Maciej Kamaszewski

The effect of plant protein-based diet supplemented with dipeptide or free amino acids on digestive tract morphology and PepT1 and PepT2 expressions in common carp (Cyprinus carpio L.).

Common carp (Cyprinus carpio) of average body mass 0.07+/-0.02 g were fed three formulated diets: wheat gluten protein-based diet supplemented with Lys-Gly dipeptide (PP), wheat gluten protein-based diet supplemented with free lysine and glycine (AA), and a wheat gluten protein-based control diet without lysine supplementation (CON), frozen zooplankton (Z) (restricted diet), and a commercial starter food Aglo Norse (AN). After 4 weeks of experimental feeding, fish fed AN diet showed the highest body mass and length. Significantly lower mass occurred in groups fed PP, AA, CON, and Z. Fish fed CON diet showed the lowest intestinal folds and the highest number of mucous cells. Fish fed PP diet showed a significantly higher number of gastrin/cholecystokinin (CCK) positive cells. The diameter of lipid vacuoles in hepatocyte cytoplasm of fish fed formulated diets (PP, AA and CON) was significantly higher than in fish fed zooplankton (Z) and the commercial diet (AN). Hepatocytes of fish fed AA and CON showed a higher nucleus proliferation rate than in the other experimental groups. The quantitative analysis of the number of proliferating cell nuclear antigen (PCNA) and caspase-3(rabbit polyclonal antibody CPP-32)-positive cells showed that the highest proliferation rate was accompanied by the high apoptosis in the intestine of fish fed AA and CON. After 4 weeks of experimental feeding the highest relative expression of PepT1 gene was observed in fish fed PP diet, while the lowest expression occurred in fish fed CON. Feeding carp plant protein-based diet supplemented with Lys-Gly dipeptide (PP) had a beneficial influence on fish growth and metabolism in the digestive tract as compared to fish fed control diet without lysine supplementation (CON).

The effect of peptide absorption on PepT1 gene expression and digestive system hormones in rainbow trout (Oncorhynchus mykiss).

The present study evaluates the effect of protein source (dipeptides, free amino acids, and intact protein) on development and growth of Salmonid fish alevin. Specifically, we follow the expression of oligopeptide transporter protein PepT1 in the intestine of rainbow trout (Oncorhynchus mykiss). Fish were fed exogenously one of four diets: three formulated (lysyl-glycine dipeptide supplemented diet - PP, free lysine and glycine supplemented diet - AA, control diet with no lysine - CON) or commercial starter (Aller Futura - AF). Fish increased mean body weight 8 fold with PP- and AA-supplemented diets resulting in significantly higher weight gain than fish fed CON. Statistical analysis revealed a significant increase in relative PepT1 expression of fish fed experimental diets. Immunohistochemical staining with PepT1 antibody showed the presence of the transporter protein in the brush border membrane of the proximal intestinal enterocytes of fish from all experimental groups. Leptin immunoreactivity occurred not only in the gastric glands but also in proximal intestine and pyloric caeca of fish fed PP, AA and AF diets. Leptin immunoreactivity was also observed in hepatocyte cytoplasm and pancreatic acinar cells. Gastrin/CCK immunoreactive cells were present in the proximal intestine and pyloric caeca.

Influence of nanoparticles of platinum on chicken embryo development and brain morphology

Platinum nanoparticles (NP-Pt) are noble metal nanoparticles with unique physiochemical properties that have recently elicited much interest in medical research. However, we still know little about their toxicity and influence on general health. We investigated effects of NP-Pt on the growth and development of the chicken embryo model with emphasis on brain tissue micro- and ultrastructure. The embryos were administered solutions of NP-Pt injected in ovo at concentrations from 1 to 20 μg/ml. The results demonstrate that NP-Pt did not affect the growth and development of the embryos; however, they induced apoptosis and decreased the number of proliferating cells in the brain tissue. These preliminary results indicate that properties of NP-Pt might be utilized in brain cancer therapy, but potential toxic side effects must be elucidated in extensive follow-up research.

Age-related changes in the central nervous system in selected domestic mammals and primates.

Aging is a process which operates at many levels of physiological, genetic and molecular organization and leads inevitably to death. Brain macroscopic changes by MRI investigation during aging were observed in humans and dogs but chimpanzees did not display significant changes. This suggestion led to the statement that brain aging is different in various species. Although human brain changes, e.g. β-amyloid storage, neurofibrillary tangle formation, lipofuscin, are relatively well known, we are still looking for a suitable animal model to study the mechanisms of aging and neurodegenerative diseases. Therefore, this paper presents a comparative analysis of the changes described in the brains of senile dog, horse and gorilla. In addition we present the latest, non-invasive methods that can be applied in the diagnosis of old age in mammals. Our considerations have shown that the best animal model for further studies and observations on aging is the dog.

