Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 16

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Male rats of Wistar strain (n = 48) were fed a vitamin A deficient diet for 3 days of adaptation period and then a 10 day experimental period to reduce slightly the body stores of this vitamin. Half of the animals were subjected to physical training and/or oral vitamin A supplementation. Four different doses of supplementation were used – 0, 7.5, 15 and 60 μg/d/rat, which is equivalent to 0, 25, 50 and 200 IU of vitamin A, respectively. Animals from the defined groups ran on a treadmill with a rate of 2.0 m/s for 15 minutes per day for 10 days. After overnight fasting, the rats were sacrificed, and insulin in blood serum and hepatic retinol concentrations were estimated. Daily feed intake and daily body gains were similar in groups of sedentary and physically trained rats. A moderate level of oral vitamin A supplementation (the highest supplemented dose was about 6 x the above recommended NRC level) did not cause any changes in these zootechnical parameters. Oral Vitamin A supplementation resulted in an increase in retinol concentration in the liver (F = 15.2, p < 0.001), but without significant difference between trained and untrained animals. Physical training of rats caused a statistically significant decrease of insulin concentration in blood serum (1.53 ± 0.18 vs. 1.73 ± 0.20). This difference was highly significant (F = 11.1, p < 0.001). Vitamin A supplementation was found not to influence the concentration of this hormone, which is responsible for energy metabolism regulation in the body. Based on estimated parameters, the necessity of vitamin A excessive use in physically trained subjects was not proven.
Growing rats fed for 3 months a low-protein (LP) diet (4.5% of energy from protein), possessed about 29% lower body weight than animals consuming adequate-protein diet (20% energy from protein). The LP diet feeding caused an increase in daily feed intake followed by a decrease in feed conversion efficiency. The enrichment of LP diet with folic acid, vitamin B2 and B() (3 times above the level applied in the control diet) did not have any impact on rats BW and supplementation with these vitamins minimize the effect of LP diet on feed intake. The use of examined vitamins had a tendency to diminish an increase in feed conversion ratio caused by the LP nutrition. This effect was significant when all vitamins were added together. Rats fed the LP diet had higher relative weights of lungs, heart, liver and testis. Vitamins enriching the LP diet were observed to decrease a relative weight of lungs (folic acid, vitamin B6 and vitamin mixture), and liver (vitamin B6 and vitamin mixture). A tendency of increasing relative testis weight was also revealed in rats given the LP diet enriched with vitamins. The lower content of hepatic polyunsaturated fatty acids (FA) and a tendency for monoun- saturated FA content to be higher were found in rats fed the LP diet. The LP diet enrichment with folic acid caused that these changes were more pronounced and statistically significant. Enrichment of LP diet with vitamins tested may cause a partial reverse of changes observed in the hepatic FA composition.
Zbadano wpływ cukrzycy typu 1 indukowanej jednorazowym dootrzewnowym podaniem streptozotocyny na aktywność wykorzystania substratów energetycznych przez komórki krwi - glukozy przez erytrocyty i kwasu palmitynowego przez limfocyty. Wywołany proces chorobowy wpływał w istotnym stopniu na obniżenie pobierania glukozy przez erytrocyty. Nie stwierdzono jednoczesnego kompensacyjnego wzrostu aktywności procesu beta-oksydacji w limfocytach, mogącego wyrównać niedobory energetyczne u osobników z cukrzycą indukowaną podaniem streptozotocyny, ale istotne statystycznie obniżenie aktywności tego procesu.
