Kutina A V, Makashov A A, Balbotkina E V, Karavashkina T A, Natochin Yu V
Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, Saint Petersburg, 194223 Russia.
Acta Naturae. 2020 Jan-Mar;12(1):73-83. doi: 10.32607/actanaturae.10943.
The nonapeptides of neurohypophysis, vasotocin and mesotocin, detected in most vertebrates, are replaced by vasopressin and oxytocin in mammals. Using bioinformatics methods, we determined the spectrum of receptor subtypes for these hormones in mammals and their physiological effects in the kidneys of rats. A search for sequences similar to the vertebrate vasotocin receptor by proteomes and transcriptomas of nine mammalian species and the rat genome revealed three subtypes of vasopressin receptors (V1a, V1b, and V2) and one type of oxytocin receptors. In the kidneys of non-anesthetized rats, which received a water load of 2 ml per 100 g of body weight, three effects of vasopressin were revealed: 1) increased reabsorption of water and sodium, 2) increased excretion of potassium ions, and 3) increased excretion of sodium ions. It has been suggested that each of the effects on the kidney is associated with selective stimulation of the vasopressin receptor subtypes V2, V1b, and V1a depending on the concentration of nonapeptide. In experiments on non-anaesthetized rats with a water load, the injection of oxytocin reduces the reabsorption of solute-free water in the kidneys and increases the excretion of sodium ions. The possible physiological mechanisms behind the realization of both effects with the participation of a single type of oxytocin receptors are being analyzed. Thus, the spectrum of activated receptor subtypes varies depending on the current concentration of neurohypophyseal hormones, as a result of which the predominant effect on renal function changes, which ensures precise regulation of water-salt homeostasis.
在大多数脊椎动物中检测到的神经垂体九肽、加压催产素和中催产素，在哺乳动物中被血管加压素和催产素所取代。我们使用生物信息学方法确定了这些激素在哺乳动物中的受体亚型谱及其在大鼠肾脏中的生理作用。通过对9种哺乳动物和大鼠基因组的蛋白质组和转录组进行搜索，寻找与脊椎动物加压催产素受体相似的序列，结果发现了三种血管加压素受体亚型（V1a、V1b和V2）和一种催产素受体。在接受每100克体重2毫升水负荷的未麻醉大鼠的肾脏中，发现血管加压素有三种作用：1）水和钠的重吸收增加；2）钾离子排泄增加；3）钠离子排泄增加。有人提出，对肾脏的每种作用都与根据九肽浓度对血管加压素受体亚型V2、V1b和V1a的选择性刺激有关。在对接受水负荷的未麻醉大鼠进行的实验中，注射催产素可减少肾脏中无溶质水的重吸收，并增加钠离子的排泄。目前正在分析在单一类型催产素受体参与下实现这两种作用的可能生理机制。因此，激活的受体亚型谱会根据神经垂体激素的当前浓度而变化，其结果是对肾功能的主要影响发生改变，从而确保对水盐稳态的精确调节。
