Alekseev N P, Markov A G, Tolkunov Y A
Laboratory of Physiology of Secretory Processes, St. Petersburg University, Russian Federation.
J Dairy Res. 1992 Nov;59(4):469-78. doi: 10.1017/s0022029900027138.
The reaction of secretory epithelium and myoepithelial cells in the alveoli to hand milking and i.v. injection of oxytocin and catecholamines was studied in lactating goats. The reaction of secretory cells was assessed by changes in the transepithelial (blood-milk) potential difference (PD), and the contractile reaction of myoepithelial cells by the growth of intramammary pressure (IP). The initial value of PD was 24.6 +/- 0.6 mV, that of IP 3.32 +/- 0.08 kPa (24.9 +/- 0.6 mmHg). Milking and oxytocin administration caused a rise in PD and an increase in IP. After noradrenaline and adrenaline injections two-phase PD changes and a short-term rise in IP were recorded. Isoproterenol, a beta-agonist, caused a rise in PD but did not affect IP. Phenylephrine, an alpha-agonist, caused two-phase and one-phase changes in PD. Simultaneously, a rise in IP was recorded. The results show that the reaction of the mammary gland to the substances administered is complex. Myoepithelial and secretory cells respond differently to short-term rises in the level of mediators and hormones in the blood.
在泌乳山羊中研究了肺泡中分泌上皮细胞和肌上皮细胞对人工挤奶以及静脉注射催产素和儿茶酚胺的反应。通过跨上皮（血 - 乳）电位差（PD）的变化评估分泌细胞的反应，通过乳腺内压力（IP）的升高评估肌上皮细胞的收缩反应。PD的初始值为24.6±0.6 mV，IP的初始值为3.32±0.08 kPa（24.9±0.6 mmHg）。挤奶和给予催产素会导致PD升高和IP增加。注射去甲肾上腺素和肾上腺素后，记录到PD出现双相变化以及IP短期升高。β - 激动剂异丙肾上腺素会导致PD升高，但不影响IP。α - 激动剂去氧肾上腺素会导致PD出现双相和单相变化。同时，记录到IP升高。结果表明，乳腺对所给予物质的反应是复杂的。肌上皮细胞和分泌细胞对血液中介质和激素水平的短期升高反应不同。
