Pavel Výboh

Bio: Pavel Výboh is an academic researcher from Slovak Academy of Sciences. The author has contributed to research in topics: Quail & Dopamine receptor. The author has an hindex of 8, co-authored 14 publications receiving 297 citations.

The effects of feed restriction on plasma biochemistry in growing meat type chickens (Gallus gallus).

Abstract: The effect of feed restriction on plasma hormones (triiodothyronine — T3, thyroxine — T4, and corticosterone), protein, lipid, carbohydrate, and mineral metabolism and activity of plasma enzymes (creatine kinase, alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase) were studied in meat type female chickens (Gallus gallus). Ad libitum fed birds were compared with those subjected to severe and moderate quantitative feed restriction from 16 to 100 days of age. Feed restriction elevated plasma T4 and corticosterone levels and reduced T3. A feed restriction-induced decrease was observed for plasma protein and albumin concentrations, but not for uric acid and creatinine. Total plasma lipids, triacylglycerols, cholesterol, high density lipids, and calcium were lower for the feed restricted chickens, in particular during the latter phase of the experiment. Concentrations of glucose and phosphorus were not altered by feeding treatment. Activity of alkaline phosphatase was significantly increased in restricted chicks from day 58. Significant changes of plasma biochemical parameters induced by severe and moderate quantitative feed restriction illustrate that limiting feed intake poses an intensive stress on meat type chickens during the rapid growth period. However, activities of creatine kinase, aspartate aminotransferase, and alanine aminotransferase were significantly higher in ad libitum fed chickens during this period. This elevation in enzymatic activity may be in response to tissue damage, indicating potential health and welfare problems also in ad libitum fed meat type chickens, resulting from selection for intensive growth.

Post-hatching dynamics of plasma biochemistry in free-living European starlings (Sturnus vulgaris).

Abstract: This is the first study of plasma biochemical parameters in free-living altricial birds during an entire developmental period in a nest, represented by European starling (Sturnus vulgaris). Dynamics of postnatal changes from hatching until close to fledging (days 1 to 15) were registered. Parameters of protein metabolism represented by total proteins, albumin and globulin concentrations increased continuously during the observed developmental period. There were two peaks in uric acid concentration on days 5 and 11. To the contrary, the creatinine content did not change throughout the observed period and increased only on day 15. Creatine kinase activity gradually increased until day 11 and then fell before fledging. Parameters of lipid metabolism (concentration of total lipids, triacylglycerols and nonesterified fatty acids) in plasma increased gradually reaching a plateau between days 8 and 11 and then declined on day 15. The cholesterol concentration pattern was similar to maximum value on day 11, then consecutively decreased. Concentration of glucose increased until day 8 and remained unchanged until fledging. Whereas calcium reached the highest concentration during days 8 and 11, phosphorus peaked earlier on day 5. The activity of alkaline phosphatase was similar to the pattern found in calcium concentration. Presented data showed an increase in both protein and lipid metabolism during the phase of rapid growth. A remarkable decrease in parameters of lipid metabolism before fledging may reflect increased physical activity and changes in nutrition.

Polycyclic aromatic hydrocarbon (PAH) ecotoxicology in marine ecosystems.

Abstract: Low levels of oil and hence polycyclic aromatic hydrocarbons (PAHs) are naturally present in the marine environment, although levels have increased significantly following human extraction and use of oil and gas. Other major anthropogenic sources of PAHs include smelters, the use of fossil fuels in general, and various methods of waste disposal, especially incineration. There are two major sources for PAHs to marine ecosystems in Norway: the inshore smelter industry, and offshore oil and gas production activities. A distinction is generally made between petrogenic (oil-derived) and pyrogenic (combustion-derived) PAHs. Although petrogenic PAHs appear to be bioavailable to a large extent, pyrogenic PAHs are often associated with soot particles and less available for uptake into organisms. There is extensive evidence linking sediment-associated PAHs to induction of phase-I enzymes, development of DNA adducts, and eventually neoplastic lesions in fish. Most studies have focused on high-molecular-weight, carci...

The hypothalamic-pituitary-thyroid (HPT) axis in birds and its role in bird development and reproduction.

