[The influence of peptides on the morphofunctional state of old rats kidneys.]

More than a quarter of the elderly and senile age population suffers from kidney pathology. For this reason, a prophylaxis of kidney diseases with the safe and effective nephroprotectors is a priority of gerontology. An influence of polypeptide kidney complex (PKC), peptides AED, EDL, AEDG on the functional state of old rats kidneys was studied in research. Administration of PKC, peptides AED and EDL increased diuresis by 1,2-1,4 times. PKC and peptide AED reduced urine protein level and protein excretion by 1,5-2,8 times. PKC, peptides AED and EDL increased distal sodium transport by 1,2-1,3 times. Peptides AED and EDL increased sodium excretion by 1,3 and 1,6 times, respectively. Renal effects of peptide AEDG resulted in a reduction of glomerular filtration rate by 21%, decrease in urine protein level by 3,1 times and protein excretion - by 2,5 times. Peptide AEDG reduced absolute sodium reabsorption by 1,3 times and increased distal sodium transport by 1,4 times. Realization of glomerular-tubular and tubular-tubular balances is verified by correlation between glomerular filtration rate (GFR) and absolute sodium reabsorption, proximal and distal sodium reabsorption. In kidney tissue a stimulation of the antioxidant enzymes activity on the background of inhibition of the peroxidation processes intensity was observed, which in complex with morphological data evidences the absence of nephrotoxic effects. PKC, peptides AED, EDL and AEDG may be considered as nephroprotective agents in kidney aging.

Nephroprotective Effect of EDL Peptide at Acute Injury of Kidneys of Different Genesis.

EDL peptide produced a nephroprotective effect on experimental models gentamycin-induced nephropathy and ischemia/reperfusion kidney injury in rats. The nephroprotective effect of EDL peptide manifested in prevention of oliguria and retention azotemia, a decrease in proteinuria and sodium excretion, prevention of critical decrease in activities of antioxidant enzymes, suppression of LPO, and normalization of energy supply to kidneys cells. Our findings confirm the prospects of further studies of the nephroprotective properties of peptide EDL in various pathologies of the kidneys.

Peptides Restore Functional State of the Kidneys During Cisplatin-Induced Acute Renal Failure.

The effects of polypeptide complex from the kidney and short peptides AED, EDL, and AEDG on renal functions were studied in rats with cisplatin-induced acute renal failure. AED peptide decreased protein excretion and electrolyte concentration in the urine. Polypeptide complex from the kidney and peptides EDL and AEDG normalized diuresis, creatinine concentration in the urine and its excretion, glomerular filtration rate, and absolute resorption of sodium ions and reduced protein concentration in the urine and its excretion, the concentrations of sodium and potassium ions in the urine, and other parameters. EDL peptide produced was potent nephroprotective effect. It is known that the polypeptide complex of the kidney and short peptides restore the expression of signal molecules (marker of functional state of the kidneys), so these peptide substances can have nephroprotective effect during various renal pathologies.

[Renoprotective effects of statins under the conditions of acute renal failure, caused by rhabdomyolysis].

The experiment on white rats was targeted at the examination of influence of statins (atorvastatin, lovastatin, simvastatin) under the conditions of acute renal failure, caused by rhabdomyolysis. Renoprotective effects of statins were demonstrated by reduction of hyperazotemia and proteinuria and improvement of renal excretory function, which correlated with antioxidant properties of drugs.

[Main mechanisms of rhabdomyolysis-caused kidney injury and their correction by organospecific peptides].

The influence of the organospecific peptides--kidney tripeptides T-31 and T-35, pineal tetrapeptide epitalon on the main mechanisms of kidney injury caused by experimental rhabdomyolysis--toxic injury of tubular cells, development of oxidative stress and energetic misbalance, leading to significant disturbances of the functional state of kidneys and development of acute kidney failure was studied. The renoprotective effect of oligopeptides realized by impact on all of the indicated mechanisms of kidney injury and confirmed by correlation between them was estimated.

Effects of melatonin and epithalamin on the content of protein and lipid peroxidation products in rat cortex and hippocampus under conditions of acute hypoxia.

