title: The hormonal control of lipid metabolism in sheep

authors: Lewis, Kae Jennifer

abstract: The hormonal control of lipid metabolism was investigated by incubation of ovine adipose tissue slices in the presence of hormones the in vitro. The effects of insulin, catecholamines, growth hormone (GH) and insulin-like growth factors (IGFs) on lipogenesis and lipid mobilization were studied to assess their likely individual contributions to overfatness in vivo.
From the various measurements of lipid metabolism made, the rates of fatty acid accumulation in the tissue during the incubation were calculated. Since most of the fatty acid released by lipolysis appeared to be re-esterified, observation of glycerol data alone may give a false impression of the extent of fatty acid mobilization or the overall energy balance of the tissue. About 60 - 100% of fatty acid released by lipolysis could be recycled within the tissue, a phenomenon which is under hormonal control and is possibly linked with maintenance of non-shivering thermogenesis.
Insulin stimulated the rate of lipogenesis (from acetate) by up to 6-fold, with the average stimulation about 70%, but it failed to affect the rate in tissue from one quarter of the animals tested. Also insulin stimulated the retention of fatty acid by the cell as well as fatty acid recycling, even in tissue in which it was not lipogenic. Thus observation of lipogenesis alone can give a false impression of the lipid-storing effects of a hormone. 
IGFs, when present at high concentrations, were lipogenic. However, because the binding proteins may restrict the activity of IGFs in vivo, low concentrations of IGF were tested and shown to be lipolytic. It is suggested that whereas the high concentrations of IGFs have been thought to act via the insulin receptor, low concentrations may mediate the lipolytic response via the IGF receptor. Similar states of negative energy balance in the tissue were caused by the presence of either IGF I, IGF II or adrenalin in the medium. 
GH sometimes stimulated a transient increase in the rate of lipolysis. It is suggested that GH may stimulate the local release of IGF in vitro which then mediates the observed lipolytic activity. GH was also sometimes observed to be lipogenic over the 6 hour incubation period.
To investigate the effects of a known physiological change in the animal in vivo on the subsequent effects on lipid metabolism in vitro, GH was administered to animals and their adipose tissue was compared with tissue from control animals. The basal rate of lipogenesis and fat accumulation in vitro was depressed in the bGH-dosed animals as was deposition of fat in vivo. The effectiveness of insulin in increasing lipogenesis in vitro was reduced in the bGH-dosed animals although the percentage response was unaffected. Thus the “lipolytic” effects of exogenous GH may in fact be due to a reduction in lipogenesis, caused by possible post-receptor desensitization of the tissue to the lipogenic effects of insulin as well as to the presence of increased IGF in vivo. Thus the physiological state of the animal can have profound and lasting effects on lipid metabolism in vitro.

text: The hormonal control of lipid metabolism in sheep The hormonal control of lipid metabolism was investigated by incubation of ovine adipose tissue slices in the presence of hormones the in vitro. The effects of insulin, catecholamines, growth hormone (GH) and insulin-like growth factors (IGFs) on lipogenesis and lipid mobilization were studied to assess their likely individual contributions to overfatness in vivo.
From the various measurements of lipid metabolism made, the rates of fatty acid accumulation in the tissue during the incubation were calculated. Since most of the fatty acid released by lipolysis appeared to be re-esterified, observation of glycerol data alone may give a false impression of the extent of fatty acid mobilization or the overall energy balance of the tissue. About 60 - 100% of fatty acid released by lipolysis could be recycled within the tissue, a phenomenon which is under hormonal control and is possibly linked with maintenance of non-shivering thermogenesis.
Insulin stimulated the rate of lipogenesis (from acetate) by up to 6-fold, with the average stimulation about 70%, but it failed to affect the rate in tissue from one quarter of the animals tested. Also insulin stimulated the retention of fatty acid by the cell as well as fatty acid recycling, even in tissue in which it was not lipogenic. Thus observation of lipogenesis alone can give a false impression of the lipid-storing effects of a hormone. 
IGFs, when present at high concentrations, were lipogenic. However, because the binding proteins may restrict the activity of IGFs in vivo, low concentrations of IGF were tested and shown to be lipolytic. It is suggested that whereas the high concentrations of IGFs have been thought to act via the insulin receptor, low concentrations may mediate the lipolytic response via the IGF receptor. Similar states of negative energy balance in the tissue were caused by the presence of either IGF I, IGF II or adrenalin in the medium. 
GH sometimes stimulated a transient increase in the rate of lipolysis. It is suggested that GH may stimulate the local release of IGF in vitro which then mediates the observed lipolytic activity. GH was also sometimes observed to be lipogenic over the 6 hour incubation period.
To investigate the effects of a known physiological change in the animal in vivo on the subsequent effects on lipid metabolism in vitro, GH was administered to animals and their adipose tissue was compared with tissue from control animals. The basal rate of lipogenesis and fat accumulation in vitro was depressed in the bGH-dosed animals as was deposition of fat in vivo. The effectiveness of insulin in increasing lipogenesis in vitro was reduced in the bGH-dosed animals although the percentage response was unaffected. Thus the “lipolytic” effects of exogenous GH may in fact be due to a reduction in lipogenesis, caused by possible post-receptor desensitization of the tissue to the lipogenic effects of insulin as well as to the presence of increased IGF in vivo. Thus the physiological state of the animal can have profound and lasting effects on lipid metabolism in vitro.

