Effects of leptin and leptin peptide amide on the release of luteinizing hormone, growth hormone and prolactin from cultured porcine anterior pituitary cells
2006
Nonaka, S.(Iwate Univ., Morioka (Japan). Faculty of Agriculture) | Hashizume, T. | Yamashita, T.
The present study was carried out to determine whether leptin or leptin(116-130) peptide amide (lep (116-130)), an active fragment of the native protein in rats, is able to stimulate the release of luteinizing hormone (LH), growth hormone (GH) or prolactin (PRL) from cultured porcine anterior pituitary (AP) cells in vitro. The AP cells were obtained from 6 month-old pigs and were incubated for 3 h with 10E-11-10E-7 mol/L leptin or lep (116-130) after being cultured in Dulbecco's modified Eagle's medium for 3-4 days. Leptin significantly increased the concentration of LH and GH in the culture medium at concentrations of 10E-8 and 10E-7 mol/L, respectively, compared with the controls (P0.05). Leptin did not increase the concentration of PRL in the culture medium. In contrast to these results, no effects of lep (116-130) on the release of LH, GH or PRL were seen in the cultured cells. These results suggest that leptin stimulates the release of LH and GH by acting directly on porcine AP cells, and that a fragment of leptin protein comprising amino acids 116-130 is not associated with the secretion of hormones in pigs.
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