Studies of the protein and the energy metabolism in man during a wintering in Antarctica

Abstract

During the 29th Soviet Antarctic Expedition in Novolazarevskaya from March 1984 to March 1985, the protein and energy metabolisms were studied in six expeditioners from the German Democratic Republic. The investigations were carried out at the beginning of the expedition (May), during the polar night (July) and during the polar day (December). The effect of a special stress situation (sledge trek in April 1984) was investigated in one subject. The stable nitrogen isotope (15)N was used to study the protein metabolism. The assessment of the energy metabolism was based on the oxygen consumption, which was determined by means of a spirograph. In addition, the vital capacity, the breath minute volume, the blood pressure, etc. were measured. The following results were obtained: During the polar night, the utilisation of the dietary proteins and the whole body protein synthesis calculated by means of the (15)N excretion of the total nitrogen in urine were greater (73.6±0.9 % and 3.48±0.17 g protein d(-1) kg(-1), n=3) than the respective values during the polar day (69.7±1.2, p<0.05, n=3 and 3.05±0.07, p<0.05, n=3) and at the beginning of the expedition (69.6±1.4, p<0.02, n=5 and 2.81±0.09, p<0.01, n=5). The lowest values (58.0 % and 2.43 g protein d(-1) kg(-1)) were obtained in the subject after the trek. The resting metabolic rate (in kJ d(-1) m(-2)) was decreased during the polar night (45.6±5.0, n=4) in comparison with the polar day (61.5±11.3, n=3) and the beginning of the expedition (52.3±9.6, n=4) with p<0.01 in both cases.

Seasonal variation in basal metabolic rates among the yakut (Sakha) of Northeastern Siberia

“…Other studies of seasonal changes in metabolic rates in high latitude environments have been conducted among military and scientific personnel stationed in Antarctic bases (Duncan, ; Junghans et al, ; Lewis et al, ; Reed et al, ; Wilson, ) or among urban populations living in northern cities in Europe (Haggarty et al, ; Plasqui et al, ) and Asia (Kashiwazaki, ; Osiba, ). This research provides an inconsistent picture of the impact of seasonal changes in temperature on metabolic rates, with some studies showing significant winter‐time increases in metabolic rate (Kashiwazaki, ; Osiba, ; Plasqui et al, ; Reed et al, ), while others have shown the opposite trend (Duncan, ; Junghans et al, ; Wilson, ), or no significant seasonal effect (Haggarty et al, ; Lewis et al, ; Park et al, ). Some of the differences in seasonal patterns of metabolic rates among high latitude groups likely reflect variation in the severity of climate and differences in activity patterns and cold exposure during the winter months.…”

Tracer kinetics and metabolic models in medicine

“…During wintering in Antarctica, the protein and energy metabolism were studied in six expeditioners [41]. The investigations were carried out at the beginning of the expedition, during the two and a half month polar night and during the polar day.…”

“…Concerning the N and protein metabolism studied by single [16,20,21,24,28,30,33,35,36,40,41,43,44] or multiple pulse [5,29], infusion [31,32,34] and priming [13,42] tracer techniques, we have investigated various metabolic states:…”

“…In many cases, graphic methods using 'plateau', 'slope', 'area' values of the 15 N data have proved to be sufficient for routine evaluations, e.g. [13,16,20,21,[26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44].…”

“…• the metabolism in healthy man [5,41], • the pathological metabolism [19,20,33] • the metabolism at different levels of N supply [30].…”