[Renin-angiotensin system in the mechanisms of alcohol motivation]. / Renin-angiotenzinovaia sistema v mekhanizmakh alkogol'noi motivatsii.

The role of angiotensins in the mechanism of alcohol motivation was studied. Angiotensins were shown to be capable of regulating not only thirst and salt appetite, but also alcohol intake by stimulation of alcohol consumption in non-alcohol-dependent rats and suppression of alcohol motivational excitation in alcohol-dependent rats. The mechanism of thirsty stimulation by angiotensins differs from that of their regulation of alcohol uptake. Angiotensins provoke thirst and salt appetite by activation of saralasin-sensitive classical angiotensin-II receptors while the regulation of ethanol intake by angiotensins is not mediated by the same receptors and realized through the participation of the common fragments for all endogenous angiotensins-[3-7]-angiotensin-II.

[Angiotensins in the mechanisms of drinking, feeding and alcohol motivations]. / Angiotenziny v mekhanizmakh pit'evoi, pishchevoi i alkogol'noi motivatsii.

In the paper was described the influence of angiotensin-2, captopril, bestatin, and angiotensin-2-(3-7) fragment on drinking, feeding and alcohol directed behaviour. It was found that dipsogenic doses of angiotensin-2 could inhibit food and alcohol intake mostly by a suppression of food and alcohol motivations. Specific antagonist of "classical" angiotensin-2 receptors saralasin could not block angiotensin-2 effects. A significant decrease of food and ethanol intake was revealed after intraventricular injections of enzyme blockers captopril and bestatin, which increase endogenic levels of angiotensin-1 and angiotensin-3, and also angiotensin-2-(3-7). So was shown the ability of angiotensins to suppress the dominant food or alcohol motivations by the activation of some other but not the "classical" angiotensin-2 receptors. Was suggested the involvement of angiotensins in the coordination of the different kinds of functional systems to create the optimal conditions for realization of drinking behaviour.

[Effects of neuropeptide Y on rat body temperature in normal conditions and after ethanol administration]. / Vliianie neiropeptida Y na temperaturu tela krys v norme in na fone vvedeniia étanola.

It was shown that intracerebroventricular (icv) administration of 2 micrograms neuropeptide Y (NPY) increased the rectal temperature in rats 2.5 hours postinjection. During 5 days we analysed dynamics of the effect of NPY on alcohol-induced hypothermia in this particular interval. 2 micrograms of NPY were given daily 30 min prior to 25% solution of ethanol (3 g/kg weight rat) intraperitoneal injection. It was found that NPY can prevent the attenuation of alcohol hypothermia on the 3-d and 4-th injection day. It was supposed that the inhibitory effect of NPY on the development of alcohol tolerance may be due to the capacity of NPY to increase food behavior. So it's known that activation of other competitor motivation may inhibit the development of alcoholism.

[Alcohol motivation in rats under blockade of protein synthesis by cycloheximide]. / Alkogol'naia motivatsiia u krys v usloviiakh blokady sinteza belka tsiklogeksimidom.

The influence of protein blocker cycloheximide on the ethanol intake in alcohol-dependent rats was studied. It was found that intracerebroventricular as well as perifornical area hypothalamus injection of cycloheximide caused inhibition of ethanol consumption in alcohol-dependent rats, persisting for 5-9 weeks. The blockade action of cycloheximide was more strong after its injection in phase of decreased ethanol intake. At the same time it was shown an increase in water and food intake. The blockade action of cycloheximide on ethanol intake was not found in alcohol-dependent rats. These data indicate that some protein substances take part in mechanisms of organization of alcohol motivation and dependence.

[The effect of the aminopeptidase inhibitor bestatin on the enkephalin level in the rat brain]. / Vliianie ingibitora aminopeptidaz bestatina na uroven' énkefalinov v mozge krys.

Met- and leu-enkephalin contents in midbrain (including hypothalamus) and striatum of rats were determined by radioimmunoassay after bestatin (racemate) injection (200 g, i.c.v.). It was found that bestatin administration influenced the midbrain met-enkephalin content, values and directions of the changes observed being dependent upon the time after the injection. The data obtained confirm the participation of aminopeptidase in enkephalin inactivation and present evidence for the possibility of regional variations of enkephalin catabolism pathways in the brain.

[Angiotensin II in the organization of rat feeding behavior]. / Angiotenzin-II v organizatsii pishchevogo povedeniia krys.

Intraventricular injection of angiotensin-II (100 ng) increased the latency period and decreased the amount of food intake in the hungry rats. Preliminary administration of saralasin (100 ng) blocked the inhibitory effect of angiotensin-II on food consumption. In contrast to the above mentioned intraperitoneal injection of angiotensin-II (10 ng/kg) 10 min before food and water admission results in the tendency to increase the food intake. And the same application of angiotensin-II 60 min before food and water admission increased by 49% of food intake in hungry rats. Saralasin (50 ng/kg) given prior to the angiotensin-II administration blocked the angiotensin-II effects. Moreover a significant decrease in the food intake was found after intraperitoneal injection of saralasin only. No significant changes in the drinking behavior in response to the intraventricular and intraperitoneal drugs administration were registered.

