title: Glucose turnover, tolerance and insulin response in wethers, ewes and pregnant ewes in the fed and fasted state.
abstract: Glucose turnover parameters were obtained in fed and fasted wethers, ewes and pregnant ewes in their 2nd and 3rd trimesters, using a jugular bolus injection of D-glucose-2-3H. Fasting significantly (P less than 0,05) reduced glucose turnover (c. 40%) in both the wether and the non-pregnant ewe. A somewhat larger difference (c. 54%) between the fed and fasted ewes was found in their 3rd trimester of pregnancy due to an increase when fed (c. 29% higher turnover than in the non-pregnant ewe) rather than a decrease when fasted, since there was no statistical difference (P less than 0,1) between glucose turnover values of pregnant or non-pregnant fasted ewes. Glucose tolerance was estimated from an intrajugular glucose load (1 g/kg0,75 body mass) in these 3 groups of sheep under both fed and fasted conditions, and the resulting insulin response was followed for 4 hr after the injection. Fasting reduced the plasma clearance rate of glucose by c. 63% in both the wether and the non-pregnant ewe while the reduction was somewhat smaller (c. 51%) during the 2nd trimester of pregnancy. Only the pregnant ewe group showed a corresponding reduction in the resulting insulin response of 46% which was similar in magnitude to the diminished clearance, indicating that factors other than insulin are responsible for the reduced glucose clearance associated with fasting in the wether and non-pregnant ewe. Despite similar baseline plasma glucose values the glucose load appeared to distribute in a space that was significantly less than that found in all 3 groups of fed sheep when trace amounts were injected.
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D005215:Fasting; D005260:Female; D005943:Gluconeogenesis; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D007328:Insulin / Q000097:blood / Q000502:physiology*; D008297:Male; D011247:Pregnancy; D012756:Sheep / Q000378:metabolism*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005947:Glucose