Abstract: This article reviews thyroid function and its hypothalamic-pituitary-thyroid (HPT) axis control in birds with emphasis on the similarities and differences in thyroid function compared to mammals and other vertebrate classes. Thyroid hormones are important in metabolism and the thermogenesis required for homeothermy in birds, as in mammals, the other homeothermic class of vertebrates. Thyroid hormones play important roles in development and growth in birds, as is the case for all vertebrate classes. The developmental effects of thyroid hormones in birds are presented in the context of differences in precocial and altricial patterns of development and growth with emphasis on oviparous development. The sections on thyroid hormone actions include discussion of effects on the development of a number of tissue types as well as on seasonal organismal processes and interactions of the thyroid axis with reproduction. The current picture of how environmental chemicals may disrupt avian thyroid function is relatively limited and is presented in the context of the assessment endpoints that have been used to date. These endpoints are categorized as thyroid and HPT axis endpoints versus target organ endpoints. The final section discusses two recommended assay protocols, the avian two-generation toxicity assay and the avian one-generation assay, and whether these protocols can evaluate thyroid disruption in birds.

Dopamine receptors in a songbird brain

Abstract: Dopamine is a key neuromodulatory transmitter in the brain. It acts through dopamine receptors to affect changes in neural activity, gene expression, and behavior. In songbirds, dopamine is released into the striatal song nucleus Area X, and the levels depend on social contexts of undirected and directed singing. This differential release is associated with differential expression of activity-dependent genes, such as egr1 (avian zenk), which in mammalian brain are modulated by dopamine receptors. Here we cloned from zebra finch brain cDNAs of all avian dopamine receptors: the D1 (D1A, D1B, D1D) and D2 (D2, D3, D4) families. Comparative sequence analyses of predicted proteins revealed expected phylogenetic relationships, in which the D1 family exists as single exon and the D2 family exists as spliced exon genes. In both zebra finch and chicken, the D1A, D1B, and D2 receptors were highly expressed in the striatum, the D1D and D3 throughout the pallium and within the mesopallium, respectively, and the D4 mainly in the cerebellum. Furthermore, within the zebra finch, all receptors, except for D4, showed differential expression in song nuclei relative to the surrounding regions and developmentally regulated expression that decreased for most receptors during the sensory acquisition and sensorimotor phases of song learning. Within Area X, half of the cells expressed both D1A and D2 receptors, and a higher proportion of the D1A-only-containing neurons expressed egr1 during undirected but not during directed singing. Our findings are consistent with hypotheses that dopamine receptors may be involved in song development and social context-dependent behaviors. J. Comp. Neurol. 518:741–769, 2010. © 2009 Wiley-Liss, Inc.

Yellow mealworm larvae (Tenebrio molitor, L.) as a possible alternative to soybean meal in broiler diets

Abstract: The aim of the study was to evaluate the feasibility of replacing soybean meal (SBM) with Tenebrio molitor larvae (TML) meal in broiler diets A total of 80 30-d-old male Shaver brown broilers were divided into two groups fed on two isoproteic and isoenergetic diets differing for protein source (SBM vs TML) Up to 62 d of age, body weight and feed intake were recorded weekly and body weight gain, feed conversion ratio (FCR), protein efficiency ratio (PER) and European efficiency factor (EEF) were calculated At 62 d, blood samples were collected from 16 birds/group for evaluation of blood profiles Feed intake was not different between groups considering the entire period of the trial The FCR was more favourable in the TML than SBM group from 46 d of age and in the entire period of the trial (413 vs 362) The PER was higher in the SBM than in the TML group (192 vs 137) while the EEF was higher in broilers fed on the TML diet (1326 vs 1562) Albumin-to-globulin ratio was higher in broilers fed on SBM than in the other group (044 vs 030) aspartate aminotransferase and alanine aminotransferase were higher in TML than SBM (1951 vs 1786 U/l and 8207 vs 4671 U/l, respectively) Uric acid was higher in broilers fed on SBM than TML (540 vs 416 mg/dl) TML did not affect feed intake and growth rate of broilers from 30 to 62 d of age when compared to an isoproteic and isoenergetic SBM diet, but FCR of the TML group was more favourable than that of the SBM group The lowest albumin-to-globulin ratio in broilers fed on TML suggests a higher immune response, probably due to the prebiotic effects of chitin

Repeated sucrose access influences dopamine D2 receptor density in the striatum.

Abstract: A decrease in D2 dopamine receptor subtype (D2R) binding in the striatum has been reported in obese individuals and drug addicts. We examined D2R density in the striatum of food-restricted rats that had contingent access to food with different incentive values. Results showed that animals receiving limited access to 0.3 M sucrose paired 2 h with a chow meal for 7 days had a significantly lower D2R binding in nucleus accumbens shell and dorsolateral striatum compared with animals that had limited access to chow. There was no differential binding, however, in the accumbens core in any of the groups. These findings indicate that feeding conditions and sucrose intake influence D2R density specifically in subregions of the striatum.