Regulation of hemodynamic parameters under conditions of systemic administration of angiotensin II and angiotensin IV to rats after carotid glomectomy.

Systemic administration of angiotensin II was followed by an increase in systolic BP and HR in rats with carotid glomectomy, the time of attaining maximum values in treated animals was much higher than in sham-operated controls. Injection of angiotensin IV slightly reduced systolic BP in sham-operated animals and increased it in rats with carotid glomectomy. The involvement of the local renin-angiotensin system of the carotid body in systemic mechanisms of hemodynamics regulation is discussed.

Reduction of alcohol dependence in rats after carotid glomectomy.

Carotid glomectomy significantly reduced the degree of alcohol addiction in rats, which was induced over 12 weeks. After glomectomy, the mean weekly volume of alcohol consumed by alcoholic animals over 4 weeks was lower compared to the preoperation level, while water consumption significantly increased by the 3rd and 4th weeks after surgery. Control sham operation had no effect on ethanol and water consumption in alcoholic rats. Possible involvement of the local renin-angiotensin system in chemoreceptor cells of the carotid body into systemic mechanisms of alcohol dependence is discussed.

Comparative analysis of dipsogenic effects of systemic and intracerebral injection of angiotensin II to rats after carotid glomectomy.

Systemic administration of angiotensin II after carotid glomectomy produced a less pronounced dipsogenic effects (consumption of water and NaCl solution) compared to sham-operated control animals. Injection of angiotensin II into the lateral cerebral ventricles of the same glomectomized rats increased water and NaCl consumption to a level surpassing that of sham-operated animals. The number of drinking acts and comfortable grooming acts decreased in glomectomized animals after systemic administration of angiotensin II, but increased after its intracerebral injection compared to the control. The results confirm the hypothesis that carotid chemoreceptors, as the peripheral component of the renin-angiotensin system, participate in the mechanisms of angiotensin-induced thirst, "salt appetite", and associated behavioral forms (comfortable grooming) synergically with the central cerebral receptors.

Water and salt consumption and suppression of Angiotensin-induced thirst in rats after carotid glomectomy.

Carotid glomectomy in rats reduced daily water consumption and increased daily consumption of NaCl solution. Sham operation did not modify water and salt consumption. Intraperitoneal injection of angiotensin-II did not stimulate drinking motivation in the majority of rats subjected to carotid glomectomy. Injection of angiotensin-II to sham-operated and intact animals induced active consumption of both fluids during one hour. These results attest to the involvement of the carotid body in the regulation of consumption of water and sodium ions (the main elements of osmotic blood pressure) and the involvement of angiotensin-sensitive receptors of carotid body cells in the formation of thirst and salt appetite motivation, regulated by the renin-angiotensin system.

Formation of taste aversion and preference in protein synthesis inhibition in rats.

The investigation was devoted to the role of the synthesis of protein and peptide factors during the formation of chemosensory memory in rats. Two models of gustatory memorization were used: conditioned taste aversion (CTA), induced by the association of the taste of saccharine with a toxic injection of lithium chloride, and enhanced taste preference (ETP), induced by the influence of preliminary drinking of a saccharine solution on its repeat consumption. It was found that, under conditions of the inhibition of protein synthesis in the brain of 43% by cycloheximide and of 59% by 8-azaguanine, CTA does not form. ETP does not form under the influence of cycloheximide, but not [sic] of 8-azaguanine. A hypothesis was advanced regarding the participation of a varied spectrum of protein and peptide substances in the formation of taste aversion and preference. An influence of protein synthesis blockers on the process of retrieval of gustatory memory was not found.

[The formation of taste aversion and preference under conditions of protein synthesis inhibition in rats]. / Formirovanie vkusovogo otverganiia i predpochteniia v usloviiakh ingibirovaniia sinteza belka u krys.

The study is devoted to the role of protein synthesis in formation of chemosensory memory in rats. Two experimental models of taste memorizing were used, i.e., conditioned taste aversion (CTA) caused by association of succharin intake with being poisoned by lithium chloride, and increased taste preference (ITP) caused by the influence of primary consumption of succharin solution on its repeated intake. It was found out that CTA was not formed under conditions both of 43% inhibition of brain protein synthesis by cycloheximide and of 59% its inhibition by 8-azaguanine. Cycloheximide but not 8-azaguanine prevented formation of ITP. A proposal was made about participation of different spectra of protein and peptide molecules in formation of taste aversion and preference. The effect of protein synthesis inhibitors on the process of taste memory retrieval was not found.

