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Biomedical subjects

I A Zakharova

Publications and source records attributed to I A Zakharova.

At least 19 recordsLinked to original sources

Spectroscopic, biological, and antitumor studies on N-ethyl- and N-propylimidazole platinum(II) complexes.

Platinum(II) halide complexes with N-ethylimidazole (N-EtIm) and N-propylimidazole (N-PropIm) of the Pt(L)2X2 and Pt(L)4X2 types (X = Cl, Br, I) were prepared and characterized by far infrared spectra, electronic spectra, and conductivity measurements. The inhibitorial activity of some complexes on the Ca,Mg-dependent ATPase and the antitumor studies of the Pt(L)4Cl2 derivatives have been investigated. Pt complexes are not inhibitory active in comparison to the same Pd complexes (if c = 10(-4) M). The LD50 in physiological solution for [Pt(N-EtIm)4]Cl2 X 2H2O and [Pt(N-PropIm)4]Cl2 are higher enough with respect to the cis platinum.

Animals↗

[Toxic, anaphylactoid, and sensitizing properties of mercaptoquinolinates, metals of the 8th and 3d group].

A study was made of sensitizing, toxic and anaphylactoid action of eitht compounds of metals belonging to groups VIII and III of the periodic system. It was established that the activity depends on the nature of the central atom in the electronic structure of a complex salt ligand. The mechanism of histamine release was shown to be similar to that of specific antigen and to be related to preservation of the respiratory processes, of the microtubular and cell cyclic nucleotide systems. The sensitizing action of the compounds was shown by the reactions of the immediate and delayed types. Moreover, its realization did not require the presence of high molecular carriers, thus indicating that the latter is formed in the body.

Allergens↗

Histamine releasing and histamine binding action of platinum and palladium compounds.

Platinum and palladium salts were shown to possess either histamine releasing or histamine binding properties. Both these effects were dependent on chemical structures of the tested compounds and might be drawn up in the following sequences; Pd greater than Pt, PtIV greater than PtII, NO2 greater than F greater than Cl greater than SCN greater than J, trans greater than cis. One of the possible mechanisms of anti-tumoral effect of platinum and palladium salts might be their marked histamine binding activity.

Animals↗

[Comparative study of the toxic, anaphylactoid, and sensitizing properties of 5-sulfo-8-mercaptoquinolinates of metals of the 8th and 3d groups of the periodic table].

Pronounced allergizing action of the compounds of group VIII metals of the periodic system, observed in occupational pathology and commencement of their wide clinical application as cancerostatic agents require a comprehensive study of the properties of these substances. Anaphylactoid, toxic and genuine sensitizing action of 5-sulfo-8-mercapto-quinolinates of group YIII metals and those of group III metals having similar properties was studied and compared with reference to 8 compounds. It was shown that histamine liberation from mast cells induced by these substances as well as inhibition of the respiration of mast cells depend on the central atom and electronic structure of the ligand. The mechanism of histamine liberation observed was similar to that of specific antigen and was related to the preservation of the respiratory processes, the system of microtubules and cell cyclic nucleotides. The compounds tested were also capable of sensitizing the animal in intracutaneous injection of the substance without exogenous carrier. Sensitization developed according to the reaction of both the immediate and delayed types.

Allergens↗

[Interaction of platinum and palladium 5-sulfo-8-mercaptoquinoline complexes with sarcoplasmic reticulum Ca2+-dependent ATPase].

5-Sulfo-8-mercaptoquinoline complexes of platinum and palladium (complexes I and II) effectively inhibit Ca2+-dependent ATPase from sarcoplasmic reticulum. However, in contrast to K2PtCl4, K2PdCl4 and other previously investigated platinum and palladium complexes, they do not interact with the thiol groups of the enzyme. The inhibiting effects of complexes I and II are reversible and competitive with respect to ATP. In aqueous solutions complexes I and II decrease the fluorescence of tryptophane with a simultaneous shift in fluorescence towards the long-wave region. The same effect is exerted by the complexes on the fluorescence of tryptophane residues in Ca2+-dependent ATPase preparations. An addition of tryptophane to the enzyme preparations preincubated with complexes I and II partly restores the enzyme activity. It is assumed that the inhibiting effect of complexes I and II is due to their non-covalent interactions with the trytophane residues vicinal to the ATPase center.

