Search

Summary Background: The global climate change has numerous negative effects on human and animal health. The Intergovernmental Panel on Climate Change (IPCC) reported that – beside the spatial distribution changes of vector-borne infections – one of the most threatening consequences of global warming on the health is the increased occurrence of heat stressed time periods. To miti gate the influence of heat stress on animal health and production the first step is to get data about the thermal environment of the animals. Objectives: Present work was performed to develop a web based heat stress forecast system supporting the practitioner colleagues by information to ease the negative effects of thermal environment on animal production. Materials and methods: An internet available system was developed to pro duce heat forecast maps for the Carpathian Basin. The risk maps represent the potential heat stress for pigs and dairy cows based on the species specific Tem perature Humidity Indices (THI) and Livestock Weather Safety Index (LWSI) cat egories. The atmospheric parameters needed to calculate These are obtained from the Global Forecast System (GFS) provided by National Oceanic and Atmos pheric Administration (NOAA) of the USA. The original 0.5ºx0.5º spatial resolution of the THIs are smoothed by the method thin plate spline regression. The maps are generated for six-day length period day by day. All calculations and statis tical procedures were coded in R-language. The web site was developed in the Django Framework (www.djangoproject.com). Results and Discussion: The result of the presented development is a web based heat stress forecast system. By its information the system may help the user in the mitigation of the effects of expected heat waves. Further develop ments could be done depending on the feedbacks by the users of the system.

Summary In the present literature review, the authors discuss the central role of the gutdriven incretin hormones, namely GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide 1), as members of the enteroinsular axis, with regard on the pancreatic insulin production. The GIP, produced by K cells of the small intestines after feed intake, stimulates the insulin secretion of β cells mostly by the mediation of cAMP as a second messenger. Further, GLP-1, released from L cells, being presented in both small and large intestines, increases insulin synthesis by affecting insulin gene expression, enhances pancreatic insulin exocytosis and stimulates proliferation as well as differentiation of β cells. In addition, glucagon production of α cells can be inhibited by GLP-1, while GIP is capable to increase pancreatic glucagon secretion. Concerning the incretin effects in further tissues, lipogenesis and proliferation of osteoblasts can be also stimulated by GIP, leading to enhanced lipid storage in adipose tissue and to faster bone formation of growing animals, respectively. The way of incretin action is partly differing in birds from that of mammals, increasing pancreatic insulin release more likely by influencing the somatostatin production of δ cells rather than by direct stimulation of β cells. However, their anorexigenic effect, similarly to mammalian species, was stated in chicken, as well. Based on the available literature data, the authors declare that special emphasis should be taken on the role of incretin hormones in the complex regulation of insulin secretion. Influencing incretin and insulin homeostasis by nutrition or certain drugs can be of special relevance in the treatment of diabetic patients, and, based on insulin’s anabolic action, in improving the growth performance of food-producing animals.

Az inzulin központi szerepet tölt be a szénhidrát-anyagcsere szabályozásában, így az inzulintermelés és -jelpálya sejtszint5 vizsgálata, és azok takarmánykiegészít4kkel való befolyásolása nagy jelent4séggel bír. Egérkísérletek során megállapították, hogy a per os felvett butirát mind az inzulin-felszabadulást serkent4 inkretin hormonokra (GIP, GLP-1), mind a szövetek inzulinérzékenységére hatást gyakorol. A Tanszék korábbi munkája során igazolták, hogy a butirát csirke esetében is befolyásolja az inkretinek és az inzulin termel4dését, habár eltér4 irányban, mint egérben. Jelen diákköri munka keretében nyúlban végeztünk összehasonlító vizsgálatokat az inkretin- és inzulinszekrécióra vonatkozóan, továbbá csirkében kerestük a választ arra, hogy milyen hatást gyakorol a butirát a sejtek inzulinérzékenységére. Vizsgálatainkat pannon fehér nyulakon és Ross-308 fajtájú brojlercsirkéken végeztük. Az állatokat az intenzív növekedés id4szakában szondán keresztül bolusban adott nátriumbutirát oldattal naponta egyszer kezeltünk, 0,25 és 1,25 g/ttkg dózisban. Az els4 kezelést megel4z4en és azt követ4en több alkalommal vért vettünk a nyulaktól, majd meghatároztuk a minták inzulin- és inkretinkoncentrációját. A csirkék esetében mintát vettünk a májból, a subcutan és abdominalis zsírszövetb4l, valamint a m. gastrocnemius-ból, majd azokból szemikvantitatív Western blot módszerrel határoztuk meg az inzulin jelpálya egyes fehérjéinek expresszióját.