Hypertonic glucose preloads act preabsorptively to decrease intake in rats on postnatal day 18.
To determine if preloads of glucose act preabsorptively or postabsorptively to inhibit intake, 18-day-old rat pups were deprived for 24 h and then provided with sweet milk during a 30-min independent ingestion test. Five minutes before the test, gastric preloads (5% body weight, BW) or intraperitoneal injections (4 ml/kg BW) of isotonic, hypotonic, and hypertonic solutions of glucose or 2-deoxy-D-glucose (2-DG) were administered. There were two major results: First, preloads of 20% glucose decreased intake much more than intraperitoneal injections of 20% glucose. Second, a preload of 20% 2-DG, which decreases, rather than increases glucose utilization, was as effective as a preload of 20% glucose in decreasing intake. These results are consistent with a preabsorptive osmotic mechanism, but not with a postabsorptive metabolic mechanism, for mediating most, if not all, of the inhibition of intake 5 min after preloads of 20% glucose in rats on postnatal day 18 (P18).
Developmental Psychobiology Laboratory, Department of Psychology, Bar Ilan University, Ramat Gan 52900, Israel.
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Weller
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Tsitolovskya
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GP
Smith
D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology; D003847:Deoxyglucose / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D005260:Female; D005950:Glucose Solution, Hypertonic / Q000008:administration & dosage / Q000494:pharmacology*; D007274:Injections, Intraperitoneal; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012528:Satiety Response / Q000187:drug effects
D000963:Antimetabolites; D005950:Glucose Solution, Hypertonic; D003847:Deoxyglucose