Antepartal insulin-like growth factor concentrations indicating differences in the metabolic adaptive capacity of dairy cows

作者：Piechotta Marion^*; Holzhausen Lars; Araujo Marcelo Gil; Heppelmann Maike; Sipka Anja; Pfarrer Chistiane; Schuberth Hans Joachim; Bollwein Heinrich

来源：Journal of Veterinary Science, 2014, 15(3): 343-352.

DOI：10.4142/jvs.2014.15.3.343

• cattle
• growth hormone
• insulin-like growth factor I
• metabolism
• suppressor of cytokine signaling

Cows with different Insulin-like Growth Factor-I (IGF-I) concentrations showed comparable expression levels of hepatic growth hormone receptor (GHR). Suppressor of cytokine signaling 2 (SOCS2), could be responsible for additional inhibition of the GHR signal cascade. The aims were to monitor cows with high or low antepartal IGF-I concentrations (IGF-I-high or IGF-I-low), evaluate the interrelationships of endocrine endpoints, and measure hepatic SOCS2 expression. Dairy cows (n = 20) were selected (240 to 254 days after artificial insemination (AI)). Blood samples were drawn daily (day -17 until calving) and IGF-I, GH, insulin, thyroid hormones, estradiol, and progesterone concentrations were measured. Liver biopsies were taken (day 264 +/- 1 after AI and postpartum) to measure mRNA expression (IGF-I, IGFBP-2, IGFBP-3, IGFBP-4, acid labile subunit (ALS), SOCS2, deiodinasel, GHR1A). IGF-I concentrations in the two groups were different p < 0.0001). However, GH concentrations and GHR1A mRNA expression were comparable (p > 0.05). Thyroxine levels and ALS expression were higher in the IGF-I-high cows compared to IGF-I-low cows. Estradiol concentration tended to be greater in the IGF-I-low group (p = 0.06). It was hypothesized that low IGF-I levels are associated with enhanced SOCS2 expression although this could not be decisively confirmed by the present study.

• 出版日期2014-9