The effects of starvation on the thermogenic parameters of three different mitochondrial subpopulations in brown adipose tissue (BAT) of both post-cafeteria obese and lean rats were investigated. Tissue from different BAT depots from fed and 24 h starved rats were collected, pooled and three mitochondrial subpopulations were isolated by differential centrifugation; the M1 fraction (1000 g), the M3 fraction (3000 g) and the M15 fraction (15,000 g). Thermogenic parameters were measured in the three mitochondrial subtypes, and uncoupling protein (UCP) mRNA was determined in BAT. The results showed that starvation induced a decrease in mitochondrial turnover in BAT from both lean and obese rats. Moreover, a selective net loss of UCP from the lightest mitochondrial fraction (M15) in lean rats, with a concomitant reduction of UCP mRNA was observed. The reductions did not occur in obese rats and, as a result, a change in UCP distribution between the mitochondrial subpopulations was produced, with an increase in the M1 mitochondrial subtype. The lack of response of UCP to starvation observed in BAT of obese rats compared with the decrease seen in lean animals, is a consequence of a different mitochondrial subpopulation composition and/or a different response of a particular subpopulation to starvation.
This article provides a summary of the archaeological context of Bell Beaker pottery from two Ambrona Valley (Soria, Spain) tombs whose chemical analysis identifies the existence of a primitive wheat beer. This is compared with other new analyses in Iberia, from both Neolithic and Copper Age sites, which also demonstrate the use of alcoholic beverages. The two Ambrona examples are Copper Age Bell Beaker intrusions into earlier Middle Neolithic Monumental graves. The archaeological features of both discoveries are described, and an interpretation is offered concerning the social and symbolic context in which these Bell Beaker inhumations were deposited, and the role that alcoholic beverages such as beer might have played in this social context.
The relative stability against a decrease in adrenergic stimulation of the uncoupling protein (UCP) incorporated into different mitochondrial fractions was investigated in brown-fat-cell cultures. Cultures were initiated with undifferentiated cells from young mice and were acutely stimulated with noradrenaline at confluence (day 7). Cells were harvested just after the finish of the 24 h stimulation treatment or 24 h later, and three mitochondrial fractions were isolated by differential centrifugation: the M1 fraction (1000 g), the M3 fraction (3000 g) and the M15 fraction (15,000 g). The results obtained in vitro indicate that removal of adrenergic stimulation determines a selective loss of UCP from the lightest mitochondrial fractions (M3 and M15). Similar results were obtained in a situation in vivo (24 h starvation in mice) which is known to lead to a decreased noradrenaline input to brown adipose tissue, with decreased UCP levels. Thus brown adipocytes possess different mitochondrial subpopulations, which exhibit characteristic changes in their UCP turnover in response to thermogenic signals.
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