Cloning two PepT1 cDNA fragments of common carp, Cyprinus carpio (Actinopterygii: Cypriniformes: Cyprinidae).

1 Division of Ichthyobiology and Fisheries, Faculty of Animal Science, Warsaw University of Life Sciences, Warsaw, Poland 2 Division of Molecular Cytogenetics, Faculty of Biotechnology and Animal Science, West Pomeranian University of Technology, Szczecin, Poland 3 Laboratory of General Physiology, Department of Biological and Environmental Sciences and Technologies, University of Salento, via Provinciale LecceMonteroni, Lecce, Italy 4 School of Environment and Natural Resources, Ohio State University, Columbus, Ohio, USA

Effect of copper nanoparticles administered in ovo on the activity of proliferating cells and on the resistance of femoral bones in broiler chickens

ABSTRACT The objective of this study was to evaluate bone resistance after in ovo administration of copper nanoparticles (NanoCu) and to determine the number of cells positive for proliferating cell nuclear antigen (PCNA) in the femoral bones of broiler chickens (n = 12 per group). The study demonstrated that femoral bones from the NanoCu group were characterised by a higher weight and volume and by significantly greater resistance to fractures compared to the Control group. NanoCu promoted the proliferation of PCNA-positive cells in the long bones of chickens. A significantly higher number of PCNA-positive cells in the bones of birds in the NanoCu group compared with the Control group (137 and 122, respectively) indicate a stimulatory effect during embryogenesis. Considering the improvement in bone resistance to fractures and the effect of NanoCu on the number of PCNA-positive cells in femoral bones, NanoCu may be an alternative agent to minimise the ever-present problem of weak bones in broiler chickens.

Development of the Sense Organs in Percid Fishes

Morphology and arrangement of various receptors in Teleostei indicate trophic and environmental preferences of different species. In the Percidae family, the sensory system begins to develop during embryogenesis and evolves over the larval and juvenile stages. The olfactory placodes develop between 26 (Gymnocephalus sp.) and 78 (walleye, Sander vitreus) hours post fertilization (hpf). However, the olfactory epithelium becomes fully developed at the age of about 1 month, as in the pikeperch (Sander lucioperca). During the ontogeny of fish, taste buds develop later than the olfactory system. In pike-perch juveniles, the first taste buds appear 13 days post hatching, primarily in the mouth and the gills, but later on they become visible in other parts of the body. During embryonic development of percids, the eye is the first sense organ to form. Gymnocephalus sp. show well developed eyes already after 26 hpf, while in walleye embryos the optic vesicles are fully formed after 70 hpf. Fish maintain body balance thanks to their inner ear (labyrinth), while the movement and vibration in the surrounding water is detected by canal neuromasts of the lateral line and superficial neuromasts of the skin. In the embryos of different percid species auditory vesicles appear after 26–70 h of development, while the lateral line – after 103 h.

Growth, Survival, and Body Composition of Sunshine Bass after a Feeding and Fasting Experiment

Abstract There is continuous interest in experimental, semipurified diet formulations and in the formulation of practical, inexpensive diets for grow out of sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis). The effects of four diets on growth, survival, and body composition of sunshine bass after a feeding period (51 d) and a subsequent fasting period (14 d) were examined. To our knowledge, no previous sunshine bass feeding experiments have incorporated a fasting period to simulate the handling and acclimation conditions experienced by farmed fish that are stocked into new environments. Diets consisted of a high-nutrient commercial diet, a wheat-gluten-based practical diet, a semipurified diet (meeting standard nutrient requirements), and a frozen natural diet (chironomids). Fish were hand fed three times per day at 4% of body weight. At the end of the fasting period, samples were collected for histological analysis of the liver and posterior intestine. Survival was signi...

β‐Alanine as a factor influencing the content of bioactive dipeptides in muscles of Hubbard Flex chickens

BACKGROUND The aim of this study was to determine the effect of various doses of β-alanine administered in feed mixtures and of heat treatment on changes in the contents of dipeptides anserine and carnosine in meat of fast-growing Hubbard Flex chickens. RESULTS The study demonstrated a significant effect of dietary administration of β-alanine on anserine content in breast muscles and on carnosine content in leg muscles of the chickens. A successive increase in dipeptide content was observed with increasing β-alanine content in the feed mixture. As a result of heat treatment, a significant (P ≤ 0.01) increase was observed in the anserine content of both breast and leg muscles: over twofold higher anserine content was detected in heat-treated muscles compared with raw muscles. The study showed that interesting effects might occur during β-alanine administration to feed mixtures for chickens, especially including increased contents of anserine and carnosine in skeletal muscles of the birds. CONCLUSION Taking into account the well-documented health-promoting effect of histidine dipeptides and possibilities of increasing their contents in the body by supplementation with β-alanine, anserine and carnosine might be considered as potential components of functional foods.