Appetite regulation and energy balance
The group focuses on appetite regulation and energy balance in particular the influence of palatable food on these parameters. Appetite regulation is a homeostatic system that through hunger and satiety signals regulates energy balance and body weight. Basically appetite regulation is asymmetric in that hunger signals are stronger than satiety signals. This means that the body strongly defends itself against starvation whereas overfeeding leads to weak satiety signalling, hence promoting overweight and obesity.
Appetite regulation is assymetric
- Hunger > Satiety
- The brain drives the hunger
- The body signals satiety
With palatable food, i.e. food containing fat and sugar the appetite control is even more difficult, since there is now an involvement of the reward system. The reward system tells the body to eat more and to eat more of the same nutrient that was recently eaten, hence promoting overeating in a narrow way.
The project increases the knowledge of appetite regulation with palatable food and also aims at finding mechanisms and targets to control feeding behaivour with palatable food to achieve energy balance.
Regulation of fat intake - role of enterostatin
Collaborators: Mark Lowe, Pittsburgh, USA, David York, Utah, USA
Enterostatin is a pentapeptide that is produced though tryptic cleavage of pancreatic procolipase in the intestine during fat digestion. The peptide was discovered by our group and its mechanism of action has been described. In short enterostatin was found to decrease food intake and decrease body weight in mouse and rat in particular when these were fed high-fat diet. At the same time insulin secretion was decreased.
The receptor for enterostatin was found to be the beta subunit of theF1F0-ATPsynthase.
The present investigations aim at characterising the enterostatin knockout mouse as regards food intake, body weight and metabolic parameters.
Control of appetite and body weight – the use of green leave components
Collaborators: Mona Landin-Olsson, Malin Olbe, Gösta Lilius, Per-Åke Albertsson, Sinan Emek, Hans-Erik Åkerlund, Jens H. Rehfeld, Marilyn Rayner, Ingegerd Sjöholm, Per-Olof Hegg
The group has a long interest to be able to induce appetite control. The aim has been to strengthen and induce the body to produce stronger satiety signals and weaker hunger signals. After several trials we have now identified components from green leaves that can be successfully used to control appetite even with palatable food.
The components are called thylakoids and work through covering the lipid droplets during intestinal fat digestion, thereby hindering the pancreatic lipase and its protein cofactor colipase to reach its substrate.
Present experiments aim at investigating the effect of the green leave components in man during long-term treatment, in obese subjects. Another aim is to find a proper way of administering the thylakoids. At present time we run experiments with the thylakoids in juice as well as in pie.
The influence of palatable food on neurogenesis of hippocampus
Collaborators: Patrik Brundin, Andreas Lindqvist, Nathanael Göransson
Previous work has demonstrated a decreased hippocampal neugenesis by high fat diet in male rat. The fat was saturated as well as corn oil. Our present studies concern the influence of sweet tasting food, containing, glucose, fructose as well as sucrose. Hippocampal neurogenesis is investigated as well as inflammatory markers. Preliminary studies indicate a decreased neurogenesis by fructose and sucrose as well as an increased inflammatory response.
The intestinal uptake of nutrients and regulation of pancreatic secretion
Collaborators: Björn Weström, Stefan Pierzynovsky
The regulation of pancreatic secretion by various nutrients is a long-standing interest of our group. The studies are carried out in rat and pig. Also the intestinal uptake of nutrients using intestinal segments and Ussing chambers. The influence of green plant thylakoids are being investigated.
Studies of obese subjects
Collaborators: Mona Landin-Olsson,
Obesity is increasing globally. The time scale suggests that palatable food (sugar drinks, pommes frites) may be responsible for such a rapid rise. Regulation of food intake and the influence of various diets is studied in obese subjects in collaboration with professor Mona Landin-Olsson. The obese subjects are recruited from the Obesity Unit headed by Mona Landin-Olsson. The patients are given a standard breakfast and hunger and satiety hormones measured. After treatment with various diets (plate model, pulver diets and green leave components) the same breakfast is eaten and hunger satiety hormones measured. In addition blood lipids and glucose/insulin homeostasis is measured. Sofia meets the patient every week and the blood sampling is taking place at the beginning and in the end of the experiments.
Obesity in pre-school children is also studied together with Dr Kristina Järnek-Thorngren, Pediatric Clinic, Lund University Hospital.
Health of women –myths and facts
Collaborators: Gunilla Jarlbro, Inger Lövcrona, Tiina Rosenberg
Health of women is studied in a trans-faculty network, where both medical and humanistic views are intermixed. This group has regular meetings and are responsible for 8th March Conference each year, with titles such as Women health – facts and myths. We have written a text book with the following title:
Women health – facts and myths
Gunilla Jarlbro and Charlotte Erlanson-Albertsson (eds)
Studentlitteratur (2009). In press.