sublingual) on the haemodynamics and parameters of tissue oxygenation were assessed by right heart catheterisation and oximetry of mixed arterial and venous blood in 24 patients with pulmonary hypertension secondary to severe chronic obstructive airways disease. The haemodynamic effects of 15 days' oral therapy (30 mg/day) were studied in 10 other patients. Significant improvement in right ventricular pump function (25 p. 100 increase in cardiac index. average reduction of 3 mmHg of right ventricular end diastolic pressure), and lowering of pulmonary hypertension (mean pulmonary artery pressures reduced by an average of 10 p. 100 and total pulmonary resistance by 25 p. 100) were observed after the single dose of nifedipine. This improvement was maintained after oral therapy for 15 days. The significant improvement of tissue oxygenation was reflected by an increase in oxygen transport (+ 24 p. 100), in the coefficient of delivered oxygen (+ 19 p. 100), in the oxygen partial pressure (+ 4 p. 100) and saturation (+ 3 p. 100) in the mixed venous blood. Arterial lactate concentrations fell by about 28 p. 100. In addition, a moderate fall in ppO2 and arterial saturation was observed due to a weak shunt effect which was more than compensated by the increase in cardiac output, and especially by the increase in the coefficient of relieved oxygen. These results show that nifedipine may be a valuable addition in the treatment of cor pulmonale secondary to chronic obstructive airways disease by improving right ventricular haemodynamics and pulmonary circulation and by increasing the quantity of oxygen delivered.