Calcium and glucose uptake in rat small intestinal brush-border membrane vesicles. Modulation by exogenous hypercortisolism and 1,25-dihydroxyvitamin D-3

The effect of exogenous hypercortisolism and 1,25-dihydroxyvitamin D-3 on small-intestinal calcium and glucose transport in the rat was studied at the level of brush-border membrane vesicles generated from isolated villous cells by a freeze-thaw procedure. At 5 X 10(-5) M extravesicular calcium, initial uptake rates in vesicles prepared from triamcinolone-treated adult rats were decreased by 30% after 5 days. Since calcium ionophore A23187 virtually abolished the difference in calcium uptake, triamcinolone appeared to affect calcium channel density or activity rather than intravesicular binding capacity. Kinetic analysis showed that a decrease in Vmax of a saturable calcium transport system could entirely account for the diminished rate of vesicular calcium uptake. Calcium transport rates could be partially restored by in vivo administration of 1,25-dihydroxyvitamin D-3 at a dosage which did not affect vesicular calcium uptake in control animals. Conversely, sodium-driven glucose accumulation in brush-border vesicles from triamcinolone-treated rats was stimulated by 50-70% after 36 h and appeared insensitive to vitamin D. A specific triamcinolone action on the glucose carrier itself rather than on the driving force of the sodium gradient was indicated by (i) a similar stimulation of glucose transport under equilibrium exchange conditions and (ii) an opposite effect of triamcinolone on sodium-driven alanine transport. The triamcinolone-induced changes in calcium and glucose uptake were not accompanied by a gross alteration of membrane integrity in vitro or by major alterations in vesicular protein composition, intravesicular glucose space and sucrase or alkaline phosphatase activity. The modification of vesicular transport properties is discussed in relation to the vitamin D-antagonized inhibition of intestinal calcium uptake and the stimulation of glucose absorption in response to supraphysiologic amounts of glucocorticoids observed in intact epithelium.     

The effect of local anesthetics on calcium transport across the rat and turtle small intestine

Procaine at different concentrations enhanced significantly (P less than 0.01) calcium accumulation in rat intestinal cells, whereas the same concentrations of procaine inhibited significantly (P less than 0.01) calcium uptake by the turtle small intestine. Unidirectional calcium influx across the rat small intestine was significantly enhanced (P less than 0.001) by the presence of procaine in the preincubation medium. However, procaine had no effect on calcium influx across the turtle intestinal cells. The cell water content and the cell volume were not altered by preincubating the intestinal tissues with procaine in both animals.     

Age-dependence of metabolism in mussels Mytilus edulis (L.) from the White Sea

Age structure, natural mortality and growth, as well as age- and size-dependent changes in parameters of energy metabolism were studied in blue mussels Mytilus edulis (L.) from the White Sea. Mussels were sampled in August (Summer sample, SS) and October (Autumn sample, AS) and contained animals of three size groups, 2-9 years old. Field data showed an increase of mortality of mussels and strong decrease in growth rates after 6 years of age. Absolute tissue growth increment (AI) reconstructed from winter growth marks on the shells decreased with age and was strongly size-dependent, while relative tissue growth increment (RI) did not depend on size of the animals. Respiration rates and citrate synthase activity demonstrated power regression versus tissue weight with regression coefficients -0.231 and -0.170, respectively. After weight correction both parameters showed a decrease with increasing age. ATP and phosphagen levels also showed a pronounced decrease in animals older than 5-6 years despite considerable differences in the absolute values of both parameters in SS and AS. pH(i) in mussels was also age-dependent and decreased with increasing age after 5 years. In air exposed mussels, pH(i) was reduced only at young age such that pH(i) was low and constant within the whole age range. Our data give evidence that aerobic metabolic rate in M. edulis from the studied population declines when animals reach an age of about 6 years. The decrease in oxygen consumption reflects the drop in mitochondrial respiration, which is mirrored by the decrease in CS activity. A concomitant fall in ATP turnover may include a downregulation of the mechanisms of acid-base regulation. pH(i) will then approach equilibrium indicated by lower pH(i) values in older animals. Our data suggest that intrapopulational comparisons of physiological parameters in mussels should take into account age composition of compared samples.     

