Gene expression and peptide localization for LH/hCG receptor in porcine small and large luteal cells: Possible regulation by opioid peptides

The aim of the present studies was to investigate (1) the presence of LH re ceptor (LHR) in porcine separated small (SLCs) and large (LLCs) luteal cell s taken from mid-luteal corpora lutea and (2) the influence of opioid agoni st, FK 33-824 (FK) on LHR gene expression in these cells. Immunocytochemist ry revealed intense staining for LHR in both SLCs and LLCs. Reverse transcr iption-polymerase chain reaction (RT-PCR) and Southern hybridization were u sed to check the effect of FK and hCG on LHR gene expression. The LHR gene expression was observed in non-stimulated LLCs and in both types of cells a fter treatment with FK or hCG. FK stimulated LHR gene expression in,SLCs an d inhibited the gene expression in LLCs. Moreover, FK inhibited and potenti ated stimulatory influence of hCG on the gene expression in LLCs and SLCs, respectively. These results suggest that LHR gene expression in porcine lut eal cells can be regulated by opioid peptides.