Effects of Ghrelin on Growth Hormone Secretion from Cultured Adenohypophysial Cells in Cattle
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Accession number;03A0491626
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| Title;Effects of Ghrelin on Growth Hormone Secretion from Cultured Adenohypophysial Cells in Cattle |
| Author;
HASHIZUME T
(Iwate Univ., Morioka, Jpn)
HORIUCHI M
(Iwate Univ., Morioka, Jpn)
TATE N
(Iwate Univ., Morioka, Jpn)
NONAKA S
(Iwate Univ., Morioka, Jpn)
KOJIMA M
(Kurume Univ., Kurume, Jpn)
HOSODA H
(National Cardiovascular Center Res. Inst., Osaka, Jpn)
KANGAWA K
(National Cardiovascular Center Res. Inst., Osaka, Jpn)
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Journal Title;Endocr J
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Journal Code:F0625A
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ISSN:0918-8959
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VOL.50;NO.3;PAGE.289-295(2003)
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| Figure&Table&Reference;FIG.3, REF.26 |
| Pub. Country;Japan |
| Language;English |
| Abstract;To clarify the direct effects of ghrelin on growth hormone (GH) release from anterior pituitary (AP) cells in cattle, GH-releasing effects of human ghrelin (hGhrelin) and rat ghrelin (rGhrelin) on bovine AP cells were compared with those of GH-releasing hormone (GHRH) in vitro. The AP cells were obtained from Holstein steers and were incubated for 2h with the peptides after incubating in DMEM for 3 days. hGhrelin and rGhrelin significantly stimulated GH release from the cultured cells at doses from 10-10 to 10-7M and from 10-9 to 10-7M, respectively (P<0.05). The rates of increase in GH at 10-10, 10-9, 10-8 and 10-7M hGhrelin were 26, 26, 59 and 100% compared with controls, respectively, and those of increase in GH at 10-9, 10-8 and 10-7M rGhrelin were 58, 74 and 106%, respectively. GHRH significantly increased GH concentrations in cultured media at a dose as low as 10-13M compared with the control (P<0.05). When hGhrelin (10-8M) and GHRH (10-8M) were added together, the release of GH induced by both peptides was significantly greater than that by hGhrelin alone (P<0.05), and tended to be greater than that by GHRH alone. Somatostatin (SS,10-7M) significantly blunted GH release induced by hGhrelin (10-8M) and GHRH (10-8M) (P<0.05). In the presence of SS, the percent increase in GH released with hGhrelin plus GHRH was 42% and 14% greater than that by either hGhrelin or GHRH alone, respectively (P<0.05). These results show that ghrelin directly stimulates the release of GH from anterior pituitary cells, and that SS modifies ghrelin-stimulated GH release in cattle. (author abst.) |
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