Calcium and glucose uptake in rat small intestinal brush-border membrane vesicles. Modulation by exogenous hypercortisolism and 1.25-dihydroxyvitamin D-3

The effect of exogenous hypercortisolism and 1,25-dihydroxyvitamin D-3 on small-intestinal calcium and glucose transport in the rat was studied at the level of brush-border membrane vesicles generated from isolated villous cells by a freeze-thaw procedure. At 5 · 10^?5 M extravesicular calcium, initial uptake rates in vesicles prepared from triamcinolone-treated adult rats were decreased by 30% after 5 days. Since calcium ionophore A23187 virtually abolished the difference in calcium uptake, triamcinolone appeared to affect calcium channel density or activity rather than intravesicular binding capacity. Kinetic analysis showed that a decrease in V_max of a saturable calcium transport system could entirely account for the diminished rate of vesicular calcium uptake. Calcium transport rates could be partially restored by in vivo administration of 1,25-dihydroxyvitamin D-3 at a dosage which did not affect vesicular calcium uptake in control animals. Conversely, sodium-driven glucose accumulation in brush-border vesicles from triamcinolone-treated rats was stimulated by 50–70% after 36 h and appeared insensitive to vitamin D. A specific triamcinolone action on the glucose carrier itself rather than on the driving force of the sodium gradient was indicated by (i) a similar stimulation of glucose transport under equilibrium exchange conditions and (ii) an opposite effect of triamcinolone on sodium-driven alanine transport. The triamcinolone-induced changes in calcium and glucose uptake were not accompanied by a gross alteration of membrane integrity in vitro or by major alterations in vesicular protein composition, intravesicular glucose space and sucrase or alkaline phosphatase activity. The modification of vesicular transport properties is discussed in relation to the vitamin D-antagonized inhibition of intestinal calcium uptake and the stimulation of glucose absorption in response to supraphysiologic amounts of glucocorticoids observed in intact epithelium.     

Reduction of K+-Stimulated 45Ca2+ Influx in Synaptosomes with Age Involves Inactivating and Noninactivating Calcium Channels and Is Correlated with Temporal Modifications in Protein Dephosphorylation

The voltage-dependent calcium uptake in rat brain synaptosomes was measured under conditions in which [Ca2+]o/[Na+]i exchange was minimized to characterize the voltage-sensitive calcium channels from rats of different ages. In solutions of CaCl2 concentrations of less than 500 microM, the initial (5-s) calcium uptake declined by approximately 20-50% in 12- and 24-month-old rats relative to 3-month-old adults. Depolarization of synaptosomes from 3-month-old rats in a calcium-free medium or in the presence of 0.5 mM CaCl2 led to an exponential decline of the calcium uptake rate after 20 s (voltage- or voltage-and-calcium-dependent inactivation) to approximately 66 and 34% of the initial value with a t1/2 of 1.6 or 0.7 s, respectively. The presence of 1 microM nifedipine resulted in a 15-25% reduction of 45Ca2+ uptake rates, which appeared to affect noninactivating calcium channels, but addition of the calcium channel agonist Bay K 8644 was without effect. In 24-month-old rats, inactivation of 45Ca2+ uptake in calcium-free media was nondetectable, and in the presence of 0.5 mM CaCl2, the rate and extent of inactivation were also much lower than in 3-month-old animals (the t1/2 was 0.9 s, and the calcium uptake rate at 20 s was 55% of its initial value). Moreover, the presence of 1 microM nifedipine was without effect on initial calcium uptake or inactivation in synaptosomes from 24-month-old rats. These results indicate that the decrease in calcium channel-mediated 45Ca2+ uptake involves an inhibition or block of both dihydropyridine-resistant and -sensitive calcium channels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of theophylline and theobromine on cell respiration and calcium transport in isolated rat liver mitochondria

The influence of theophylline and theobromine on cellular respiration and on membrane transport of calcium has been studied in isolated rat liver mitochondria, using oxygen and Ca2+ selective electrodes. A linear decrease in respiratory coefficients, in the total amount and rate of "extra" oxygen consumption induced by ADP is observed with drug concentration. Theobromine does not show any appreciable effect on these respiratory parameters, but this result is similar to that observed with theophylline for the same concentration range. Calcium uptake coupled to respiration is inhibited by both drugs depending on their concentrations. Theobromine is more effective than theophylline. Calcium saturation of the mitochondria takes place in all cases after 36 +/- 2 s but only a 20% of the maximum calcium uptake observed in the absence of the drugs is determined in the presence of 15 mM theophylline or only 1.8 mM theobromine. Comparative studies show direct correlation between the pharmacological activities as stimulants of caffeine, theophylline and theobromine and their behaviour as inhibitors of calcium uptake coupled to respiration by mitochondria.     

