expression of leptin and longform leptinreceptor proteins in porcine hypothalamus during oestrous cycle and pregnancy in this study we examined the levels of leptin and obrb protein expression in the discrete areas of the porcine hypothalamus mediobasal hypothalamusmbh preoptic areapoa stalk median eminencesme during mid and lateluteal phases of the oestrous cycle days 1012 and 1416 as well as two stages of pregnancy days 1416 and 3032 the analysis showed that during the cycle leptin protein expression in mbh was higher in the midluteal phase than lateluteal phase in the case of obrb protein expression a higher level was observed in mbh during the lateluteal phase in comparison to the midluteal phase whereas in poa and sme the opposite dependence was noticed in turn during pregnancy leptin protein expression in mbh and poa and obrb protein expression in poa were more pronounced on days 1416 than on days 3032 in contrast leptin protein content in sme as well as obrb protein in mbh and sme was higher on days 3032 than during the earlier stage of pregnancy comparison of leptin and obrb protein expression between the cycle days 1012 and pregnancy showed a higher level of leptin and obrb protein contents in poa as well as in sme during pregnancy on days 1416 and 3032 respectively yet obrb protein expression in poa on days 3032 of pregnancy was lower in comparison to days 1012 of the cycle furthermore during pregnancy leptin protein expression in mbh was lower days 1416 and 3032 whereas obrb protein expression in that area of hypothalamus was higher days 3032 in comparison to the midluteal phase our results indicate that both leptin and obrb are synthesized in the porcine hypothalamus and suggest the participation of leptin in autoparacrine regulation of these brain areas functions including control of reproduction during the oestrous cycle and early pregnancy