Low-molecular synthetic peptides with non-narcotic type of analgesia: comparative study and mechanism of analgesic activity.

The group of synthetic low-molecular peptides exhibiting profound analgesic activity was developed by modifying the salmon calcitonin molecule fragment sCT, which retains the previously reported analgesic activity of the full-sized molecule. The mechanism of analgesic action of these synthetic oligopeptides has been investigated and their analgesic effect was compared with analgesic activity of ketorolac tromethamine, one of the strongest non-steroidal anti-inflammatory drug painkiller. It was demonstrated that the analgesic effect of the developed synthetic oligopeptides was associated with the specific binding of the clathrin heavy chain.

Low doses of ethanol decrease the activity of the angiotensin-converting enzyme in the aorta of aging rats and rats treated with a nitric oxide synthase inhibitor and dexamethasone.

In the present study, the activity of ACE (angiotensin-converting enzyme) in the aorta of senescent rats and rats treated with the NOS (NO synthase) inhibitor L-NAME (NG-nitro-L-arginine methyl ester) or dexamethasone and the effect of low doses of ethanol (0.2-1.2 g/kg of body weight, daily for 8-12 days) on this activity were studied.

Distribution of the activity of the angiotensin-converting enzyme in the rat aorta and changes in the activity with aging and by the action of L-NAME.

The activity of the angiotensin-converting enzyme (ACE) of the inner surface (the endothelium surface) of rat aorta sections has been studied depending on their distance from the aortic arch, age of rats, and the duration of treatment of rats with the NO synthase inhibitor, N (ω)-nitro-L-arginine (L-NAME). The activity of ACE of aorta sections was determined by measuring the hydrolysis of hippuryl-L-histidyl-L-leucine and was expressed as picomoles of Hip-His-Leu hydrolyzed per minute per square millimeter of the endothelium surface. It was found that the ACE activity considerably varies along the aorta of young rats.

Determination of reactive oxygen and nitrogen species in rat aorta using the dichlorofluorescein assay.

A method for the determination of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in macroscopic sections of vessels has been developed on the basis of the dichlorofluorescein (DCF) assay. DCF was measured by fluorescence in extracts of vessels. The main artifact of the method is the oxidation of dichlorodihydrofluorescein (DCFH(2)) which is released from vessels together with DCF during the extraction procedure.

Detection of reactive oxygen species induced by radiation in cells using the dichlorofluorescein assay.

The goal of this study was to determine the amount of reactive oxygen species (ROS) that arises inside cells irradiated in medium containing blood serum using the 2'7'-dichlorofluorescein (DCF) assay. DCF fluorescence in cells and medium was recorded on an MF44 Perkin Elmer fluorimeter, and fluorescence in cells only was recorded on a Partec flow-through cytometer. Human larynx tumor HEp-2 cells and lympholeukosis P388 cells were irradiated with X rays at a dose rate of 1.

Modification of multidrug resistance of tumor cells by ionizing radiation.

Purpose: The effect of ionizing radiation on multidrug resistance (MDR) of human larynx cancer HEp-2 cells has been investigated. We studied the dependence of the radiation effect on radiation dose, time after irradiation and cell density.

Methods: MDR was determined from an increase in cell sensitivity to daunorubicin, taxol and vincristine by the inhibitors of multidrug resistance cyclosporin A and avermectin B(1), and from the suppression by cyclosporin A of the transport of rhodamine 123 out of the cells.