The calcium and phosphorus content of the bone tissue in ovariectomized rats with a fracture of the tibia: the effect of vitamin K and vitamin D metabolites]

Calcium and phosphorus content in the bone tissue of ovariectomized rats with a shinbone fracture has been estimated. It was found out that unlike pseudo-operated animals whose fracture was accompanied by a decrease of calcium and phosphorus content and density in the right proximal epiphysis of the femur, in case of ovariectomized rats those parameters increased. Under those conditions a decrease in the epiphysis density and calcium and phosphorus content both in the shinbone and in the femur of the left extremity was similar both in pseudo-operated and ovariectomized rats. Administration of 1 alpha (OH)D3, 24R, 25(OH)2D3 and vitamin K to ovariectomized animals with a shinbone fracture produced no positive effect on the bone tissue, which anyhow, did not exclude a possibility of a positive effect in other doses and for a longer period of time.     

Ontogeny of mitochondrial calcium transport in spontaneously hypertensive (SHR) and WKY rats

The current studies were designed to investigate calcium uptake by intestinal jejunal sacs as well as in intestinal mitochondria of spontaneously hypertensive rats and their genetically matched WKY control rats. Kinetics of jejunal calcium uptake by jejunal sacs of adult SHR and WKY rats showed a significant decrease in Vmax of calcium uptake in SHR (227 +/- 24 versus 423 +/- 22 nmol.g tissue-1.3 min-1) compared to WKY rats P less than 0.001. To explore the intracellular handling of calcium by the intestinal mitochondria, calcium uptake was characterized by intestinal mitochondria before (suckling and weanling periods) and after (adult period) development of hypertension. Calcium uptake by intestinal mitochondria was driven by ATP in the presence of succinate as a respiratory substrate. Calcium uptake was stimulated several fold by the presence of ATP compared to no ATP conditions. Maximal calcium uptake occurred between 15-30 min and was significantly greater in adult SHR and WKY rats compared to corresponding values in weanling and suckling rats. Maximal ATP dependent calcium uptake in adult, weanling and suckling WKY rats was significantly greater compared to corresponding mean values in each age group in SHR (P less than 0.001). Oligomycin (10 micrograms/mg protein) inhibited calcium uptake partially. Ruthenium red (0.25 microM), 1 mM sodium azide and 0.5 mM dinitrophenol inhibited calcium uptake by more than 80% in both SHR and WKY rats. Kinetic parameters for ATP stimulated calcium uptake at 10 s revealed a Vmax of 0.56 +/- 0.6, 3.46 +/- 0.23 and 3.95 +/- 0.52 nmol/mg protein/10 s in suckling, weanling and adult WKY rats.(ABSTRACT TRUNCATED AT 250 WORDS)     

Calcium uptake in rat liver mitochondria accompanied by activation of ATP-dependent potassium channel

The influence of potassium ions on calcium uptake in rat liver mitochondria is studied. It is shown that an increase in K+ and Ca2+ concentrations in the incubation medium leads to a decrease in calcium uptake in mitochondria together with a simultaneous increase in potassium uptake due to the potential-dependent transport of K+ in the mitochondrial matrix. Both effects are more pronounced in the presence of an ATP-dependent K+-channel (K+(ATP)-channel) opener, diazoxide (Dz). Activation of the K+(ATP)-channel by Dz alters the functional state of mitochondria and leads to an increase in the respiration rate in state 2 and a decrease in the oxygen uptake and the rate of ATP synthesis in state 3. The effect of Dz on oxygen consumption in state 3 is mimicked by valinomycin, but it is opposite to that of the classical protonophore uncoupler CCCP. It is concluded that the potential-dependent uptake of potassium is closely coupled to calcium transport and is an important parameter of energy coupling responsible for complex changes in oxygen consumption and Ca2+-transport properties of mitochondria.     