[The peptidergic mechanisms controlling specialized appetites and taste afferentation]. / Peptidergicheskie mekhanizmy kontrolia spetsialirirovannykh appetitov i vkusovoi afferentatsii.

Were studied the peptidergic mechanisms of regulation of the specialized forms of alimentary behaviour, i.e. the "salt" and "carbohydrate appetites", and the control of taste afferentation in the process of sodium chloride and saccharose consumption. Saccharose consumption controlled with participation of cholecystokinin was found to be mediated by an increase of taste afferentation under the influence of this peptide. Specialized sodium chloride consumption is under the control of the peptides litorine and substance P and mediated by a selective intensification of taste afferentation under the influence of these peptides. Active immunization by litorin-albumin and substance P-albumin conjugates was carried out to gain a high level of endogenous antibodies to these peptides. Injections of capsaicin to newborn rats was done for a degeneration of the substance P-containing nerve fibers. The methods used confirmed the specific participation of these peptides in a systemic regulation of salt consumption and activity of the chemoreceptors of the tongue. Were analyzed the main principles of the peptidergic regulation of the specialized forms of alimentary behaviour and the role of chemosensory afferentation in a correction of the process of consumption of the substances.

[Changes in the activity of the taste receptor apparatus and the preference for a sodium chloride solution in newborn rats receiving capsaicin]. / Izmeneniia aktivnosti vkusovogo retseptornogo apparata i predpochteniia rastvora natriia khlorida u novorozhdennykh krys, poluchavshikh kapsaitsin.

Taste receptor organ activity and preference of sodium chloride solution in rats with deficit of substance P (SP) were studied. Total impulse activity of chorda tympani nerve of 7-8 week old rats was recorded under nembutal anesthesia. The taste responses to four solutions (sucrose, quinine sulfate, sodium chloride and citric acid) were decreased in rats injected with capsaicin in comparison with rats injected with vehicle. The rats injected with capsaicin preferred water to sodium chloride (two-bottle technique). On the contrary the rats injected with capsaicin preferred the salt solution. These data together with previous studies show the important role of peptide SP in taste receptor activity and "salt appetite".

Litorin and litorin-albumin conjugate as effective regulators of body temperature in rats.

Intraperitoneal injection of the bombesin-like peptide litorin (0.5 ml of a 10(-5) M solution) led to a short-lived decrease in the body temperature (maximum of 0.9 degrees C) of laboratory rats. In contrast, immunization with litorin conjugated to bovine serum albumin (BSA) led to an increase in body temperature from 36.6 +/- 0.1 to 37.2 +/- 0.1 degrees C that persisted for at least 4 weeks and which was probably due to the binding of endogenous litorin by the newly formed antibody. These results suggest that litorin is involved in the physiological regulation of thermal homeostasis. The temperature of control rats immunized with Freund's adjuvant and BSA without litorin fluctuated around normal at 36.6 +/- 0.1 degrees C over this period. Rat body weight increased evenly during the experiment in both the experimental animals and the two control groups. However, the volume of food intake in the hour following 24 h food deprivation was lower in rats immunized with conjugated litorin than in the control groups.

[Specific changes in the sodium chloride intake and activity of the taste receptor apparatus of rats administered the peptide litorin and its albumin conjugate]. / Spetsificheskoe izmenenie protsessa potrebleniia khlorida natriia i aktivnosti vkusovogo retseptornogo apparata u krys v usloviiakh vvedeniia peptida litorina i ego kon''iugata s al'buminom.

The role of bombesin-like peptide litorin in control of salt consumption was studied in rats. The influence of exogenous injection and binding of the endogenous litorin in the organism on the consumption of sodium chloride and sucrose solutions was analyzed in deprived rats in the process of 15-min. testing. It was found that intraperitoneal injection of 10(-6) - 10(-5) M of litorin led to an increase, and rats immunization by peptide conjugate with ox serum albumin--to a decrease of the consumption of salt solution, without changing the consumption of sucrose solution. Titres of antibodies to litorin in the plasma of rats immunized with the conjugate were higher than in the control. Intraperitoneal, subcutaneous or intranasal injections of 10(-5) M of litorin led to selective increase of gustatory responses (recorded from the chorda tympani) to tongue stimulation by salt and acid solutions not influencing the responses to quinine and sucrose in anesthetized rats. The study shows, that the peptide litorin selectively participates in the control of sodium chloride consumption. In the process of such control the increase of taste apparatus sensitivity to the sodium chloride is probably involved.

