Authors: Sergio Polakof Jesús M Míguez José L Soengas
Publish Date: 2008/07/29
Volume: 194, Issue: 9, Pages: 829-839
Abstract
To evaluate the possible role of glucose in the control of food intake FI in fish and the involvement of glucosensing system in that role we have subjected rainbow trout via intraperitoneal injections to control hyperglycemic 500 mg kg−1 glucose body mass or hypoglycemic 4 mg kg−1 bovine insulin conditions for 10 days The experimental design was appropriate since hypoglycemia and hyperglycemia were observed the first 5 days after treatment and changes observed in metabolic parameters in liver were similar to those of fish literature Hyperglycemic conditions elicited small changes in FI accompanied by increased glucose and glycogen levels glucokinase GK activity and glycolytic potential in hypothalamus and hindbrain In contrast hypoglycemic conditions elicited a marked increase in FI accompanied by decreased glucose and glycogen levels and GK activity in the same brain regions whereas both regions displayed different responses in glycolytic potential These results allow us to hypothesize that despite the relative intolerance to glucose of carnivorous fish changes in plasma glucose levels in rainbow trout detected by glucosensing areas in brain regions hypothalamus and hindbrain are integrated in those or near areas eliciting a response in FI which was more important under hypoglycemic than under hyperglycemic conditionsThis study was supported by research grants from Ministerio de Educación y Ciencia and European Fund for Regional Development AGL200765744C0301/ACU and Universidade de Vigo ContratoPrograma para grupos de investigación consolidados Sergio Polakof was recipient of a predoctoral fellowship from the Xunta de Galicia Program Maria Barbeito
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