Renin secretion from malignant pulmonary metastatic tumour cells of vascular origin

1. A pulmonary chemodectoma/glomangiosarcoma that had metastasized from the thigh was studied after removal from a 22 year old Algerian patient with hypertension, high plasma prorenin and signs of secondary aldosteronism. 2. Renin and renin mRNA were localized in sections of the tumour tissue using monoclonal anti-human renin antibody and human renin cDNA probe, respectively. 3. The cells grew prolifically in culture, but, even though their renin content was similar to that of transfected human juxtaglomerular cell tumour cells (approximately 1 pg/microgram DNA), their rate of secretion of renin was much lower (0.05-0.15 cf. 0.5-1.5 pg/h per microgram DNA). 4. Forskolin (10 mumol/l for 24 h) increased secretion of renin from 1.9 +/- 0.36 to 4.1 +/- 0.64 pg/ml per h of culture (P less than 0.001, n = 11), consistent with cAMP being a second messenger in the secretory mechanism. 5. The cells should provide valuable information about intracellular mechanisms for the regulation of renin synthesis and secretion.