[The effect of taste deafferentation on the phenomenon of pre-exposure taste solutions in rats]. / Vlianie vkusovoi deafferentatsii na éffekt potrebleniia vkusovykh rastvorov posle predvaritel'nogo pred''iavleniia ikh krysam.

After 2-day pre-exposure of rats to sucrose, saccharin or sodium chloride pairing with water (a two-bottle technique) the animals were deprived of liquid for 48 hours. After the deprivation was over, the rats were exposed to the familiar solution (a one-bottle technique) for 15 minutes. The rats which had already tried the taste solutions drank them in a greater amount in the 15-minute test as compared to those which had not been exposed to the taste solutions. In rats with bilateral deafferentation of the tongue, the preliminary testing of saccharin and sodium chloride solutions did not produce any effect on the volume intake during the 15-minute test. The increasing influence of the pre-exposure to sucrose solution could be seen both in deafferentated and in control sham-operated rats. The role played by the gustatory apparatus at the early stages of liquid intake as well as the effect of taste on short-term memory are discussed.

[Blood levels of corticosterone, aldosterone, angiotensin and ACTH in rats after deafferentation of the tongue]. / Kontsentratsiia kortikosterona, al'dosterona, angiotenzina i AKTG v plazme krovi u krys posle deafferentatsii iazyka.

The influence of tongue deafferentation on the plasma level of sodium homeostasis-controlling hormones has been studied. Using radioimmunoassay, high corticosterone and aldosterone plasma levels were discovered in rats with tongue deafferentation, as compared to sham-operated controls. ACTH and angiotensin I plasma concentrations in deafferentated rats were the same as in sham-operated rats. The role of emotional factors of taste perception in sodium homeostasis control is being discussed.

[Effect of taste deafferentation on the preference for solutions of saccharose, saccharin and salt in rats]. / Vliianie vkusovoi deafferentatsii na predpochtenie rastvorov sakharozy, sakharina i soli u krys.

The preference of sucrose, saccharin and salt solutions to water was analyzed during 5 days in rats with bilateral section of the lingual nerve comprising the taste nerve--chorda tympani. In the process of the analysis of daily consumption and choice of solutions, different types of behavioural reactions were found: stable preference and change of preference. The number of rats preferring NaCl was greater among the animals with sectioned lingual nerve than among sham-operated control rats and rats with ligated ducts of submaxillary and sublingual salivary glands. The number of rats with the lingual nerve section preferring sucrose or saccharin solutions to water was equal to that among the sham-operated rats. At the same time the mean volume of sucrose solution taken in daily by rats with sectioned lingual nerve was twice as great as the volume of saccharin, drunk by the same animals. The role of taste in the process of choice and preference of NaCl to sweet solutions is discussed.

[Activating effect of cholecystokinin-pancreozymin on the taste-receptor system of the rat]. / Aktiviruiushchee vliianie kholetsistokinina-pankreozimina na vkusovoi retseptornyi apparat krys.

The effect of the intraperitoneal injection of 10(-5) M cholecystokinin-pancreozimin solution on the taste total impulse activity of the rat chorda tympani was studied. The taste responses to sodium chloride and sucrose increased within 5 min and responses to quinine increased within 30 sec after the peptide injection. Responses to citric acid solution did not augment significantly. The augmentation of the taste responses under peptide injection can be blocked by cutting the chorda tympani nerve or subepithelial administration of atropine solution.

[Biopotential amplifier with nonlinear volt-ampere characteristics for recording low-amplitude pulses]. / Usilitel' biopotentsialov s nelineinoi vol't-ampernoi kharakteristikoi dlia registratsii nizkoamplitudnykh impul'sov.

An amplifier with non-linear volt-ampere characteristics for recording low-amplitude nerve pulse activity is offered. It permits recording impulses with an amplitude exceeding the noise by 3-5 microV and afferent impulse activity of rat taste nerves.