Thus, in addition to differences in the pattern and duration of the treatments applied, it should be noted that static incubations were carried out using cells cultured in monolayer whereas superfusion studies were carried out on pituitary fragments, in which cell-to-cell communication could conceal the synergistic interaction. buy ortho tri-cyclen online
In summary, we have shown for the first time that SP stimulates LH release by porcine gonadotrophs in both static and dynamic culture systems and that this action is exerted through a GnRH receptor-independent mechanism. Moreover, we demonstrated that SP potentiates GnRH-stimulated LH release in monolayer cultures of pituitary cells. Taken together, our findings suggest that porcine gonadotrophs are a direct target for the peptide, and point to SP as a good candidate for modulating LH secretion from the pig pituitary. Future in vivo studies will be necessary to ascertain whether SP plays a physiological role in the regulation of the hypothalamic-pituitary-gonadal axis in pigs. Likewise, analysis of intracellular signaling mechanisms mediating SP actions described herein will enhance our understanding of porcine gonadotroph function.