HPLC determination of an oxytocin-like peptide produced by isolated guinea pig Leydig cells: stimulation by ascorbate.
Highly purified populations of guinea pig Leydig cells were incubated with a maximally stimulating dose of 100 ng/mL LH for 24 h in the presence of increasing concentrations of sodium ascorbate. Sample supernatants were extracted, concentrated under vacuum, and reconstituted with acidified absolute ethanol. Samples were analyzed for oxytocin using high-performance liquid chromatography with electrochemical detection and known concentrations of an authentic oxytocin standard. Leydig cells stimulated with 0, 25, and 50 microM ascorbate produced and secreted 40.1 +/- 1.23, 77.4 +/- 13.8, 74.2 +/- 26.3 pg of an oxytocin-like peptide, respectively, per 1 x 10(6) cells. These results indicate that guinea pig Leydig cells are capable of producing an oxytocin-like peptide de novo and that low concentrations of ascorbate stimulate the production of this peptide in Leydig cells cultured in vitro.
Kukucka
M A
MA
Department of Biomedical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg 24061.
Misra
H P
HP
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D006168:Guinea Pigs; D007985:Leydig Cells / Q000187:drug effects* / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000494:pharmacology; D008297:Male; D010121:Oxytocin / Q000032:analysis / Q000096:biosynthesis*
D010121:Oxytocin; D007986:Luteinizing Hormone; D001205:Ascorbic Acid