Suzuki K, Koizumi N, Hirose H, Hokao R, Takemura N, Motoyoshi S
Department of Veterinary Internal Medicine, Nippon Veterinary and Animal Science University, Tokyo, Japan.
Comp Med. 2000 Jun;50(3):277-80.
The objectives of the study reported here were to determine whether a change in the plasma arginine vasopressin (AVP) concentration occurred in lactating, compared with non-lactating rats and to examine the involvement of suckling with plasma AVP concentration.
Experiments were performed on 86 female Wister Imamichi rats, 12 weeks old at parturition, with fast lactation. On day 13 of lactation, AVP concentration and plasma osmotic pressure were measured in lactating and non-lactating rats.
Plasma AVP concentration was always higher in rats of the lactating groups than in non-lactating controls (1.06 +/- 0.28 pg/ml), and a conspicuous increase in AVP concentration was seen during the postsuckling period (1.70-0.61 pg/ml before vs. 2.56 +/- 1.31 pg/ml after suckling, P < 0.05). Plasma osmotic pressure in lactating rats with 12 pups (296.6 +/- 5.2 mOsmol/kg x H2O) was lower than that in rats of the removed control groups (306.7 +/- 5.7 mOsmol/kg x H2O).
On the basis of these results, it appears that "low plasma osmotic pressure-high AVP status" develops in the lactating period, similar to pregnancy, through resetting of the regulatory mechanism of the AVP system. It was concluded that suckling stimulation could release AVP, which could dilute the blood with water resulting in the increase in circulating blood volume.
本文报道的研究目的是确定与非哺乳大鼠相比，哺乳大鼠血浆中精氨酸加压素（AVP）浓度是否发生变化，并研究哺乳与血浆AVP浓度之间的关系。
对86只分娩时12周龄、哺乳快速的雌性Wister Imamichi大鼠进行实验。在哺乳第13天，测量哺乳和非哺乳大鼠的AVP浓度及血浆渗透压。
哺乳组大鼠的血浆AVP浓度始终高于非哺乳对照组（1.06±0.28 pg/ml），且在哺乳后阶段AVP浓度显著升高（哺乳前1.70 - 0.61 pg/ml，哺乳后2.56±1.31 pg/ml，P<0.05）。哺育12只幼崽的哺乳大鼠的血浆渗透压（296.6±5.2 mOsmol/kg·H₂O）低于去除幼崽的对照组大鼠（306.7±5.7 mOsmol/kg·H₂O）。
基于这些结果，似乎哺乳期通过重置AVP系统的调节机制，与妊娠相似，会出现“低血浆渗透压 - 高AVP状态”。得出的结论是，哺乳刺激可释放AVP，AVP可使血液用水稀释，从而导致循环血容量增加。