Age-Related Features of Morphological and Functional Development of Myocardium in Children of Five to Nine Years

Age-related features of the morphological and functional development of the myocardium were studied by echo- (EchoCG) and electrocardiography (ECG) in 200 children five to nine years of age. The most intensive anatomical development of myocardium was observed at the age of five to seven years, and a significant increase in cardiac output was observed at the age of eight to nine years both in boys and girls. The ECG amplitude and time parameters significantly changed from of five to nine years of age and were most pronounced at the age of seven to eight years. Different changes in cardiac rhythm and excitation conduction as well as repolarization and metabolic disturbances in the myocardium were often observed at this age. Static physical exercise caused marked changes in bioelectric activity of the myocardium. Two types of central circulatory responses to static exercise were found: an increase and a decrease in cardiac output. The mechanisms of cardiac rhythm regulation, which caused an increase in the stroke volume as a response to exercise, were different in children from five to nine years old. At the age of five to six years the homeometric mechanism was a crucial factor in the increase in stroke volume as a response to exercise, and at the age of seven to nine years both homeo- and heterometric mechanisms of cardiac rhythm regulation were very important.     

Hypercalcemic effect of insulin in thyroparathyroidectomized alloxan-treated rats

The acute effect of a hypoglycaemic dose of 0.5 U/100 g BW insulin administered intramuscularly on calcium metabolism was investigated in fasted alloxan-treated rats. It was found that the hypercalcaemic effect of insulin was evident only in thyroparathyroidectomized (TPTX) and not in parathyroidectomized (PTX) rats. A subcutaneous administration of 180 MRC mU/100 g BW calcitonin abolished the calcium raising effect of insulin in TPTX rats suggesting a protective role of calcitonin against insulin action in intact rats. In an attempt to elucidate the mechanism of the calcium raising effect of insulin 45Ca administered intravenously was used to indicate the movement of calcium from the plasma pool. Insulin administration delayed the plasma 45Ca disappearance rate but had no effect on bone 45Ca uptake within 120 min. In contrast, insulin administration resulted in a 31% reduction of urinary 45Ca excretion while the urine volume remained unchanged. However, the insulin-induced reduction of urinary calcium excretion could not totally account for the calcium raising effect of insulin in TPTX animals.     

Sodium and calcium transport in cat red cells.

The transport of radioactive sodium and calcium in high sodium low potassium cat red blood cells has been studied under various experimental conditions. In these cells, calcium uptake was found to increase by 25-fold when cell volume was decreased from 1.0 normal to 0.55. Increasing cell volume from 1.0 to 1.1 normal was found to decrease calcium-uptake by 30%. N-ethylmaleimide, NEM, phloretin, colchicine, and vinblastine were found to inhibit Na-uptake by these cells. Among these four agents, phloretin was the most potent inhibitor of Na-influx. It appears that phloretin produces its effect through its interaction with the cell membrane and not with cell interior.     

Potentiation by propofol of the response of rat submandibular acinar cells to purinergic agonists

The effect of propofol (2,6-diisopropylphenol) on the intracellular concentration of calcium ([Ca(2+)](i)) and on the response of rat submandibular acini to purinergic agonists was studied. By itself, propofol (60 to 200 microM) slowly increased the [Ca(2+)](i) without affecting the production of inositol phosphates. The increase of the [Ca(2+)](i) involved for about 50% the mobilization of thapsigargin-sensitive intracellular calcium pools. The rest of the calcium originated from a pool distinct from mitochondria. Propofol also increased the uptake of extracellular calcium but not manganese by a mechanism inhibited by nickel. The variation of the [Ca(2+)](i) by propofol provoked a decrease of cell volume measured by light scattering. Propofol increased the effect of a maximal concentration of extracellular ATP on the [Ca(2+)](i). This interaction could be observed when propofol and ATP were added simultaneously to the medium but not when propofol had been removed from the medium before adding ATP. Among ATP analogs, propofol only increased the response to benzoyl-ATP (Bz-ATP). The blockade of P2X(7) receptors with oxidized ATP or Coomassie blue did not prevent the interaction between propofol and ATP. The effect of propofol could also be observed even when the concentration of ATP(4-) was decreased by extracellular magnesium to such a level that only P2X(4) receptors could possibly be activated by the nucleotide. Propofol had no effect on the uptake of manganese, the formation of pores and the activation of phospholipase D in response to a P2X(7) agonist. These results exclude an interaction with this receptor.It is concluded that, in rat submandibular acini, propofol can increase the [Ca(2+)](i) and decrease the cell volume. Propofol can also modulate the activation of P2X(4) receptors by extracellular nucleotides. These effects are observed at concentrations of propofol reached during the induction of anesthesia and might explain why hypersalivation has been reported as one of the side-effects of propofol.     

