Section of Physiology and Pharmacology, Division of Veterinary Sciences, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.
Anim Sci J. 2024 Jan-Dec;95(1):e13940. doi: 10.1111/asj.13940.
Lactation is a characteristic physiological function of mammals and is important for nourishing infants and the dairy industry; however, the molecular mechanisms underlying the function remain to be elucidated. A technique to directly evaluate the quantity and quality of milk in mice is necessary for the study of the lactation mechanism in vivo. By measuring the changes in milk amount after different durations of milk accumulation (0-24 h) using a ductal cannulation technique and oxytocin supplementation, we estimated the milk production rate at a single mammary gland level. In addition, collected milk was available to assess milk quality, including creamatocrit, osmolarity, and concentrations of ions, lactose, and total protein. Moreover, as a proof of principle, the effects of intraductal administration of a hypertonic solution to the abdominal mammary gland were examined. This stimulation increased milk amount, possibly by osmosis, compared with the contralateral control gland. These results demonstrated that this method is useful for examining the lactation ability and mechanisms in vivo. Studies using this method will contribute to the further understanding of lactation mechanisms in mammals.
泌乳是哺乳动物的一种特征生理功能，对喂养婴儿和乳品业都很重要；然而，其功能的分子机制仍有待阐明。为了研究体内泌乳机制，有必要开发一种直接评估小鼠乳汁数量和质量的技术。我们通过使用导管插管技术和催产素补充，测量在不同的乳汁积累时间（0-24 小时）后的乳汁量变化，估计单个乳腺水平的乳汁生成率。此外，收集的乳汁可用于评估乳汁质量，包括乳脂球计数、渗透压和离子、乳糖和总蛋白的浓度。此外，作为原理验证，我们检查了向腹部乳腺的导管内给予高渗溶液的效果。与对侧对照腺体相比，这种刺激通过渗透作用增加了乳汁量。这些结果表明，该方法可用于体内检查泌乳能力和机制。使用该方法的研究将有助于进一步了解哺乳动物的泌乳机制。
