Jonsson N N, Daniel R C
Department of Farm Animal Medicine and Production, University of Queensland, St Lucia, Australia.
Zentralbl Veterinarmed A. 1997 Jul;44(5):281-7. doi: 10.1111/j.1439-0442.1997.tb01112.x.
The objectives of the study were to use sheep as a model to determine whether a reduction in plasma calcium concentration similar to that observed during periods of postpartum subclinical hypocalcaemia in lactating dairy cattle might affect the blood flow to the ovaries. Different levels of hypocalcaemia were induced in each of six, non-pregnant sheep by the slow intravenous infusion of Na2-EDTA. Measurements of blood flow to the ovaries were made before and after the induction of hypocalcaemia, using 113Sn and 46Sc radiolabelled microspheres. As plasma ionized calcium was reduced, there was a significant decline in ovarian blood flow. Ovarian blood flow (percentage of resting) = 0.54 Ca++ (percentage of resting) + 58.4. This model was significant at P < 0.01, with R2 = 0.92. Accordingly, a reduction in plasma ionized calcium of 50% would yield a reduction in ovarian blood flow of 16%.
本研究的目的是利用绵羊作为模型，以确定类似于泌乳奶牛产后亚临床低钙血症期间所观察到的血浆钙浓度降低是否会影响卵巢的血流量。通过缓慢静脉输注Na2-EDTA，在6只未怀孕的绵羊中分别诱导出不同程度的低钙血症。在诱导低钙血症前后，使用113Sn和46Sc放射性标记微球测量卵巢的血流量。随着血浆离子钙的降低，卵巢血流量显著下降。卵巢血流量（静息百分比）= 0.54 Ca++（静息百分比）+ 58.4。该模型在P < 0.01时具有显著性，R2 = 0.92。因此，血浆离子钙降低50%会使卵巢血流量降低16%。
