Expression of leptin and long-form leptin-receptor proteins in porcine hypothalamus during oestrous cycle and pregnancy.
In this study, we examined the levels of leptin and OB-Rb protein expression in the discrete areas of the porcine hypothalamus (mediobasal hypothalamus--MBH, pre-optic area--POA, stalk median eminence--SME) during mid- and late-luteal phases of the oestrous cycle (days 10-12 and 14-16) as well as two stages of pregnancy (days 14-16 and 30-32). The analysis showed that during the cycle, leptin protein expression in MBH was higher in the mid-luteal phase than late-luteal phase. In the case of OB-Rb protein expression, a higher level was observed in MBH during the late-luteal phase in comparison to the mid-luteal phase, whereas in POA and SME the opposite dependence was noticed. In turn, during pregnancy, leptin protein expression in MBH and POA, and OB-Rb protein expression in POA were more pronounced on days 14-16 than on days 30-32. In contrast, leptin protein content in SME as well as OB-Rb protein in MBH and SME was higher on days 30-32 than during the earlier stage of pregnancy. Comparison of leptin and OB-Rb protein expression between the cycle (days 10-12) and pregnancy showed a higher level of leptin and OB-Rb protein contents in POA as well as in SME during pregnancy (on days 14-16 and 30-32, respectively). Yet, OB-Rb protein expression in POA on days 30-32 of pregnancy was lower in comparison to days 10-12 of the cycle. Furthermore, during pregnancy, leptin protein expression in MBH was lower (days 14-16 and 30-32), whereas OB-Rb protein expression in that area of hypothalamus was higher (days 30-32) in comparison to the mid-luteal phase. Our results indicate that both leptin and OB-Rb are synthesized in the porcine hypothalamus and suggest the participation of leptin in auto/paracrine regulation of these brain areas functions, including control of reproduction during the oestrous cycle and early pregnancy.
Siawrys
G
G
Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, Olsztyn 10-719, Poland. gabri@uwm.edu.pl
Kaminski
T
T
Smolinska
N
N
Przala
J
J
D000818:Animals; D030762:Estrous Cycle / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D007031:Hypothalamus / Q000378:metabolism*; D020738:Leptin / Q000378:metabolism*; D011247:Pregnancy; D011270:Pregnancy, Animal; D054411:Receptors, Leptin / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D013552:Swine / Q000502:physiology*
D020738:Leptin; D054411:Receptors, Leptin