Glucagon, insulin, and growth hormone in the regulation of metabolism in dairy cows during lactation and ketosis

Two experiments utilizing Holstein cows (second or later lactations) were conducted to better understand hormonal regulation of carbohydrate, lipid, and protein metabolism in early postpartum cows with special emphasis on ketotic cows. Blood was sampled hourly for 24 hours in the first experiment and for 12 hours in the second experiment, at 2 weeks prepartum, at 3 weeks postpartum, during a feed-restriction (50%) induced ketonemia (at approximately 6 weeks postpartum), and after a 4 week recovery period. Cows were fed alfalfa hay prepartum, and a complete mixed diet postpartum.;Onset of lactation in the first experiment and feed restriction to induce ketonemia in both experiments caused mean plasma concentrations of acetoacetate, beta-hydroxybutyrate, free fatty acids (FFA), and growth hormone (GH) to increase and glucose and insulin to decrease. Concentrations of total amino acids (TAA) and glucagon were increased at 3 weeks postpartum and were decreased to equal prepartum concentrations during the ketonemic period in the first experiment. Glucagon concentration tended to be decreased in the ketonemic period during the second experiment. Resumption of ad libitum feeding caused most metabolites and hormones to return to prepartum concentrations. Feeding responses were most evident for FFA, TAA, and GH, and were most dramatic during the ketonemic and early lactation periods. FFA and TAA concentrations decreased after feeding, whereas GH concentration increased after feeding. The metabolite and hormone changes from period to period and after feeding within periods represent adaptations of cows to provide energy and protein substrates to sustain life and milk production.;Bovine glucagon (520 (+OR-) 20 ug) was injected into each cow during each period in the second experiment to measure parameters of glucagon kinetics. Distribution space, turnover rate, and metabolic clearance rate were not different between periods. Pre-injection glucagon concentration was significantly decreased in cows during the ketonemic period. Secretion rate of glucagon was decreased (P \u3c .10) in ketonemic cows. Injection of glucagon caused equal incremental increases of glucose, FFA, and insulin concentrations in all periods. Ketonemic cows seem to have equal gluconeogenic capacity as normal cows when stimulated with exogenous glucagon, therefore lactation ketosis may be caused by decreased secretion of glucagon

Connecting the Vehicle with the Environment - Trends and Challenges

Innovations in automotive electronics have become increasingly complex, resulting in high-end vehicles containing more than 70 electronic control units and offering a variety of functions to the driver. In-vehicle telematics and infotainment systems provide services like digital radio, broadcast services, television, and MP3 audio. Future applications and services will integrate information sources available outside and inside the car, requiring vehicle systems connected with in-vehicle Consumer Electronics devices and the outside world. In order to realized the vision of an intelligent networked car, connected with the environment and providing the driver with information according to his demands, common efforts towards car manufacturer and supplier spanning standards for data exchange are required. The paper discusses possible approaches and future challenges

Possible lack of full cross-resistance of 5HT3 antagonists; a pilot study

We investigated the potential of cross-over to the serotonin receptor (5HT3) antagonist ondansetron after protection failure with tropisetron. Several cases of complete protection were observed. These limited data suggest that there is an indication for retreatment with a different 5HT3 antagonist after an initial failure to another and also stress the need and relevance for comparative studies between 5HT3 antagonists