[The role of the perifornix area of the hypothalamus in forming alcoholic motivation in rats]. / Rol' perifornikal'noi oblasti gipotalamusa v formirovanii alkogol'noi motivatsii u krys.

In rats with alcohol motivation on the model of water deprivation with substitution of water for 20% ethanol solution, motivatiogenic "drinking centres" of the hypothalamus initiate in response to electro- and chemostimulation (acetylcholine) behavioural reactions of search and taking of alcohol and not of water. Electrolytic ablation of "thirst centres" of the perifornical hypothalamus area in rats with a formed attraction to alcohol is accompanied by a decrease of its taking during 3-5 days of observation. Microinjections of dipsogenic peptide angiotensin II, unlike acetylcholine administration, do not initiate taking of water or alcohol, but elicit only appearance of orienting-investigating, alimentary, sexual and other behavioural reactions. It is suggested that formation of alcohol motivation in these conditions is connected with a change of neurophysiological and neurochemical properties of the hypothalamus "thirst centres" initiating an active search and taking of alcohol and not of the water in rats with experimental alcoholism.

[Comparative analysis of the drinking behavior of rats after microinjections of angiotensin II and bradykinin into the cerebral ventricles and instillations on the conjunctiva of the eye]. / Sravnitel'nyi analiz pit'evogo povedeniia krys pri mikroin''ektsiiakhangiotenzina-II i bradikinina v bokovye zheludochki mozga i instillatsiiakh ikh na kon''iunktivu glaza.

The effects of angiotensin-II and bradykinin intracerebroventricular microinjections and instillations on the conjunctiva on water and alcohol consumption in rats were compared. The identical effects of peptide instillations on the conjunctiva and intracerebroventricular microinjections were demonstrated. Dipsogenic doses of angiotensin-II for instillations on the conjunctiva in intact rats were greater than or equal to 10 micrograms. At the same time the effective peptide doses in drinking rats were similar to intracerebroventricular drug doses.

[Effect of beta-lipoprotein derivatives on the drinking and feeding behavior of rats]. / Vliianie riada proizvodnykh beta-lipotropina na pit'evoe i pishchevoe povedenie krys.

The effects of some previously unexplored beta-lipotropin derivatives (fragments of beta-MSH 4-7 and 5-8 corresponding to fragments of beta-lipotropin 40-43, 41-44; an enkephalin analog--an enkephalin-like tetrapeptide Tyr-D-Ala-Gly-Phen-NH2) on drinking and food behavior of rats were studied and compared. beta-MSH 5-8 was found to possess a remarkable dipsogenic action but to produce no effect on food intake in rats. At the same time a structurally related analog beta-MSH 4-7 and enkephalin-like tetrapeptide did not alter drinking behavior of animals, exerting, however, a substantial satiating action on hungry rats and initiating food behaviour in fed animals. The effects of the peptides on drinking and food behavior appeared long-term, persisting for 14-16 days and even up to 4-4.5 months upon administration of the enkephalin-like tetrapeptide. The data obtained suggest that the structural similarity of peptides does not always determine the common characteristics of their physiological effects which depend to a considerable degree on the initial food motivation.

[Effect of an enkephalin-like tetrapeptide on the food instrumental behavior of rats]. / Vliianie énkefalinopodobnogo tetrapeptida na pishchevoe instrumental'noe povedenie krys.

An enkephalin-like tetrapeptide (subcutaneous, intraperitoneal and intraventricular injections) disturbs the goal-oriented food instrumental behavior of rats by decreasing the number of adequately performed instrumental reactions. In addition to these disorders, intraventricular microinjections entail an increase in the number of inadequate, incomplete behavioral reactions. Besides, injection of the tetrapeptide evokes specific disorders of motor activity, which manifest in the occurrence in rats of stretches, "duck-like step", motor stereotypy, arching of the tail, changes in the tone of abdominal muscles, etc. The tetrapeptide effects described were not inhibited by narcan, remaining unchanged for 3.5-5 months following a single injection of the tetrapeptide.

[Role of angiotensin II in the mechanisms of ethanol consumption regulation in rats]. / Rol' angiotenzina-II v mekhanizmakh reguliatsii potrebleniia étanola u krys.

The hypothalamohypophyseal and renin-angiotensin systems of rats were studied in health, during long-term alcoholization and formation of artificial alcohol motivation. It was disclosed that a single intracerebral administration of angiotensin-II had a long-term (for 1--2 weeks) inhibitory effect on alcohol consumption in rats. At the same time a decrease in the activity of the vasopressin-synthesizing neurosecretory cells of the hypothalamic supraoptic nucleus and Hering's bodies as well as compensatory activation of the peripheral parts of the renin-angiotensin system were demonstrated. Apparently, the inclusion of ethanol metabolites in the normal brain metabolism appreciably changes the role of angiotensin-II in hypothalamohypophyseal and renin-angiotensin system functions.