Animals↗

[Allergenic and anaphylactoid properties of carcinostatic compounds of platinum].

Different effects of platinum salts on the organism were studied comparatively. The toxic effect was estimated by LD50; the carcinogenic one--by the action on Ehrlich ascites tumor; the anaphylactoid effect was evaluated by the degree of the arterial pressure fall, the development of bronchospasm and an increased blood histamine level in cats under intravenous injection of platinum salts. The sensitization action of platinum salts was assessed on guinea pigs. All these effects are found to be dependent on the salts chemical composition, and they are manifested in an independent route.

Allergens↗

[Induction of a menadione-dependent respiratory shunt by a platinum complex].

Submitochondrial particles (SMP) from the bovine heart were treated with platinum complex--K [C2H4 PtCl3] (Zeize's salt); there occurred a menadion-dependent shunt, this being expressed in menadion stimulation of oxygen consumption under conditions of electron transport block with rotenon. This effect was observed only with the use in the capacity of a substrate of NAD.N2, but not of succinate. Menadion-dependent respiration induced with Zeize's salt was dicoumarol-sensitive, but was not inhibited by antimycin and cyanide, this differentiating it from menadionreductase shunt in the intact hepatic mitochondria.

Animals↗

[Inhibitory effect platinum and palladium complexes as indicator of conformational changes in sarcoplasmic reticulum membranes].

Inhibition of Ca2+-dependent ATPase of sarcoplasmic reticulum membranes (SRM) by platinum and palladium complexes is considerable enhanced during the incubation of these compunds with SRM preparations in the presence of small (10(-5) M) concentrations of ATP or ADP. AMP and nucleotides with non-adenine bases do not have inhibitory effect. To increase the sensitivity of Ca2+-dependent ATPase to platinum and palladium complexes under the action of ATP (but not ADP), the presence of free Ca2+-ions in the medium is required. In the absence of ATP Ca2+-ions do not affect the inhibiting effect of the complexes. The increase in pH of the medium up to 8.5 and the increase of temperature up to 45degree C sharply decrease the ATP ability to enchance the sensitivity of Ca2+-dependent ATPase to platinum and palladium compunds. It is assumed that the ATP ability to enhance Ca2+-dependent ATPase inhibition by platinum and palladium complexes is due to ATP-dependent structural changes in SRM, which increase the availability of certain groups of the enzyme to those compounds.

Adenosine Triphosphatases↗

[Prediction of infectious complications of eye penetrating wounds by R protein concentration in lacrimal fluid].

Analysis of the lacrimal fluid of normal subjects and patients after cataract extraction and with penetrating wounds of the eyeball showed fluctuations of the R protein concentration, which depended on the type of the injury and its complications. The authors propose using measurements of R protein in the lacrimal fluid as a prognostic criterion predicting the development of infectious complications in penetrating wounds of the eyeball.

Biomarkers↗

[Clinical evaluation of the effectiveness of combined use of local and general hypotensive agents in patients with glaucoma and hypertension].

Visual functions, hydrodynamics, and bloodflow in internal carotid arteries were evaluated in 60 patients with primary glaucoma and essential hypertension. Effects of systemic and local beta-adrenoblockers and combinations of local hypotensive agents with calcium antagonists and angiotensin-converting enzyme inhibitors were studied. Negative effect of a combination of local and oral beta-adrenoblockers and positive effect of a combination of local hypotensive agents with oral capotene were revealed. Capotene is recommended for the treatment of glaucomatous patients with essential hypertension.

Administration, Oral↗

[Inhibition of membrane-bound adenosine triphosphatase by platinum and palladium salts].

Inhibition capacity of platinum and palladium complexes is studied on membrane-bound ADTP. The degree of inhibition of the enzyme activity is determined by the nature of the central atom and by the electron density on it, as well as by the ligand donor-acceptor capacity, by its mobility. The configuration of the complex and the charge of complex ion are of importance. The acidoligands studied according to their inhibition effect can be arranged in the following line: NO2, Cl, Br, SCN, I, which is true both for platinum and palladium compounds. For palladium complexes this line coincides with the location of ligands according to their ability to draw off the electron density from the central atom while in case of platinum complexes it has an opposite course of relationship for platinum and palladium complexes, points to a different mechanism of their interaction with the enzyme.

Adenosine Triphosphatases↗