Systems Biology in Reproductive Medicine

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 μM 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 ± 10⁶ 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.