The Influence of Opioid Peptides on Steroidogenesis in Porcine Granulosa Cells

Abstract

The present studies were undertaken to examine the influence of mu (beta-endorphin, DAMGO, FK 33-824), delta (met-enkephalin, leu-enkephalin, DPLPE) and kappa opioid receptor agonists (dynorphin A, dynorphin B, U 50488) used at different doses (1-1000 nM) alone and in combination with LH (100 ng/ml) on steroidogenesis in porcine granulosa cells derived from large follicles. The effects of mu, delta and kappa receptor agonists on both basal and LH-induced progesterone (P4) secretion were negligible. Agonists of mu opioid receptors reduced basal androstenedione (A4), testosterone (T) and oestradiol (E2) release. Co-treatment with LH entirely abolished the inhibitory effect of these agonists on A4 and E2 secretion and resulted in an increase in T release. The addition of delta receptor agonists was followed by a decrease in basal A4, T and E2 secretion. The cells incubated in the presence of LH increased the androgen production and abrogated the inhibitory effect of delta agonists on E2 output. Basal A4, T and E2 release was also suppressed by kappa receptor agonists. The presence of LH in culture media extended the inhibitory effect of these opioids on E2 output and caused either abolition of the inhibitory influence of kappa agonists or even augmentation of both androgen release in response to the opioids. In conclusion, these data support the involvement of three major types of opioid receptors in the regulation of porcine granulosa cell steroidogenesis.

The expression of mRNAs for opioid precursors in endometrium of cyclic and early pregnant pigs; effects of IL-1β, IL-6 and TNFα

“…They affect the reproductive axis in females at all levels. In studies performed in vitro, with the use of porcine tissues/cells, selected opioid agonists appeared to influence gonadotropin releasing hormone release from the stalk median eminence (Okrasa et al, 1995), gonadotropin secretion by pituitary cells (Wylot et al, 2013) and steroid hormones by ovarian cells (Kaminski et al, 2003(Kaminski et al, , 2004. It was also reported that EOPs may affect many different processes in the uterus, including: cell proliferation (Vértes et al, 1996), apoptosis (Chatzaki et al, 2001), immunological interactions and myometrial contractility (Zoumakis et al, 1997) as well as the early pregnancy events (Li et al, 1992(Li et al, , 1993.…”

Expression of adiponectin receptors 1 and 2 in the ovary and concentration of plasma adiponectin during the oestrous cycle of the pig

“…The granulosa cells were aspirated with a syringe and additionally washed out with a strong stream of media directed to the internal wall of the follicle (Kaminski et al, 2004). Granulosa cells were scraped from theca interna layer and theca cells were enzymatically dispersed in 0.25% trypsin solution (Kaminski et al, 2003).…”

The Novel Roles of Neutrophils Via Opioid Peptides: Regulation of the Estrous Cycle and Pain

“…We then examined from which blood vessels neutrophils enter the female genital organs but we failed to obtain definitive results (Sasaki et al unpublished). In the meantime, we came across publications reporting that opioid peptides regulate steroidogenesis in theca cells and granulose cells in the ovaries (Kaminski et al 2003(Kaminski et al , 2004, and we finally hypothesized that neutrophils may secrete opioid peptides in the ovaries, thereby regulating the estrous cycle (Sasaki et al 2011). …”