Hustmyer F G, Beitz D C, Goff J P, Nonnecke B J, Horst R L, Reinhardt T A
Department of Animal Science, Iowa State University, Ames 50011.
J Dairy Sci. 1994 Nov;77(11):3324-30. doi: 10.3168/jds.S0022-0302(94)77273-8.
Continuous infusion of 1,25-dihydroxyvitamin D3 in the bovine elevated 1,25-dihydroxyvitamin D3 in plasma. Plasma 1,25-dihydroxyvitamin D3 remained elevated until infusions were discontinued. Increased 1,25-dihydroxyvitamin D3 was associated with hypercalcemia (11 to 12 mg/dl) that continued for several days postinfusion. Elevated 1,25-dihydroxyvitamin D3 also was associated with a significant 70% enhancement of lymphocyte proliferation in cells treated with concanavalin A. Cessation of infusion of 1,25-dihydroxyvitamin D3 resulted in the return of 1,25-dihydroxyvitamin D3 in plasma and lymphocyte proliferative response to preinfusion amounts. Proliferation in response to pokeweed mitogen was significantly inhibited on d 3 of infusions of 1,25-dihydroxyvitamin D3. Administration of parathyroid hormone for 4 d resulted in a sustained hypercalcemia (approximately 13 mg/dl) and a transient 1-d increase in 1,25-dihydroxyvitamin D3 in plasma. Parathyroid hormone treatment generally did not affect the response of bovine lymphocytes to mitogen. In vivo elevation of 1,25-dihydroxyvitamin D3 is either moderately immunostimulating or exerts no effect on mitogen-stimulated proliferation of lymphocytes. These results contrast with the in vitro results suggesting that 1,25-dihydroxyvitamin D3 is only immunosuppressive.
在牛体内持续输注1,25 - 二羟基维生素D3可使血浆中1,25 - 二羟基维生素D3水平升高。血浆1,25 - 二羟基维生素D3在输注停止前一直保持升高。1,25 - 二羟基维生素D3升高与高钙血症（11至12mg/dl）相关，高钙血症在输注后持续数天。1,25 - 二羟基维生素D3升高还与用伴刀豆球蛋白A处理的细胞中淋巴细胞增殖显著增强70%相关。停止输注1,25 - 二羟基维生素D3导致血浆中1,25 - 二羟基维生素D3和淋巴细胞增殖反应恢复到输注前水平。在输注1,25 - 二羟基维生素D3的第3天，对商陆有丝分裂原的增殖反应受到显著抑制。给予甲状旁腺激素4天导致持续的高钙血症（约13mg/dl）和血浆中1,25 - 二羟基维生素D3短暂升高1天。甲状旁腺激素治疗一般不影响牛淋巴细胞对有丝分裂原的反应。体内1,25 - 二羟基维生素D3升高要么具有中等免疫刺激作用，要么对有丝分裂原刺激的淋巴细胞增殖无影响。这些结果与体外结果形成对比，体外结果表明1,25 - 二羟基维生素D3仅具有免疫抑制作用。
