- Email: [email protected]
The regulation of food intake, body weight and energy homeostasis
62
Abstracts
membranes in a number of brain areas may have a role as a rapid transducer responding to plasma oestrogen levels and may thereby modulate the activity of central nervous pathways that regulate autonomic function.
systems (e.g., melanocortins) in the hypothalamus, and how they are integrated to maintain energy balance over long intervals. doi:10.1016/j.autneu.2007.06.094
doi:10.1016/j.autneu.2007.06.093
I-4A-01 The regulation of food intake, body weight and energy homeostasis Stephen C. Woods Department of Psychiatry, University of Cincinnati, Cincinnati OH, USA Energy homeostasis is the complex of on-going processes that include maintaining immediately available as well as stored nutrient levels at optimal levels given the environment. To accomplish this, the brain receives continuous information about stored energy (mainly fats in adipose tissue and glycogen in liver) and current and anticipated fluxes in critical organs, as well as about food that is potentially available or being eaten and absorbed. The brain in turn determines when and how much food will be consumed, which fuel depots (i.e., adipose tissue or liver) will be tapped to provide energy needs, and the availability of nutrients to individual tissues as well as the sensitivity of those tissues to utilize the nutrients; the brain also balances all of these activities with other behaviors. This review discusses hormonal and neural signals generated as food is being consumed, and upon adiposity signals related to the amount of fat stored in the body, as well as how these signals influence energy intake and ultimately body weight. It also reviews recent evidence that areas of the brain including the arcuate nucleus of the hypothalamus are responsive to individual nutrients as well as to neural and hormonal signals related to satiation and adiposity, and that these areas control coordinated responses involving the somatic and autonomic nervous systems and the pituitary and other endocrine systems. Hence, this presentation will review current understanding of brain controls over energy intake (food intake) and expenditure (metabolism and exercise). A key concept regards the integration of signals generated acutely in response to food being eaten with signals that reflect the current level of nutrients stored in adipose tissue. Meal-related signals are typified by ghrelin and cholecystokinin, and adiposity signals are typified by leptin and insulin. The underlying principle is that when an individual is underweight, decreased levels of adiposity signals allow larger meals to be consumed, more nutrients to be shunted into adipose tissue and lipids, and consequently fewer calories to be utilized for ongoing activity; and opposite responses occur during states of positive energy balance. Discussion will focus on where and how these signals are translated into efferent responses, with a focus upon the balance between anabolic (e.g., NPY, AgRP) and catabolic
I-4A-02 Olfactory stimulation with grapefruit oil and lavender oil affects autonomic nerves, lipolysis and appetite in the rat Akira Niijima a, Katsuya Nagai b a Niigata University School of Medicine, Niigata, Japan b Y.M.P.-International Corporation, ANBAS Business Unit, Japan Report deals with effects of olfactory stimulation with grapefruit oil (SGFO)and lavender oil (SLVO) on activity of sympathetic nerve innervating white adipose tissue, brown adipose tissue, adrenal medulla and gastric vagus nerve in anesthetized rats. Stimulation with SGFO activated sympathetic nerve activity and inhibited vagal nerve activity to stomach, and elevated plasma glycerol level. Stimulation with SLVO suppressed sympathetic and facilitated vagal nerve, and decreased plasma glycerol level. A 15-min exposure to SGFO three times a week in non-anesthetized rats reduced food intake and body weight, however, same procedure with SLVO resulted in opposite responses. Results indicate that SGF0 activates body function and increase in energy expenditure, and SLVO shows sedative and assimilative effects on body function through modulation of autonomic nerve activity. These results may give physiological bases on aromatherapy. doi:10.1016/j.autneu.2007.06.095
I-4A-03 Disturbed glucose homeostasis in vagotomized rats with taa-hepatitis: An explanation for post liver transplant diabetes Ilse Bockx a, Marcel Zeegers a, Ingrid Vander Elst a, Jos van Pelt a, Frederik Nevens a, Jan Tack b, David Cassiman a a Department of Hepatology, University Hospital Gasthuisberg, Leuven, Belgium b Department of Gastroenterology, University Hospital Gasthuisberg, Leuven, Belgium Background Vagal innervation of the liver is essential for glucose homeostasis. An acute increase of vagal input provokes a storage stimulus, which results in an increase in insulin-
Abstracts
membranes in a number of brain areas may have a role as a rapid transducer responding to plasma oestrogen levels and may thereby modulate the activity of central nervous pathways that regulate autonomic function.
