TY - JOUR
T1 - Effect of recombinant bovine tumor necrosis factor-α on hormone release in lactating cows
AU - Kushibiki, Shiro
AU - Shingu, Hiroyuki
AU - Komatsu, Tokushi
AU - Itoh, Fumiaki
AU - Kasuya, Etsuko
AU - Aso, Hisashi
AU - Hodate, Koichi
PY - 2006/12/1
Y1 - 2006/12/1
N2 - Tumor necrosis factor (TNF)-α is a powerful macrophage cytokine released during infection, circulating in the blood to produce diverse effects in the organism. We examined the effect of recombinant bovine TNF-α (rbTNF-α) administration on hormone release in dairy cows during early lactation. Twelve non-pregnant Holstein cows were treated subcutaneously with rbTNF-a (2.5 μg/kg) or saline twice (at 11.00 and 23.00 hours). At 11.00 hours the next day, the cows were given growth hormone-releasing hormone (GHRH, 0.25p.g/kg), thyrotrophin-releasing hormone (TRH, 1.0 μg/kg), thyroid-stimulating hormone (TSH, 10 μg/kg) or adrenocorticotropic hormone (500 μg/head) via the jugular vein. In the growth hormone-releasing hormone challenge, the plasma growth hormone concentration was lower in the rbTNF-a group than in the control (saline) group. The growth hormone and TSH responses to TRH were also smaller in the rbTNF-α group than in the control. The plasma prolactin response to TRH was not affected by the rbTNF-α treatment. In the TSH challenge, the rbTNF-α-treated cows had lower responses, as measured by plasma triiodothyronine and thyroxine, than the control cows. The rbTNF-α treatment produced an increase in the basal plasma cortisol level, but the cortisol response to adrenocorticotropic hormone was the same level in both groups. The plasma concentrations of TNF-α and interleukin-1βin the cows were elevated by the rbTNF-α treatment. The milk yield was reduced by the rbTNF-α administration during 4 days. These data demonstrate that TNF-α alters the secretion of pituitary and thyroid hormones in lactating cows. This effect may contribute to the suppression of the lactogenic function of the mammary gland observed in cases of coliform mastitis with high circulating TNF-α levels.
AB - Tumor necrosis factor (TNF)-α is a powerful macrophage cytokine released during infection, circulating in the blood to produce diverse effects in the organism. We examined the effect of recombinant bovine TNF-α (rbTNF-α) administration on hormone release in dairy cows during early lactation. Twelve non-pregnant Holstein cows were treated subcutaneously with rbTNF-a (2.5 μg/kg) or saline twice (at 11.00 and 23.00 hours). At 11.00 hours the next day, the cows were given growth hormone-releasing hormone (GHRH, 0.25p.g/kg), thyrotrophin-releasing hormone (TRH, 1.0 μg/kg), thyroid-stimulating hormone (TSH, 10 μg/kg) or adrenocorticotropic hormone (500 μg/head) via the jugular vein. In the growth hormone-releasing hormone challenge, the plasma growth hormone concentration was lower in the rbTNF-a group than in the control (saline) group. The growth hormone and TSH responses to TRH were also smaller in the rbTNF-α group than in the control. The plasma prolactin response to TRH was not affected by the rbTNF-α treatment. In the TSH challenge, the rbTNF-α-treated cows had lower responses, as measured by plasma triiodothyronine and thyroxine, than the control cows. The rbTNF-α treatment produced an increase in the basal plasma cortisol level, but the cortisol response to adrenocorticotropic hormone was the same level in both groups. The plasma concentrations of TNF-α and interleukin-1βin the cows were elevated by the rbTNF-α treatment. The milk yield was reduced by the rbTNF-α administration during 4 days. These data demonstrate that TNF-α alters the secretion of pituitary and thyroid hormones in lactating cows. This effect may contribute to the suppression of the lactogenic function of the mammary gland observed in cases of coliform mastitis with high circulating TNF-α levels.
KW - Hormone
KW - Lactating cow
KW - Mastitis
KW - Tumor necrosis factor-α
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U2 - 10.1111/j.1740-0929.2006.00392.x
DO - 10.1111/j.1740-0929.2006.00392.x
M3 - Article
AN - SCOPUS:33845332082
VL - 77
SP - 603
EP - 612
JO - Animal Science Journal
JF - Animal Science Journal
SN - 1344-3941
IS - 6
ER -