Utilization of the coconut shell of babaçu (Orbignya sp.) to produce cement-bonded particleboard

The zinc biosorptive capacity of the brown seaweed Sargassum sp. (Phaeophyceae) was studied in the presence or absence of competing calcium ions, using a continuous system with tubular fixed-bed reactors. In order to detect the effect of calcium on zinc biosorption, a 130 mg/l zinc solution was used, and calcium was added at 50-340 mg/l. The potential zinc biosorptive capacity of the biomass was markedly influenced by the presence of ionic calcium. Zinc sorption decreased with increasing calcium concentrations, as expressed by zinc uptake rates. Calcium was effectively recovered only during the initial stages of the process, as expressed by the decrease in its uptake rates. Calcium uptake rates were also much higher than zinc uptake rates, indicating that calcium was preferentially recovered when compared to zinc.     

Age influences on intestinal sugar absorption

Intestinal absorption of sugars show differences depending on animals age. This is demonstrated using in vivo and in vitro techniques. The age dependence relationship is present in animals of different species such as avian, rodents and ruminants. In chicken the intestinal sugar transport increases after hatching and attains its maximum capacity by the first week of life. The D-glucose and D-galactose uptake is greater in young rats, maximum at 21 days, while it decreases thereafter. The total capacity of the small intestine of adult sheep for sugar absorption was approx. 25% of that for lambs less than 1 week of age. The differences observed in intestinal absorption of sugars at different ages could be attributed to differences in sodium and calcium transport. Other authors assume that it is induced by morphological differentiation during intestinal development.     

Furosemide and Ca2+ affect 86Rb+ efflux from pancreatic beta-cells by different mechanisms

The interaction between furosemide, calcium and D-glucose on the 86Rb+ efflux from beta-cell-rich mouse pancreatic islets was investigated in a perifusion system with high temporal resolution. Raising the glucose concentration from 4 to 20 mM induced an initial decrease in 86Rb+ efflux, which was followed by a steep increase and then a secondary decrease. Removal of extracellular calcium increased the 86Rb+ efflux at 4 mM D-glucose but reduced it at 20 mM. The initial biphasic changes in 86Rb+ efflux induced by 20 mM D-glucose were inhibited by calcium deficiency. Furosemide (100 microM) reduced the 86Rb+ efflux rate both at 4 and 20 mM D-glucose and the magnitudes appeared to be similar at either glucose concentration. Furosemide (100 microM) reduced the glucose-induced (10 mM) 45Ca+ uptake but did not affect the basal (3 mM D-glucose) 45Ca+ uptake. However, the ability of furosemide (100 microM) to reduce the 86Rb+ efflux at a high glucose concentration (20 mM) was independent of extracellular calcium. The inhibitory effects of furosemide and calcium deficiency on the 86Rb+ efflux rate appeared to be additive. It is concluded that the effect of furosemide on 86Rb+ efflux is not secondary to reduced calcium uptake and that the effects of furosemide and calcium deficiency are mediated by different mechanisms. The effect of furosemide is compatible with inhibition of loop diuretic-sensitive co-transport of Na+, K+ and Cl- and the effect of calcium deficiency with reduced activity of calcium-regulated potassium channels.     

Possible effects of membrane polarization on calcium uptake by and release from sarcoplasmic reticulum vesicles

Rates of calcium uptake by and calcium release from sarcoplasmic reticulum vesicles isolated from skeletal muscle of the crab seem to depend on membrane potential generated by potassium (K) and chloride (Cl) gradients. This does not appear to be due to an effect of the ions themselves since media of different ionic compositions leading to the same membrane potential, also lead to the same ATP hydrolysis and the same Ca uptake by SR vesicles. From a large positive intravesicular potential (conditions termed "normal" in this paper), membrane depolarization of passively Ca loaded vesicles, produced by changes in K and Cl concentrations in the media, resulted in: i) decrease in rate of calcium uptake; ii) decrease in calcium loading; iii) increase in rate of calcium release despite a decrease in the driving force for calcium ions. Moreover, the addition of caffeine (5 mmol/l) to the different polarization media resulted in a increase in calcium release.     

