Diet-induced changes in brain structure and behavior in old gerbils.

BACKGROUND/OBJECTIVES: Aging is associated with many physiological alterations such as changes in metabolism, food intake and brain dysfunction. Possible ways to correct age-related brain dysfunction using dietary treatments still remains undeveloped. The aim of our research was to investigate whether long-term dietary treatment with 2-oxoglutarate (2-OX), which is involved in many regulatory pathways, together with pancreatic-like enzymes of microbial origin (PLEM), which ensure appropriate digestion and absorption of nutrients, affects age-related changes in the brain morphology and cognitive function in old Mongolian gerbils. MATERIALS/METHODS: Experiment was comprised of two separate studies. Samples of the hippocampus were obtained from male Mongolian gerbils of different ages (n=63 in the first study, n=74 in the second study). Immunohistochemistry was used for visualization of the nestin/NeuN-positive neuronal progenitors. Changes in amount of neural cell adhesion molecules (NCAMs) were estimated using enzyme-linked immunosorbent assay. For assessment of cognitive and sensorimotor functions, the T-maze spontaneous alternation test and the adhesive removal test (ART) were used. The ultrastructure of the CA1 hippocampal area was visualized using transmission electron microscopy. RESULTS: Long-term treatment with 2-OX+PLEM led to a significantly increased amount of nestin/NeuN-positive cells in the CA1 hippocampal area and positive changes in learning and sensorimotor functions. As for synaptic transmission, changes in the spatial distribution of synaptic vesicles, as well as the redistribution of NCAM forms, were observed in the hippocampal synapses of the old gerbils. CONCLUSIONS: Taken together, our data show that dietary supplementation with 2-OX+PLEM not only enhances the proliferation and differentiation of neuronal progenitors, but also improves age-related deficits in the morphological and functional state of the brain of old gerbils. Thus, suggesting that a 2-OX+PLEM-enriched diet could also improve brain functions that have deteriorated with age.

Effect of feeding colostrum versus exogenous immunoglobulin G on gastrointestinal structure and enteric nervous system in newborn pigs.

Colostrum is an indispensable source of antibodies (IgG) protecting the newborn pig against infection. We studied the effect of feeding colostrum and purified IgG on early structure and development of the gastrointestinal tract (GIT). Newborn littermate pigs were fed either colostrum, an elemental diet (ED), or an ED supplemented with purified serum IgG (ED + IgG) for 24 h or then only ED up to 72 h. Afterwards, pigs were slaughtered. Colostrum-fed pigs or ED supplemented with IgG (ED + IgG) increased thickness (P < 0.001) of stomach mucosa and muscularis (P < 0.05) compared to the ED group not receiving IgG. Feeding an ED supplemented with IgG improved morphology of the GIT towards that of colostrum-fed piglets and indicates a beneficial effect of IgG on GIT development in neonatal pigs. Immunohistochemical studies indicate that ED feeding may influence the expression of nitric oxide synthase in jejunal myenteric (but not submucous) neurons of newborn pigs.

Exogenous pancreatic-like enzymes are recovered in the gut and improve growth of exocrine pancreatic insufficient pigs.

The exocrine pancreatic insufficient (EPI) pigs grow less due to different disturbances in feed digestion, absorption, and retention. Use of pancreatic-like enzymes of microbial origin in pigs may improve feed use and performance in slow-growing pigs. The aim was to study gut recovery and effectiveness of pancreatic-like enzymes of microbial origin supplementation on pig performance. Six male pigs 10 to 12 kg BW underwent pancreatic duct ligation surgery to induce total exocrine pancreatic insufficiency (EPI). Three cannulas to access the gastrointestinal tract content were installed in stomach, duodenum, and ileum in EPI pigs and in 3 control (healthy) pigs. One month after surgery, enzymes were given before feeding and digesta samples were collected for analyses. The BW of EPI pigs did not increase during 1 mo following surgery (11.7 vs. 11.6 kg BW); however, BW increased after 1 wk of enzyme supplementation (12.1 kg BW). Coefficient of fat and N absorption increased (P < 0.05) in EPI pigs after enzyme supplementation. Activity of amylase, lipase, and protease in chyme samples of EPI pigs was very low compared to controls. In EPI pigs after enzyme supplementation, amylase activity increased from 5.32 to 72.9 units/mL but remained lower than that of healthy pigs (162.7 units/mL). Lipase activity increased from 79.1 to 421.6 units/mL, which was similar to that of controls (507.3 units/mL). Proteolytic activity increased from 7.8 to 69.7 units/mL but still did not reach control pigs (164.3 units/mL). In conclusion, exogenous microbial enzymes mimic endogenous pancreatic enzymes being recovered along the lumen of the gastrointestinal tract. These enzymes might be a useful tool to stimulate growth of slower-growing pigs after the weaning period.

Behavioral changes in response to feeding pancreatic-like enzymes to exocrine pancreatic insufficiency pigs.

