Sulfation of minoxidil by human platelet sulfotransferase

• Published in: Clinica chimica acta Vol. 169; no. 2; pp. 217 - 227
• Main Authors: Johnson, Garland A., Baker, Carolyn A.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 16.11.1987; Elsevier
• Subjects: Adolescent; Adult; Antihypertensive agents; Arylsulfotransferase; Biological and medical sciences; Blood Platelets - enzymology; Cardiovascular system; Chromatography, High Pressure Liquid; Humans; Hydrogen-Ion Concentration; In Vitro Techniques; Male; Medical sciences; Middle Aged; Minoxidil; Minoxidil - metabolism; Minoxidil sulfate; Pharmacology. Drug treatments; Platelet; Platelet Count; Sulfotransferase; Sulfurtransferases - blood; Platelet; Minoxidil sulfate; Minoxidil; Sulfotransferase; Sulfatation
• ISSN: 0009-8981; 1873-3492
• DOI: 10.1016/0009-8981(87)90322-6

In an attempt to determine whether (1) sulfotransferase activity in human platelets would convert minoxidil to minoxidil sulfate and (2) inter-subject variations in this sulfotransferase activity could be noted, platelet homogenates were incubated with minoxidil and 35S-PAPS in HEPES buffer at 37°C for 30 min. Radioactivity which was extracted into ethyl acetate and shown by HPLC to elute with authentic minoxidil sulfate was counted by scintillation counting. Aliquots of the platelet homogenates were also preincubated at 43°C for 15 min to determine the thermal stability of the sulfotransferase activity. Sulfotransferase activity in platelets from 48 adult males ranged from 0.9–13.2 pmol minoxidil sulfate produced/10 7 platelets per 30 min (mean 4.91 ± 2.84 pmol/10 7 platelets per 30 min ± Sd). Thermal stable sulfotransferase activity ranged from 0.2–7.6 pmol minoxidil produced/10 7 platelets per 30 min and varied from 15 to 57% of the total sulfotransferase activity. Thus, the results indicate that human platelets can effect the sulfation of minoxidil and that sulfotransferase activity does show inter-subject variation.