Perturbed Synaptosomal Calcium Homeostasis and Behavioral Deficits Following Carbofuran Exposure: Neuroprotection by <Emphasis Type="Italic">N</Emphasis>-Acetylcysteine

The protective effects of N-acetylcysteine (NAC) on carbofuran-induced alterations in calcium homeostasis and neurobehavioral functions were investigated in rats. Rats were exposed to carbofuran at a dose of 1 mg/kg body weight, orally for a period of 28 days. A significant decrease in Ca²⁺ATPase activity was observed following carbofuran exposure with a concomitant increase in K⁺-induced ⁴⁵Ca²⁺ uptake through voltage operated calcium channels. This was accompanied with a marked accumulation of intracellular free calcium in synaptosomes. The increase in intracellular calcium levels were associated with an increased lipid peroxidation and decreased glutathione content in carbofuran exposed animals. NAC administration (200 mg/kg body weight, orally) to the carbofuran exposed animals had a beneficial effect on carbofuran-induced alterations in calcium homeostasis and resulted in repletion in glutathione levels and resulted in lowering the extent of lipid peroxidation. Marked impairment in the motor functions were seen following carbofuran exposure, which were evident by the significant decrease in the locomotor activity and reduction in the retention time of the rats on rotating rods. Cognitive deficits were also seen as indicated by the significant decrease in active and passive avoidance response. NAC treatment, on the other hand, protected the animals against carbofuran-induced neurobehavioral deficits. The results support the hypothesis that carbofuran exerts its toxic effects by disrupting calcium homeostasis, which may have serious consequences on neuronal functioning, and clearly show the potential beneficial effects of N-acetylcysteine on carbofuran induced alterations in synaptosomal calcium homeostasis.     

The seasonal breeding hamster as a model to study structure-function relationships in the testis

The present study was undertaken to document morphological changes in the testis of the seasonally breeding golden hamster, an animal model which has been studied extensively from an endocrine standpoint but for which morphological data is inadequate. Germ cells, Sertoli cells and Leydig cells were studied during active and regressed state of gonadal activity by exposing the animals to long (16L:8D) and short photoperiods (6L:18D), respectively. Testis of the hamster exposed to short photoperiods displayed more than a ten-fold reduction in weight and decreased seminiferous tubule diameter. The seminiferous tubules contained primarily Sertoli cell and spermatogonia but also occasional spermatocytes and round spermatids. Leydig cells were decreased in size, a change which appeared to be primarily due to a decrease in cytoplasmic volume. The Leydig cell endoplasmic reticulum which was atypically saccular displayed both rough and smooth components and was decreased during short photoperiods. Mitochondria generally appeared larger and showed considerable structural heterogeneity. Short photoperiod-induced changes in the Sertoli cells included a marked reduction in cell height and an apparent reduction in cell volume, absence of lateral processes, presence of small, almost spheroidal nuclei with inconspicuous nucleoli, an increase in the amount of lipid and decreases in the amount of smooth endoplasmic reticulum and glycogen. The striking differences in the testicular structure between the active and regressed state of gonadal activity follows photoperiod-induced changes in endocrine parameters and suggests that the hamster would be an ideal model to study structure-function relationships in the testis, and especially those related to the Sertoli cell.     

Age-related changes in activity of cerebellum Purkinje cells,shape of the complex spike,and locomotion of Wistar rats under effect of ethanol

The work deals with study of peculiarities of effect of ethanol upon the Purkinje cell activity, shape of the complex spike, and locomotion of rats at different stages of ontogenesis, such as the stage of the morphofunctional maturation of the cerebellar cortex, the mature stage, and in the process of aging. The experiments were carried out on three age groups of Wistar rats: rat pups (2 weeks), adult rats (3–6 months), and senile animals (22–26 months). The administration of ethanol has been established to produce an increase in frequency of simple spikes, a decrease in frequency of complex spikes, a shortening of duration of depression of simple spikes, a decrease in the total duration of the complex spike, the number and frequency of its impulses as well as reduction of the motor activity of animals of all age groups. The change of the majority of the studied parameters occurred by the common temporal scheme. The earliest responding were the rat pups, later-the adult rats, and the last-the animals of the senior group. The stronger effect of ethanol was observed in adult rats. Their differences of all studied parameters, as compared with rat pups and senile animals, were characterized on the whole by the longer period of time and by the higher percent of changes relative to the initial values. Analysis of the obtained results has shown that the most pronounced changes in parameters of the cerebellum Purkinje cell activity and of the complex spike shape corresponded to the more significant decrease in the locomotion level, i.e., were recorded in adult rats. Thus, the work has demonstrated different sensitivity to administration of ethanol in the Wistar rats at different stages of ontogenetic development.