[Conformational analysis of biologically active thyroliberin analogs by two-dimensional NMR spectroscopy].

Preferable conformations of thyrotropin-releasing hormone (TRH, Glp-His-Pro-NH2) and its analogues Glp-Glu(R)-Pro-NH2 (R = NHCH(CH3)CH2Ar), Glp-Gln-Abu-NH2, Dho-Gln-Abu-NH2 in DMSO solution are determined using two-dimensional 1H NMR spectroscopy (delta-J-correlated, COSY and NOESY). Torsion angles psi i and chi i for every amino acid were calculated on the basis of the spin-spin coupling constants 3JNH-C alpha H and 3JC alpha H-C beta H values. The NOESY data were used for selecting the peptide conformations realized in solution.

[Protective action of thyroliberin and its synthetic analog (PR-546) in craniocerebral trauma].

The effect of TRH and its synthetic analogue (PR-546) devoid of hormonal activity was studied in acute experiments on rats on the model of neurogenic lung edema caused by skull injury. It was proved that the preliminary (for 30 min before the injury) i/p introduction of TRH (in doses 0.5-1 mg/kg) and PR-546 (in doses 4-8 mg/kg) prevented the development of acute edema and the changes of blood gas compositions as well as disorders in breathing after skull injury.

[Cyclic analogs of ACTH fragments in self-stimulation and grooming behavior in rabbits].

In present study new cyclic fragments of ACTH EHFRWGKPVG--NH2 and KHFRWG--NH2 were investigated in organization of self-stimulation and grooming behaviour in rabbits. Intracerebroventricular injections of EHFRWGPVG--NH2 in doses of 0.1-2.

[Effects of femto- and picomolar concentrations of thyroliberin and tuftsin on the contractile activity of lymphatic vessels of the rat mesentery].

Thyrotropin-releasing-hormone (TRH) in concentration from I g/ml to 1.10(-10) micrograms/ml and tuftsin (T) (10 micrograms/ml to 1.10(-6) micrograms/ml) biomicroscopy were used in rats to show the ability to activate the contraction of lymphatic microvascular walls.

[Recovery of impaired respiratory activity in cats by thyroliberin analog (PR-546) devoid of hormonal properties].

Synthetic analogue thyroliberin (PR-546) devoid of hormonal activity, recovered respiration in conditions of hyperventilation, two-sided vagotomy and hypoxia, caused by the 40-70% bleeding. PR-546 (in doses 100-500 micrograms/kg) intravenously injected was shown to abolish diagram activity decreased effect after hyperventilation. Injection of PR-546 to vagotomized cats in 1.