TY - JOUR
T1 - Suppressing effects of short-chain fatty acids on growth hormone (GH)- releasing hormone-induced GH release in isolated anterior pituitary cells of goats
AU - Katoh, K.
AU - Ohata, Y.
AU - Ishiwata, H.
N1 - Funding Information:
☆ This study was supported by a Grant-in-Aid (09460122) for Scientific Research from The Ministry of Education, Science, Sports and Culture in Japan.
PY - 1999/7
Y1 - 1999/7
N2 - The involvement of tetrodotoxin-sensitive Na+ channels and receptor- operated nonspecific Ca2+ channels, and the effects of short-chain fatty acids, on growth hormone (GH) release induced by GH-releasing hormone (GHRH) were investigated in cultured and freshly isolated caprine anterior pituitary cells. In 3-d cultured cells in Dulbecco's modified Eagle's medium, an increase in GH release induced by GHRH (10 nmol/l) was moderately, but significantly, reduced by a voltage-sensitive Na+ channel antagonist tetrodotoxin (1 μmol/1). The GHRH-induced GH increase, which was not affected by a simultaneous addition of a receptor-operated nonspecific Ca2+ channel antagonist tetramethrine (0.1 mmol/1), was significantly reduced by a voltage-sensitive L-type Ca2+ channel antagonist nifedipine (1 μmol/l). Propionate and butyrate at 10 mmol/l, however, not only suppressed basal GH release but also significantly reduced the GH increase induced by 10 nmol/l of GHRH. The inhibitory action of these acids was also reproduced by an addition of β-hydroxy butyrate (10 mmol/l) and octanoate (10 mmol/l). In freshly isolated and perifused cells, butyrate (10 mmol/l) as well as somatostatin (100 nmol/l) significantly reduced the GH increase induced by GHRH. From these findings we conclude that tetrodotoxin-sensitive Na+ channels and voltage-dependent L-type Ca2+ channels are involved in the cellular mechanism for GHRH-induced GH release, and that short-chain fatty acids such as propionate and butyrate have a direct action on somatotrophs to reduce basal and GHRH-induced GH release, in caprine somatotrophs.
AB - The involvement of tetrodotoxin-sensitive Na+ channels and receptor- operated nonspecific Ca2+ channels, and the effects of short-chain fatty acids, on growth hormone (GH) release induced by GH-releasing hormone (GHRH) were investigated in cultured and freshly isolated caprine anterior pituitary cells. In 3-d cultured cells in Dulbecco's modified Eagle's medium, an increase in GH release induced by GHRH (10 nmol/l) was moderately, but significantly, reduced by a voltage-sensitive Na+ channel antagonist tetrodotoxin (1 μmol/1). The GHRH-induced GH increase, which was not affected by a simultaneous addition of a receptor-operated nonspecific Ca2+ channel antagonist tetramethrine (0.1 mmol/1), was significantly reduced by a voltage-sensitive L-type Ca2+ channel antagonist nifedipine (1 μmol/l). Propionate and butyrate at 10 mmol/l, however, not only suppressed basal GH release but also significantly reduced the GH increase induced by 10 nmol/l of GHRH. The inhibitory action of these acids was also reproduced by an addition of β-hydroxy butyrate (10 mmol/l) and octanoate (10 mmol/l). In freshly isolated and perifused cells, butyrate (10 mmol/l) as well as somatostatin (100 nmol/l) significantly reduced the GH increase induced by GHRH. From these findings we conclude that tetrodotoxin-sensitive Na+ channels and voltage-dependent L-type Ca2+ channels are involved in the cellular mechanism for GHRH-induced GH release, and that short-chain fatty acids such as propionate and butyrate have a direct action on somatotrophs to reduce basal and GHRH-induced GH release, in caprine somatotrophs.
KW - Anterior pituitary cells
KW - GH release
KW - Goat
KW - Short-chain fatty acids
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U2 - 10.1016/S0739-7240(99)00019-3
DO - 10.1016/S0739-7240(99)00019-3
M3 - Article
C2 - 10484133
AN - SCOPUS:0033167376
VL - 17
SP - 85
EP - 93
JO - Domestic Animal Endocrinology
JF - Domestic Animal Endocrinology
SN - 0739-7240
IS - 1
ER -