systems (e.g., melanocortins) in the hypothalamus, and how they are integrated to maintain energy balance over long intervals. doi:10.1016/j.autneu.2007.06.094
doi:10.1016/j.autneu.2007.06.093
I-4A-01 The regulation of food intake, body weight and energy homeostasis Stephen C. Woods Department of Psychiatry, University of Cincinnati, Cincinnati OH, USA Energy homeostasis is the complex of on-going processes that include maintaining immediately available as well as stored nutrient levels at optimal levels given the environment. To accomplish this, the brain receives continuous information about stored energy (mainly fats in adipose tissue and glycogen in liver) and current and anticipated fluxes in critical organs, as well as about food that is potentially available or being eaten and absorbed. The brain in turn determines when and how much food will be consumed, which fuel depots (i.e., adipose tissue or liver) will be tapped to provide energy needs, and the availability of nutrients to individual tissues as well as the sensitivity of those tissues to utilize the nutrients; the brain also balances all of these activities with other behaviors. This review discusses hormonal and neural signals generated as food is being consumed, and upon adiposity signals related to the amount of fat stored in the body, as well as how these signals influence energy intake and ultimately body weight. It also reviews recent evidence that areas of the brain including the arcuate nucleus of the hypothalamus are responsive to individual nutrients as well as to neural and hormonal signals related to satiation and adiposity, and that these areas control coordinated responses involving the somatic and autonomic nervous systems and the pituitary and other endocrine systems. Hence, this presentation will review current understanding of brain controls over energy intake (food intake) and expenditure (metabolism and exercise). A key concept regards the integration of signals generated acutely in response to food being eaten with signals that reflect the current level of nutrients stored in adipose tissue. Meal-related signals are typified by ghrelin and cholecystokinin, and adiposity signals are typified by leptin and insulin. The underlying principle is that when an individual is underweight, decreased levels of adiposity signals allow larger meals to be consumed, more nutrients to be shunted into adipose tissue and lipids, and consequently fewer calories to be utilized for ongoing activity; and opposite responses occur during states of positive energy balance. Discussion will focus on where and how these signals are translated into efferent responses, with a focus upon the balance between anabolic (e.g., NPY, AgRP) and catabolic
I-4A-02 Olfactory stimulation with grapefruit oil and lavender oil affects autonomic nerves, lipolysis and appetite in the rat Akira Niijima a, Katsuya Nagai b a Niigata University School of Medicine, Niigata, Japan b Y.M.P.-International Corporation, ANBAS Business Unit, Japan Report deals with effects of olfactory stimulation with grapefruit oil (SGFO)and lavender oil (SLVO) on activity of sympathetic nerve innervating white adipose tissue, brown adipose tissue, adrenal medulla and gastric vagus nerve in anesthetized rats. Stimulation with SGFO activated sympathetic nerve activity and inhibited vagal nerve activity to stomach, and elevated plasma glycerol level. Stimulation with SLVO suppressed sympathetic and facilitated vagal nerve, and decreased plasma glycerol level. A 15-min exposure to SGFO three times a week in non-anesthetized rats reduced food intake and body weight, however, same procedure with SLVO resulted in opposite responses. Results indicate that SGF0 activates body function and increase in energy expenditure, and SLVO shows sedative and assimilative effects on body function through modulation of autonomic nerve activity. These results may give physiological bases on aromatherapy. doi:10.1016/j.autneu.2007.06.095
I-4A-03 Disturbed glucose homeostasis in vagotomized rats with taa-hepatitis: An explanation for post liver transplant diabetes Ilse Bockx a, Marcel Zeegers a, Ingrid Vander Elst a, Jos van Pelt a, Frederik Nevens a, Jan Tack b, David Cassiman a a Department of Hepatology, University Hospital Gasthuisberg, Leuven, Belgium b Department of Gastroenterology, University Hospital Gasthuisberg, Leuven, Belgium Background Vagal innervation of the liver is essential for glucose homeostasis. An acute increase of vagal input provokes a storage stimulus, which results in an increase in insulin-