Torres Diego A, Freitas Mariella B, Gonçalves Reggiani V
Animal Biology Department, Federal University of Viçosa, Av. P.H. Rolfs, 36570-000, Viçosa, MG, Brazil.
Reprod Fertil Dev. 2018 May;30(5):681-688. doi: 10.1071/RD17163.
Large amounts of calcium are required during pregnancy and lactation to support fetal and neonatal bone growth and calcification. An inadequate supply of calcium during these stages can lead to unsuccessful reproduction or impaired offspring fitness. During reproduction, female mammals undergo numerous physiological changes, including adaptations to allow an adequate supply of calcium. The lack of quantitative studies analysing these physiological changes from a comparative perspective limits our ability to explain and understand these adaptations. Herein, we present our meta-analysis of studies reporting changes in bone turnover and calcium homeostasis during pregnancy and lactation in 14 species of mammals. Our meta-analysis of 60 studies showed that all species have a similar pattern of physiological changes during pregnancy and lactation, which include: (1) decreased serum calcium concentrations; (2) bone tissue loss; (3) decreased serum calcitonin and parathyroid hormone concentrations; and (4) increased serum calcitriol concentration, regardless of changes in parathyroid hormone concentrations. In addition, we found a negative relationship between: (1) serum calcium concentrations and the number of teats; and (2) serum parathyroid hormone concentrations and litter mass.
怀孕和哺乳期间需要大量钙来支持胎儿和新生儿的骨骼生长及钙化。在这些阶段钙供应不足会导致繁殖失败或后代健康受损。在繁殖期间，雌性哺乳动物会经历众多生理变化，包括为保证充足钙供应而进行的适应性变化。缺乏从比较角度分析这些生理变化的定量研究限制了我们解释和理解这些适应性变化的能力。在此，我们展示了对14种哺乳动物怀孕和哺乳期间骨转换及钙稳态变化相关研究的荟萃分析。我们对60项研究的荟萃分析表明，所有物种在怀孕和哺乳期间都有相似的生理变化模式，包括：（1）血清钙浓度降低；（2）骨组织流失；（3）血清降钙素和甲状旁腺激素浓度降低；以及（4）血清骨化三醇浓度升高，无论甲状旁腺激素浓度如何变化。此外，我们发现：（1）血清钙浓度与乳头数量之间存在负相关；（2）血清甲状旁腺激素浓度与窝仔质量之间存在负相关。