The effects of melatonin and epithalamin on the content of protein and lipid peroxidation products in the cortex and hippocampus of hypoxic rats were studied under conditions of acute hypobaric hypoxia equivalent to the altitude of 12,000 m. Pineal preparations reduced the intensity of free-radical processes in the brain exposed to acute hypoxia. Epithalamin more effectively than exogenous melatonin protected hippocampal neurons during acute hypoxia by reducing free-radical damage to lipids and proteins.

[Motility of rats exposed to an altered photoperiod in the open field test].

Motility of rats exposed to an altered photoperiod has been studied in the open field test. It has been shown that physical activity of rats kept in darkness declined. The correlation parameters of locomotor activity as compared to previous data changed in animals kept in continuous light.

[THE INFLUENCE OF THE MELATONIN ON THE CORRELATION BETWEEN THE INTENSITY OF THE ACCUMULATION OF THE OXIDATI-VE-MODIFIED PROTEINS CONTENT, ACTIVITY OF THE ANTIOXIDANT ENZYMES AND THE STATE OF PROTEOLYSIS IN THE BASAL NUCLEI OF THE BRAIN UNDER THE ACUTE HYPOXIA].

The effect of melatonin on the correlation between the intensity of the accumulation of the oxidative-modified protein content, activity of the antioxidant enzymes and the state of proteoly-sis in the basal nuclei (the nucleus caudatus, globus pallidus, nucleus accumbens, amigdaloid complex) of the brain under the conditions of acute hypoxia has been studied. Under the conditions of acute hypoxia in the basal nuclei an intensification of the protein peroxidation processes is observed, the activity of the antioxidant enzymes decreases, the intensity of the proteolysis increases. The injection of melatonin in a dose of 1 mg per kg of the body mass before the modeling of acute hypoxia results in the decreasing of protein peroxidation, increasing of the antioxidant enzyme activity and normalization of the parameters of proteolysis.

[Functional organization of a photoperiodic brain system]. / Funktsional'naia organizatsiia fotoperiodicheskoi sistemy golovnogo mozga.

The neurofunctional system, which receives a photoperiod, is a photoperiodic brain system. As a part of chronoperiodic system of organism it is involved in perception and transfer of information about the main external Zeitgeber to the peripheral tissues. Such role of photoperiodic system allows it not only synchronize the chronorhythms of different somatic and visceral functions, but also realize the coordination and the modulation of adaptation mechanisms to the stressors influence. The present review is focused on the ways of conduction of photoperiodic information, role of suprachiasmatic nuclei of hypothalamus in endogenous oscillation of chronorhythms and pineal gland as a neuroendocrinal transducer; and also on characteristics of circadian and circannual parts of photoperiodic system. Special attention is given to vegetative part of photoperiodic system and melatonin--"the hormone of dark". It is supposed that adenosine, one of the humoral elements of photoperiodic system, is involved in transfer of duration of the light part of photoperiod. Due to presented data we have come to the conclusion that septohippocampal system is one of the center for saving photoperiodic information.

[The lateral septal nucleus: its morphological and functional organization and its role in the formation of chronorhythms]. / Lateral'noe iadro peregorodki mozga: morfologicheskaia i funktsional'naia organizatsiia, rol' v formirovanii khronoritmov.

The lateral septal nucleus (LSN) is the largest septal nucleus and occupies one of the most strategically important positions in the forebrain, connecting the structures of the limbic system with different sites of the brain stem. Such a situation obliges LSN not only to participate in the regulation, but also to implement overall coordination and modulation of various visceral and somatic functions. The review deals with the general characteristic of the septal complex, the functional morphology, pre- and postnatal ontogenesis, afferent and efferent connections, mediator and modulator nature of LSN fibers. Special attention is paid to the participation of LSN in the neuroendocrine regulation of the sexual system. On the basis of literature and our own experimental findings it is shown that the LSN is a chronoregulatory structure which is responsible for the biorhythmologic organization of the functions of the mammalian organism.

[The role on non-adrenergic regulation in the reaction of the rat pineal body to acute hypoxia and epithalamine administration]. / Rol' neadrenergicheskoi reguliatsii v reaktsii shishkovidnogo tela krys na ostruiu gipoksiiu i vvedenie épitalamina.

