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Effect of intracerebroventricular (i.c.v.) administration of opioids on food intake in pigs
196
ABSTRACTS
levels known to produce gastric secretion (37.5,75, 150,30Opg/kg), and water intake during the subsequent hour was measured. Pentagastrin did not alter water intake.
Oxitocin Inhibits Food and Fluid intake. R. ARLETTI, A. BENELLI A. BE RTO LI N I. Institute of Pharmacology, University of Modena, Italy.
and
Increasing evidence indicates that oxitocin (OT) has neuromodulatory effects on different CNS activities. The paraventricular nucleus of the hypothalamus, which is a major source of OT, is involved in feeding behaviour. Here we present evidence that OT inhibits food and fluid intake, in rats, either after intraperitoneal (ip.) or intracerebroventricular (i.c.v.) administration. Feeding inhibition was dose-dependent both in normally-fed and in fasting rats, and was antagonized by the OT antagonist d(CH,),Tyr(Me)-[Ornlavasotocin. Drinking inhibition was dose-dependent both in normally-drinking rats and in three different models of thirst-induction (waterdeprivation, NaCl, A II).
Role of Central
Cholinergic
Mice. G. AYAD, M. ZOUAMBIA
Parameters
in Hydromineral
Homeostasis
in
and A. EBEL. Inst. Sci. Nat., U.S.T.H.B., Algiers, Algeria and Cent. Neurochem., C. N. R.S., Strasbourg, France.
For up to 6 days progressive water deprivation (WD) was used as a natural thirst stimulus in NMRI mice. A very significant increase in choline acetyl transferase (ChAT) was observed at the hypothalamic level after 4 and 6 days WD. On the other hand, a net decrease of ChAT was observed at the level of(i) the hippocampus after 6 days WD; (ii) the fronto-parietal cortex after 4 and 6 days WD. A decrease in sodium dependent high affinity choline uptake (SDHACU) in the hypothalamus after 2 days WD, and in the hippocampus after 2 and 4 days WD. In the hippocampus a significant increase of muscarinic receptor binding sites was noted after 2 days WD.
Preferences Nutritional
Between Side-by-Side Flavours Reinforced by Delayed Differences. B. J. BAKER and D. A. BOOTH. School of Psychology,
University of Birmingham, U.K.
Rats were conditioned by nutrient differences between two diets to prefer the flavour of the richer diet. Such learning occurred with a 10min delay between presentation of both dietary stimuli and intubation of the nutrient mixture proportional to flavour intakes. Thus, rats are able to distinguish between the nutritional aftereffects of two distinctive diets presented concurrently. Also, reinforcement that has been suggested to arise from gastric chemoreception is attributable to delayed postgastric effects.
Effect of lntracerebroventricular Food Intake in Pigs. B.A. BALDWIN,
(i.c.v.)
Administration
of Opioids
on
C. DELA RlVAand I. EBENEZER. AFRClnstitute of Animal Physiology and Genetics Research, Babraham, Cambridge CB2 4A z U.K.
Young pigs, with lateral intracerebroventricular (i.c.v.) cannulae, housed individually in cages with operant panels, could obtain food and water ad libitum. I.c.v. injection of 2OOpg of Dynorphin 1-13 or 1-17 resulted in a significant meal commencing within 2-5 min. Dynorphin l-8 or l-9 were ineffective. Dynorphin 1-13 or l-17, administered before a meal or 20 min after it started, increased meal size when pigs fed after 4 h deprivation. Naloxone i.c.v. abolished the effects of dynorphin. Leumorphin, an opioid related to dynorphin, increased food intake in the ad libitum situation but DAGO (a mu receptor agonist) or DSLET ( a delta agonist) were ineffective. Endogenous dynorphin and leumorphin probably influence food intake in pigs.
ABSTRACTS
levels known to produce gastric secretion (37.5,75, 150,30Opg/kg), and water intake during the subsequent hour was measured. Pentagastrin did not alter water intake.
Oxitocin Inhibits Food and Fluid intake. R. ARLETTI, A. BENELLI A. BE RTO LI N I. Institute of Pharmacology, University of Modena, Italy.
and
Increasing evidence indicates that oxitocin (OT) has neuromodulatory effects on different CNS activities. The paraventricular nucleus of the hypothalamus, which is a major source of OT, is involved in feeding behaviour. Here we present evidence that OT inhibits food and fluid intake, in rats, either after intraperitoneal (ip.) or intracerebroventricular (i.c.v.) administration. Feeding inhibition was dose-dependent both in normally-fed and in fasting rats, and was antagonized by the OT antagonist d(CH,),Tyr(Me)-[Ornlavasotocin. Drinking inhibition was dose-dependent both in normally-drinking rats and in three different models of thirst-induction (waterdeprivation, NaCl, A II).
Role of Central
Cholinergic
Mice. G. AYAD, M. ZOUAMBIA
Parameters
in Hydromineral
Homeostasis
in
and A. EBEL. Inst. Sci. Nat., U.S.T.H.B., Algiers, Algeria and Cent. Neurochem., C. N. R.S., Strasbourg, France.
For up to 6 days progressive water deprivation (WD) was used as a natural thirst stimulus in NMRI mice. A very significant increase in choline acetyl transferase (ChAT) was observed at the hypothalamic level after 4 and 6 days WD. On the other hand, a net decrease of ChAT was observed at the level of(i) the hippocampus after 6 days WD; (ii) the fronto-parietal cortex after 4 and 6 days WD. A decrease in sodium dependent high affinity choline uptake (SDHACU) in the hypothalamus after 2 days WD, and in the hippocampus after 2 and 4 days WD. In the hippocampus a significant increase of muscarinic receptor binding sites was noted after 2 days WD.
Preferences Nutritional
Between Side-by-Side Flavours Reinforced by Delayed Differences. B. J. BAKER and D. A. BOOTH. School of Psychology,
University of Birmingham, U.K.
Rats were conditioned by nutrient differences between two diets to prefer the flavour of the richer diet. Such learning occurred with a 10min delay between presentation of both dietary stimuli and intubation of the nutrient mixture proportional to flavour intakes. Thus, rats are able to distinguish between the nutritional aftereffects of two distinctive diets presented concurrently. Also, reinforcement that has been suggested to arise from gastric chemoreception is attributable to delayed postgastric effects.
Effect of lntracerebroventricular Food Intake in Pigs. B.A. BALDWIN,
(i.c.v.)
Administration
of Opioids
on
C. DELA RlVAand I. EBENEZER. AFRClnstitute of Animal Physiology and Genetics Research, Babraham, Cambridge CB2 4A z U.K.
Young pigs, with lateral intracerebroventricular (i.c.v.) cannulae, housed individually in cages with operant panels, could obtain food and water ad libitum. I.c.v. injection of 2OOpg of Dynorphin 1-13 or 1-17 resulted in a significant meal commencing within 2-5 min. Dynorphin l-8 or l-9 were ineffective. Dynorphin 1-13 or l-17, administered before a meal or 20 min after it started, increased meal size when pigs fed after 4 h deprivation. Naloxone i.c.v. abolished the effects of dynorphin. Leumorphin, an opioid related to dynorphin, increased food intake in the ad libitum situation but DAGO (a mu receptor agonist) or DSLET ( a delta agonist) were ineffective. Endogenous dynorphin and leumorphin probably influence food intake in pigs.