[Comparison of reabsorption of osmotically free water in the bud and energy of interaction of vasotocin analogs with a V2-receptor].

The calculated values of the binding energy of nonapeptides with receptors in docking with their influence on reabsorption of osmotically free water in a rat bud in vivo were compared. Vasotocin and some its analogs were intramuscularly introduced to non-narcotized rat females of the Wistar line in doses from 0.1 pmol to 0.

Weak toxin WTX from Naja kaouthia cobra venom interacts with both nicotinic and muscarinic acetylcholine receptors.

Iodinated [125I] weak toxin from Naja kaouthia (WTX) cobra venom was injected into mice, and organ-specific binding was monitored. Relatively high levels of [125I]WTX were detected in the adrenal glands. Rat adrenal membranes were therefore used for analysis of [125I]WTX-binding sites.

Steered molecular dynamics simulations of cobra cytotoxin interaction with zwitterionic lipid bilayer: no penetration of loop tips into membranes.

Cobra cytotoxins, small proteins of three-fingered toxin family, unspecifically damage membranes in different cells and artificial vesicles. However, the molecular mechanism of this damage is not yet completely understood. We used steered molecular dynamics simulations to study the interaction of cardiotoxin A3 from Naja atra cobra venom with hydrated 1-palmitoyl-2-oleoyl-1-sn-3-phosphatidylcholine (POPC) bilayer.

[Effects of vasotocin analogs on excretion of Na+, K+, and Mg2+ ions via rat kidney].

Experiments on rats showed that the intramuscular injections of arginine-vasotocin (AVT), 1-deamino-arginine-vasotocin (1dAVT) or 1-deamino-1-monocarba-arginine-vasotocin (1dlmcAVT) at a dose of 5 x 10(-11) mole per 100 g body weight increase renal excretion of Na+, K+, and Mg2+. Antagonist of V1 receptors (OPC-21268) decreases the effect of 1dAVT nonapeptides on renal excretion of the studied ions. A model of VIb-receptor is constructed and a correlation is shown between the energy of interaction of the V1b-receptor and the natriuretic effect of the studied vasotocin analogs.

[Vasopressin receptors: structure and stimulation by 1-deamino-arginine-vasotocin in rats].

In experiments on non-anesthetized female Wistar rats, it has been shown that injection of 1-deamino-arginine-vasotocin (1dAVT) increases sodium excretion and solute-free water reabsorption. Antagonists of V1-receptors (OPC-31260, Otsuka Pharmaceutical Co., Ltd.