year: 1987

title: Isolation and structure determination of two new hydrophobic microcystins from Microcystis sp. (CAWBG11)

authors: Puddick, Jonathan

subjects: Microcystis sp. CAWBG11

abstract: Two new hydrophobic microcystins, microcystin-FA (1) and microcystin-WA (2), were isolated from the cyanobacterium Microcystis sp. (CAWBG11). The structures were deduced using one- and two-dimensional nuclear magnetic resonance spectroscopy and tandem mass spectrometry. The absolute stereochemistry of the amino acid residues in 1 and 2 was determined using the Advanced Marfey's method.

text: Isolation and structure determination of two new hydrophobic microcystins from Microcystis sp. (CAWBG11) Two new hydrophobic microcystins, microcystin-FA (1) and microcystin-WA (2), were isolated from the cyanobacterium Microcystis sp. (CAWBG11). The structures were deduced using one- and two-dimensional nuclear magnetic resonance spectroscopy and tandem mass spectrometry. The absolute stereochemistry of the amino acid residues in 1 and 2 was determined using the Advanced Marfey's method.

year: 2013

title: The Māori female - her body, spirituality, sacredness and mana : a space within spaces

authors: August, Wikitoria

subjects: Body image in women

abstract: This thesis is an exploration of bodily rituals, practices and cultural spaces of the female Māori body. Critical social theories and Kaupapa Māori research paradigms are combined to disrupt and challenge hegemonic Western knowledges. Qualitative methods - interviews, focus groups and autobiographical experience - are used to understand bodily practices that pertain to being Māori and female. There are three points to my discussion. I argue first, that the embodied relationship between Māori women and urupā and food gathering spaces rests on notions of Papatūānuku and female reproduction. During menstruation or pregnancy most women are restricted from urupā. Many participants, however, view this tikanga positively and describe it as making them feel special. Second, I examine the ways in which Māori female bodies are colonised and positioned between Western patriarchal and traditional ways of being. Due to various reasons surrounding colonisation, there are gaps in younger generations' Māori knowledge and this has led to tensions about which space to occupy. Finally, I discuss mana and conclude by asserting that the Māori female body has not lost individual mana, despite the efforts of colonisation to take mana away from Māori women. Throughout this research I offer cultural perspectives in order to prompt new ways of thinking about the Māori female body. 

The views expressed in this thesis are not the views of all Māori. Practices, tikanga and knowledges vary between different iwi, hapū and rohe.

text: The Māori female - her body, spirituality, sacredness and mana : a space within spaces This thesis is an exploration of bodily rituals, practices and cultural spaces of the female Māori body. Critical social theories and Kaupapa Māori research paradigms are combined to disrupt and challenge hegemonic Western knowledges. Qualitative methods - interviews, focus groups and autobiographical experience - are used to understand bodily practices that pertain to being Māori and female. There are three points to my discussion. I argue first, that the embodied relationship between Māori women and urupā and food gathering spaces rests on notions of Papatūānuku and female reproduction. During menstruation or pregnancy most women are restricted from urupā. Many participants, however, view this tikanga positively and describe it as making them feel special. Second, I examine the ways in which Māori female bodies are colonised and positioned between Western patriarchal and traditional ways of being. Due to various reasons surrounding colonisation, there are gaps in younger generations' Māori knowledge and this has led to tensions about which space to occupy. Finally, I discuss mana and conclude by asserting that the Māori female body has not lost individual mana, despite the efforts of colonisation to take mana away from Māori women. Throughout this research I offer cultural perspectives in order to prompt new ways of thinking about the Māori female body. 

The views expressed in this thesis are not the views of all Māori. Practices, tikanga and knowledges vary between different iwi, hapū and rohe.

year: 2004