Zbadano wpływ mikroelementów, chromu oraz selenu na różnych stopniach utlenienia, na aktywność pobierania glukozy i aktywność beta-oksydacji kwasów tłuszczowych. Jony były dodawane in vitro w stężeniach nietoksycznych (5 ppm dla Cr plus 3 oraz 0,5 ppm dla Se plus 4 lub Se minus 2 co odpowiada odpowiednio 63,3 µM dla octanu chromowego i 6,33 µM dla seleninu sodowego lub selenometioniny). Stwierdzono różnice w działaniu jonów selenu na badane procesy. Reakcja układów doświadczalnych była zależna od kombinacji jonów. Stwierdzono stymulujący wpływ jonów chromu (+3) na pobieranie glukozy i aktywność degradacji kwasów tłuszczowych. Jony chromu i selenu jak również ich kombinacje aktywowały pobieranie glukozy, przy czym najsilniejszy efekt obserwowano w układzie Cr plus 3/Se minus 2. W przypadku beta-oksydacji dodatek jonów selenu nie wpływał na aktywność procesu, w przeciwieństwie do jonów chromu. Jony Cr plus 3 były aktywatorami procesu rozkładu kwasów tłuszczowych. Kombinacja jonów chromu i selenu hamowała proces beta-oksydacji, przy czym układ Cr plus 3/Se plus 4 hamował badany proces nieznacznie silniej niż kombinacja Cr plus 3/Se minus 2 (odpowiednio ok. 15% i ok. 10%). Wyjaśnienie tych obserwacji wymaga dalszych badań nad wpływem mikroelementów na procesy energetyczne.
Bovine hyperkeratosis is a polyetiologic disease that is increasingly widespread at high milk yielding dairy farms. Clinical manifestation is characterized by focal skin lesions with distinct borders. A clinical study and observation were carried out on 26 Holstein-Friesian dairy cows. During the initial phase of the condition, the skin of the affected cows was itchy, hence the animals tended to lick the skin lesions, or else rub against surrounding objects, with the resultant formation of single spots of raised coat and skin flaking resembling dandruff. These changes appeared on the posterolateral upper sides of the pelvic limbs and around the vulva. Distinct thickening of the wrinkled skin was observed as a result of excessive growth of the epidermis. The superficial part of the skin on major portions of the lesions was dry, corrugated and covered with numerous scales. The epidermis was dry, thickened and rough, with cracks showing the reddened dermal layer. When touched, the animals reacted as if in pain. The disease generally progressed into a chronic condition. In the studied cases, histopathological examination confirmed hyperkeratosis with widened hair follicle infundibulums filled with keratin, the swelling of sweat glands, epithelial atrophy of sweat glands, infiltration of inflammatory cells between and around blood vessels, and massive expansion of keratinized layers of the epidermis. The content of both calcium and magnesium as well as copper, zinc, iron and manganese in grain, roughage, mineral mixtures and in other feeds met the requirements of dairy cows. Blood biochemistry profiles revealed only slightly lower serum calcium values, while zinc values were within the reference range. However, the zinc concentration in skeletal muscles and in the skin was reduced. The mean serum alkaline phosphatase (ALP) activity in the tested animals was also somewhat decreased. Adverse environmental factors such as direct skin contact with faeces and urine as well as zinc deficiency in the cows’ tissues were significant factors in the formation of skin lesions characteristic for hyperkeratosis.
Rats of control group were fed a standard diet (LSM). One of the diets was supplemented with 1% cholesterol (LSM+CH), another one with 5% freeze-dried apple pulp (APP), and the last one with both, 1% cholesterol and 5% apple pulp. Dietary addition of apple pulp significantly increased calcium concentration in femur bone from 154.2±5.6 (LSM, LSM+CH) to 180.1±4.8 g/kg wet weight (APP, APP+CH), while bone magnesium content was reduced from 3.34±0.14 to 2.70±0.12 g/kg. Dietary cholesterol (1%) had the similar significant effect on the bone content of these macroelements, and decreased bone manganese content. Moreover, rats fed diets with cholesterol (LSM+CH, APP+CH) revealed the higher Ca concentration in kidney and the lower liver Mg content (p<0.05) than in the other groups (LSM, APP). The 5% administration of the freeze-dried apple pulp reduced significantly kidney Mn content. It may be concluded that both dietary factors studied (apple pulp and cholesterol) positively influence calcification of bones but a high level of cholesterol significantly reduces bioavailability and/or storage of the other important macroelement – magnesium.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.