Behavioral changes during pancreatic enzyme therapy have never been studied. The present study investigated behavioral changes in exocrine pancreatic insufficiency (EPI) pigs when their feed was supplemented with pancreatic-like enzymes of microbial origin. A crossover design study was used to test the effect of enzyme supplementation in 2 × 4 EPI pigs that underwent pancreatic duct ligation (PDL). After 40 d of adaptation, the study commenced, comprising 2 control and 2 enzyme feeding periods of 10 d each in sequence. On days 7 and 10 of each experimental period, behavior was monitored for 24 h and feed consumption and BW were recorded. Behavioral observations focused on the pigs' activity-- lying down or passive, or sitting, or standing or active--and were expressed as percentage activity for 24 h. During the adaptation period, BW gain was completely inhibited after PDL whereas for the entire study period, the body weight increased from 10.5 ± 1.1 to 14.0 ± 1.4 kg (P < 0.01). Exocrine pancreatic insufficiency pigs were more active when fed the enzymes (21 vs. 18% per 24 h; P < 0.01). Microbial enzyme supplementation not only improved the growth of the EPI pigs but it also increased their activity. This behavior change contradicts the generally accepted norm that satiety evokes by digestion and subsequent nutrients absorption reduces human or animal motility.

The neuroprotective effect of 2-oxoglutarate in the experimental ischemia of hippocampus.

In this study we investigated the potential neuroprotective effect of 2-oxoglutarate (2-OG) on the hippocampus in the transient vessel occlusion ischemia model in the Mongolian gerbil. The morphological and biochemical studies were performed at 7 days after occlusion of carotid arteries. The acute reduction of NeuN-positive neurons in the CA1 pyramidal layer of the hippocampus was accompanied by increased staining intensity for GFAP-positive astrocytes, indicative of glial reaction. The neuron death in the CA1 area coincided with a strong 2.4 fold decrease in the membrane forms of neuronal cell adhesion molecules and elevated levels of astrocyte-specific proteins (soluble GFAP to 2,6 times; filament GFAP to 1,5 times; calcium-binding protein S-100b to 1,6 times). Treatment with 2-oxoglutarate (2.28 g/l drinking water) for between 7 and 21 days attenuated the neuronal death and reactive astrogliosis in this model of experimental ischemia by 20-50%. Our results suggest that 2-OG may prevent the disturbances of neural cells that usually take place during ischemic pathology.

[Neuroprotective effect of quercetin during experimental brain ischemia].

The neuroprotective action by water-soluble form of quercetin was examined in gerbils after transient forebrain ischemia. The animals were exposed to 7 min of bilateral common carotid artery occlusion. Hippocampal CA 1 area was examined 7 days after ischemia-reperfusion. The average density of CA1 pyramidal neurons and GFAP-positive glial cells were counted in sham operated group, in ischemic group and in the groups treated with water-soluble form of quercetin. It was shown that quercetin revealed protective effect by decreasing of delayed neuronal death and reducing reactive astrogliosis after ischemia-reperfusion.

[Endothelial cells during cultivation (a comparative analysis of methodological approaches)]. / Endotelial'ni klityny za umov kul'tyvuvannia (porivnial'nyi analiz metodychnykh pidkhodiv).

In the paper various methods for isolation and cultivation of endothelial cells are compared on the basis of the own data. The comparative analysis of the methods for isolation of endothelial cells from the vessel explant and by enzymatic treatment of aorta or coronary vessels is carried out. The methodical approaches to obtaining pure culture of endotheliocytes are being analysed.

[The participation of the neurons of the caudal ventrolateral area of the medulla oblongata in the cat in regulating vascular tonus]. / Uchastie neironov kaudal'noi ventrolateral'noi oblasti prodolgovatogo mozga koshki v reguliatsii sosudistogo tonusa.

Inhibition of the separate neuronal groups located in the caudal ventrolateral part of the cat medulla at different depths from the brain surface is followed by the development of unidirectional cardiohemodynamic reactions. Microinjection of 30 nl of 0.1 M solution of glycine in the chemosensitive area "L" at a depth not more than 700 microns is followed by an increase of the arterial pressure to 160-225%, presumably, due to enhancement of the total peripheral vascular resistance, the cardiac output and heart rate change insignificantly. Such direction of hemodynamic changes is due to activation of the neurogenic vascular tone. Data obtained give the possibility to appreciate investigated neuronal groups as tonically active, with an inhibitory influence on sympathetically activation of the vessels. The method of the retrograde axonal transport of HRP was used to determine monosynaptic projections from different neuronal pools of the caudal ventrolateral part of medulla to the subsolitary district of the reticular formation. The data obtained contribute to comprehension of mechanisms of interaction in the dorsal and ventral areas of the medulla participating in the regulation of the vascular tone.

[Structural organisation of CA1 zone in the hippocampus of rats in the experimental brain ischemia]. / Strukturna orhanizatsiia zony CA1 hipokampa shchuriv pry eksperymental'nii ishemiï mozku.

The dynamic of structural and ultrastructural changes of CA1 area of the hippocampus was examined in rats after 10 or 15 min of global ischemia (4 vessels occlusion, 4VO) followed by reperfusion. In the early period of reperfusion (15 min, 2 h), the structural changes in synaptic terminals were observed, without any significant signs of neuronal damage. These changes consisted in (i) the increase of the relative number of perforated and multiple synapses, and (ii) the synaptic vesicles rearrangement. Clear neuronal damage appeared morphologically at 24 h, and then developed for 3-6 days and resulted in the delayed damage and death of the hippocampal neurons.