Hplc Determination Of An Oxytocin-like Peptide Produced By Isolated Guinea Pig Leydig Cells: Stimulation By Ascorbate

HPLC determination of an oxytocin-like peptide produced by isolated guinea pig Leydig cells: stimulation by ascorbate by Mark A. Kukucka and Hara P. Misra Department of Biomedical Sciences Virginia-Maryland Regional College of Veterinary Medicine Virginia Polytechnic Institute & State University, Blacksburg, VA 24061 ABSTRACT 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. CITATION Kukucka, Mark A. and Hara P. Misra. 1992. HPLC determination of an oxytocin-like peptide produced by isolated guinea pig Leydig cells: stimulation by ascorbate. Arch Androl 29(2):185-90.