Hanigan M D, Calvert C C, DePeters E J, Reis B L, Baldwin R L
Department of Animal Science, University of California, Davis 95616.
J Dairy Sci. 1992 Jan;75(1):161-73. doi: 10.3168/jds.S0022-0302(92)77750-9.
Studies of mammary arteriovenous difference were conducted on multiparous lactating Holstein cows (n = 21) on d 35, 70, 105, and 126 of lactation to examine kinetic relationships between arterial concentration and mammary gland extraction of AA. Additionally, these cows were paired by previous lactational performance and assigned to bST-treated or control groups to examine the effect of bST treatment on AA concentration and extraction by lactating mammary glands. Treated cows were injected daily with 40 mg of recombinant bST from d 71 through 126 of lactation. Arterial concentrations of Asp, Ser, Asn, Gly, beta-aminoisobutyrate, and Met were increased. Concentrations of Val, Ile, Leu, Phe, Orn, and Lys were decreased in bST-treated cows compared with controls. Increased extractions of Asp and Met by mammary glands in treated versus control cows were correlated positively with treatment-induced changes in arterial concentrations of these AA. However, increased mammary extractions of Arg, cystathionine, Leu, and Lys by bST-treated compared with control cows were not correlated with bST-induced changes in arterial concentrations of these AA. Extractions of Asn, His, Thr, Arg, Tyr, Met, cystathionine, cystine, Ile, Phe, Orn, Glu, Gly, Tau, Cit, Leu, and Val were correlated linearly with arterial concentrations (r2 greater than .15) of each AA. Extractions of Asp, Glu, Ser, Asn, Gly, Gln, Tau, His, Cit, Thr, Pro, Tyr, Val, cystine, Ile, Leu, Trp, Orn, and Lys also were correlated with arteriovenous differences of Met.
在泌乳第35、70、105和126天，对经产泌乳荷斯坦奶牛（n = 21）进行乳腺动静脉差异研究，以检查氨基酸（AA）动脉浓度与乳腺摄取之间的动力学关系。此外，根据先前的泌乳性能将这些奶牛配对，并分为bST处理组或对照组，以检查bST处理对泌乳乳腺中AA浓度和摄取的影响。从泌乳第71天至126天，给处理组奶牛每天注射40 mg重组bST。天冬氨酸、丝氨酸、天冬酰胺、甘氨酸、β-氨基异丁酸和蛋氨酸的动脉浓度升高。与对照组相比，bST处理奶牛的缬氨酸、异亮氨酸、亮氨酸、苯丙氨酸、鸟氨酸和赖氨酸浓度降低。与对照组相比，处理组奶牛乳腺中天冬氨酸和蛋氨酸摄取增加与这些AA动脉浓度的处理诱导变化呈正相关。然而，与对照组相比，bST处理奶牛乳腺中精氨酸、胱硫醚、亮氨酸和赖氨酸摄取增加与这些AA动脉浓度的bST诱导变化无关。天冬酰胺、组氨酸、苏氨酸、精氨酸、酪氨酸、蛋氨酸、胱硫醚、胱氨酸、异亮氨酸、苯丙氨酸、鸟氨酸、谷氨酸、甘氨酸、牛磺酸、瓜氨酸、亮氨酸和缬氨酸的摄取与每种AA的动脉浓度呈线性相关（r2大于0.15）。天冬氨酸、谷氨酸、丝氨酸、天冬酰胺、甘氨酸、谷氨酰胺、牛磺酸、组氨酸、瓜氨酸、苏氨酸、脯氨酸、酪氨酸、缬氨酸、胱氨酸、异亮氨酸、亮氨酸、色氨酸、鸟氨酸和赖氨酸的摄取也与蛋氨酸的动静脉差异相关。
