Uncoupling proteins (UCPs) are supposed to be involved in diet-induced thermogenesis. Their activities are usually elevated by feeding and reduced by fasting in normal animals. To investigate whether fasting affects the expression of UCPs mRNA in brown adipose tissue (BAT) of bilateral ventromedial hypothalamus (VMH)-lesioned rats, we determined the gene expression of UCP1, UCP2 or UCP3 in BAT of VMH-lesioned rats and examined oxygen consumption in these rats under fed or 48-h fasted conditions. Northern blotting revealed no difference in the expression of UCPs mRNA in BAT between VMH-lesioned and sham-operated rats under the fed condition, however, expressions were increased markedly in BAT of VMH-lesioned rats under the fasted condition. Under the fed condition, no difference in oxygen consumption was observed between VMH-lesioned and sham-operated rats. Under the fasted condition, oxygen consumption decreased in both rats, however, it decreased in VMH-lesioned less than in sham operated rats. To explore the mechanism that fasting elevated BAT UCPs mRNA in VMH-lesioned rats, we measured peroxisome proliferator-activated receptor (PPAR)-gamma mRNA and protein in BAT, because PPAR-gamma agonist can elevate UCPs mRNA levels in BAT. Under the fed condition, no differences in the expression of PPAR-gamma mRNA and protein content were observed between in BAT of VMH-lesioned and sham-operated rats. Under the fasted condition, however, both increased in BAT of VMH-lesioned rats. These results suggest that VMH-lesions enhance the gene expression of UCPs in BAT under long-term fasting as a defensive reaction to inhibit the reduction of body temperature through an increase in PPAR-gamma activity.

Adipose Tissue, Brown↗

PubMed2003

Non-traumatic recurrent dissection and its spontaneous repair in the circle of Willis: report of two autopsy cases.

Post-mortem examinations of the circle of Willis in two cases of subarachnoid hemorrhage disclosed a wide spectrum of vasculopathy ranging from a minimal tear between the intima and media, and between the media and adventitia, to complete transmural disruption leading to the formation of pseudoaneurysms. The presence of coexistence of the focal lesions with complete replacement of the entire arterial wall with thick fibrous connective tissues and the vasculopathy was suggestive of the spontaneous repair of recurrent non-traumatic dissection of intracranial arteries. The patients were 58-year-old and 43-year-old females. There was no history of injury to the head or neck in either case. They were hypertensive, but the degree of atherosclerotic changes in the circle of Willis was compatible with age. There was no histological evidence of vasculitis. The role of hypertension and medial mucoid degeneration in the genesis of non-traumatic dissection of intracranial arteries was discussed.

Adult↗

PubMed2003

Effects of a high-sucrose diet on body weight, plasma triglycerides, and stress tolerance.

We examine the effects of feeding a high-sucrose diet on body weight gain, plasma triglycerides, and stress tolerance in rats. Feeding a high-sucrose (60%) diet for 2 weeks did not induce a greater body weight gain compared with that of standard diet when caloric intake was similar in ventromedial hypothalamic-lesioned obese and sham-operated lean animals. The high-sucrose diet elevated plasma triglycerides by increasing the triglyceride secretion rate and decreasing the fractional catabolic rate in both groups. In response to stress, feeding a high-sucrose diet for one week induced enhanced gene expressions of heat shock proteins (HSP 70 and 27) and suppressed NOx production in the brain, whereas the standard diet did not. Results suggest that feeding a high-sucrose diet does not induce obesity in lean rats or enhance weight gain in obese rats, if caloric intake is appropriate. The diet does elevate plasma triglyerides in lean and obese rats, but it may have the potential to improve stress tolerance.

Animals↗

PubMed2003

[Common disease and dementia].

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Activities of Daily Living↗

PubMed2002

Distinct role of adiposity and insulin resistance in glucose intolerance: studies in ventromedial hypothalamic-lesioned obese rats.

It remains unclear whether adiposity plays an important role in glucose intolerance independently of insulin resistance. We investigated whether adiposity and insulin resistance had distinct roles in glucose intolerance in rats. We examined glucose tolerance and insulin resistance using ventromedial hypothalamic (VMH)-lesioned rats in the dynamic and the static phases of obesity (2 and 14 weeks after lesioning, respectively). Rats were fed either normal chow or a fructose-enriched diet (60% of total calories). The intravenous glucose tolerance test (IVGTT) was performed by bolus injection of glucose solution (1 g/kg) and blood sampling after 0, 5 10, 30, and 60 minutes. Insulin resistance was evaluated from the steady-state plasma glucose (SSPG) value during continuous infusion of glucose, insulin, and somatostatin. SSPG was not increased in VMH-lesioned rats in the dynamic phase of obesity, but increased markedly in the static phase. The area under the glucose curve (glucose AUC) during IVGTT was increased in VMH-lesioned rats in the static phase, but not in the dynamic phase, when compared with their sham-operated counterparts. A fructose-enriched diet for 2 or 14 weeks increased SSPG values to a similar extent in both sham-operated and VMH-lesioned rats without inducing excess adiposity, but glucose intolerance was only developed in the obese rats. The plasma leptin level, an excellent indicator of adiposity, was significantly related to the glucose AUC independently of the insulin level. Insulin resistance or increased adiposity alone is not sufficient to impair glucose tolerance, but increased adiposity plays an important role in the development of glucose intolerance in an insulin-resistant state.

Animals↗

PubMed2002

[Changes of care status before and after the introduction of the long-term care insurance in Japan--results of care status before the long-term care insurance].

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Activities of Daily Living↗