The influence of co-administration of alpha-methyl-p-tyrosine (inhibitor of catecholamine synthesis) and alpha-(+) beta-adrenergic antagonists under conditions of acute hypobaric hypoxia or pretreatment with epithalamin on cyclic nucleotide content in the pineal gland of juvenile male albino rats was investigated. Acute hypoxia was accompanied by increase of pineal level of cyclic nucleotides and administration of adrenoreceptor antagonists attenuated this effect. Pretreatment of animals with adrenoreceptor antagonists did not influence the effect of acute hypobaric hypoxia on pineal cyclic nucleotide content. This suggests involvement of non-adrenergic mechanisms into augmentation of pineal cyclic nucleotide level. Administration of epithalamin caused an increase of pineal cGMP. Administration of epithalamin to rats pretreated with adrenoreceptor antagonists increased pineal cGMP and to a lesser extent cAMP content. The latter suggests that epithalamin effect was not mediated via sympathetic innervation. It is concluded that non-adrenergic innervation and humoral regulatory mechanisms are obviously involved into activation of pineal gland under conditions of acute stress.

[Effect of acute hypoxia on the intensity of free radical processes in the basal nuclei of the brain, and the rat behaviour in the open field test under conditions of altered photoperiod].

The effect of acute hypoxia on the intensity of free radical processes in the basal nuclei (the nucleus caudatus, globus pallidus. nucleus accumbens. amygdaloid complex) of the brain, and the rat behaviour in the open field test has been studied under conditions of altered photoperiod. It has been shown that constant darkness levels the effect of acute hypoxia on the intensity of lipid peroxidation, preserves the activity of superoxide dismutase and catalase at a higher level, lowers the activity of glutathione peroxidase. Under light, the sensitivity of basal nuclei neurons to acute hypoxia is enhanced, the latter being reflected in intensification of lipid peroxidation at the expense of increased formation of dien conjugates. The activity of catalase at that considerably exceeds the level of even intact rats in all the structures. It has been established that an altered photoperiod modulates the effect of acute hypoxia on the parameters of rat's activity in the open field, the character of their change depending on the nature of a photophase change.

The state of peroxidation processes in the basal nuclei of the brain in conditions of an altered photoperiod.

The state of peroxidation processes in the basal ganglia (caudate nucleus, globus pallidus, nucleus accumbens, amygdalar complex) of the rat brain was studied in conditions of an altered photoperiod. The results showed that changes to the normal photoperiodicity led to metabolic changes in these brain structures. In conditions of constant light, the basal nuclei showed increased lipid and protein peroxidation processes, with increases in the intensity of fibrinolysis and proteolysis and decreases in the activities of antioxidant defense system enzymes. In conditions of constant darkness, there were changes in fibrinolytic and proteolytic processes which were in different directions in different structures, along with decreases in free-radical processes on the background of the accumulation of modified proteins.

Effect of melatonin on the relationship between lipid peroxidation and proteolytic activity in basal nuclei of rat brain during acute hypoxia.

We studied the effect of melatonin on the relationship between LPO intensity and proteolytic activity in basal nuclei (caudate nucleus, globus pallidus, amygdaloid complex, and nucleus accumbens septi) of rat brain during acute hypobaric hypoxia. Acute hypoxia was accompanied by LPO activation and increase in proteolytic activity. It should be emphasized that the intensity of proteolysis was higher in structures responding by more pronounced LPO activation (nucleus accumbens septi and globus pallidus). Intraperitoneal injection of 1 mg/kg melatonin 30 min before acute hypoxia inhibited LPO and prevented the increase in proteolysis in basal nuclei of the brain. The effect of melatonin was most pronounced in basal nuclei highly sensitive to acute hypoxia.

Effect of melatonin on cyclic nucleotide content and intensity of lipid peroxidation in the hippocampus and habenula of rats exposed to acute hypoxia.

Single intraperitoneal injection of melatonin in a dose of 1 mg/kg prevented accumulation of cGMP and intensification of lipid peroxidation in the hippocampus and habenula of rats exposed to acute hypobaric hypoxia (12,000 m). Changes in habenular content of cGMP suggest that melatonin prevents hypoxia-induced activation of heme-oxygenase.