摘要:

Two groups of pigs weighing 90 (Expt A) or 80 (Expt B) kg walked on a horizontal moving rubber belt for a distance of 315 m at a speed of 25.6 ± 0.38 and 28.8 ± 0.35 m/min respectively for 10 min in an open-air-circuit respiration unit. From measurements of VO2 and VCO2, heat production and oxidation of carbohydate and fat were calculated 30 min before (I), 10 min during walking (II) and in intervals of 10 min (III, IV) and 30 min (V) after walking. Heat production increased 2-3 times in section II in relation to section I, remained high for 20 min in section III and IV, but reached the basal line in section V. Oxidation of carbohydrate was the main source for heat productio

ISSN:0250-6807    

DOI:10.1159/000177787

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The effect of physical activity on heat production and oxidation of nutritients was measured by means of indirect calorimetry. The experiment included 6 male and 4 female healthy subjects who, during a 24-hour stay in the respiration chambers, performed, in the morning and afternoon, 15 min cycling with the total work of 6,750 kg m. Experiments were repeated twice (3- to 4-week interval) showing no differences between the gas exchange in the morning and afternoon and between first and second experiment. The gas exchange during cycling was about 4 times higher than during basal periods. The identical work of 66.2 kJ by cycling caused on average a heat increment of 309 kJ, yielding the mean energetic efficiency for the performed work of 0.22. The activity caused an increment of 11.5 g oxidized carbohydrate and 2.6 g oxidized fat.

ISSN:0250-6807    

DOI:10.1159/000177788

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

In order to identify the factors affecting apparent absorption of copper and zinc in vegetarian subjects, percent absorption of copper and zinc was estimated during 6 metabolic experiments, each of 2 weeks duration, carried out on 6 healthy young men. They were observed at 3 levels of energy, i.e. 9.2, 10.5 and 12.1 MJ/day. Intakes of zinc were in the range of 20.6-27.1 mg/day and the observed values of apparent absorption (intake-fecal output) were 11.2-20.3%. In case of copper, intakes were 2.7-5.2 mg/day while the apparent absorption was to the tune of 10.6-21.7%. These values of absorption were lower than those of the non-vegetarian diets. Multiple regression analysis of 17 dietary factors suggested that hemicellulose, milk protein, niacin and cereal protein act as significant enhancers in zinc absorption while thiamine, phytate, oxalates, ascorbic acid and phosphorus acted as inhibitors. Copper absorption was enhanced by the dietary levels of riboflavine, cellulose, milk proteins, oxalates and zinc, while phosphorus, niacin, calcium and pulse protein inhibited the absorption of copper.

ISSN:0250-6807    

DOI:10.1159/000177789

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

This is a study of the value of total serum zinc, serum zinc per g of protein, serum zinc-binding capacity and serum zinc-binding capacity per g of protein in 102 pregnant women during childbirth and in the cord blood of their newborn infants. A control group is established by analyzing these parameters in 10 healthy non-pregnant women on the first day of menstruation and on the day of ovulation during two consecutive menstrual cycles. The total serum zinc and serum zinc per g of protein values found were significantly higher in cord blood than in maternal blood, and the binding capacity of zinc and of zinc per g protein were significantly higher in maternal blood. There is a negative correlation between total zinc and binding capacity and total zinc and binding capacity per g protein both in maternal and in cord blood. In the control group, the values of total zinc and zinc per g protein vary from one menstrual cycle to the next and between the different phases of each cycle. Zinc-binding capacity per g protein during ovulation is significantly lower than during menstruation. These results allow us to conclude that the rise of zinc-binding capacity and zinc-binding capacity per g protein in maternal blood during childbirth, and during menstruation in the control group, can be due to the effect of progesterone. The fact that zinc-binding capacity and zinc-binding capacity per g of protein are higher in maternal blood than in cord blood would confirm the existence of mechanisms which tend to increase binding of zinc in the fetus.

ISSN:0250-6807    

DOI:10.1159/000177790

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The effects of various polyunsaturated/saturated (P/S; 0.29-2.74) and n-6/n-3 (0.49-11.21) ratios of dietary fatty acids and of phenobarbital (PB) stimulation on the activity of liver microsomal mixed-function oxidase (MFO) system were studied in rats using a combination of palm oil, safflower oil and fish oil concentrate. When the n-6/n-3 ratio was kept constant (4.6-4.9) without induction by PB, the highest P/S ratio (2.74) tended to increase the basal PB-uninduced MFO activities; while the PB-induced MFO activities were elevated as the dietary P/S ratio increased. This definitely indicates the role of both n-6 and n-3 polyunsaturated fatty acids (PUFAs) in the elevation of MFO activities with and without PB stimulation. Whereas the n-6/n-3 ratio was varied while maintaining a constant P/S ratio (1.3), the PB-induced MFO activities were significantly elevated by decreasing the n-6/n-3 ratio although the MFO activities were not affected without PB stimulation. The MFO activities induced by PB were directly related to the n-3 PUFA content and inversely related to the n-6 PUFA content of the diets with n-6/n-3 ratios less than 4.55. These results obtained herein suggest that there are significant differences in the effects of n-6 and n-3 PUFAs on liver microsomal MFO activities, especially in relation to the induction of MFOs by PB.

ISSN:0250-6807    

DOI:10.1159/000177791

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

This study examined the effects of supplementing patients with cystic fibrosis daily for 4 weeks with 1,500 mg borage oil, containing 330 mg gamma-linolenic acid, on the fatty acid composition of serum phospholipids (PL) and cholesteryl esters (CE). Vital capacity and forced expiratory volume in 1 s were also measured before and after treatment. In serum PL the content of arachidonic acid (AA) increased and that of palmitic acid decreased significantly after borage oil administration. In serum CE dihomogamma-linolenic acid increased whereas docosahexaenoic acid decreased significantly. In this lipid class, AA and the sum of AA plus its precursor, dihomogamma-linolenic acid, increased significantly with the dose fed. A positive correlation was found between change in vital capacity and change in linoleic acid content of serum CE and AA content of serum PL.

ISSN:0250-6807    

DOI:10.1159/000177792

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Esterification processes of oleic (OA), linoleic (LA) and arachidonic acids (AA) were investigated in mouse jejunal explants with some references to age (2.5, 12 and 21 months) of the animal tissue donors. Explants were incubated either for 15 min in a stirred medium enriched with lipids or cultured for 15 min in Falcon dishes in a culture medium enriched with lipids, then for 6 h in a lipid-free medium. In 2.5-month-old mice, released lipoprotein OA secreted in the medium was especially integrated into the triacylglycerols, while LA was significantly integrated into glycerophospholipids. Triacylglycerol formation from released AA was always significantly lower than from OA. With increasing age of the animals, decreasing amounts of OA appeared in triacylglycerols. The preferential association of OA with triacylglycerols observed in jejunal explants coincided with a preferential esterification of OA observed with the enzymatic assays. The utilization of the arachidonoyl-coenzyme A by the microsomal acyltransferase was low at all ages.

ISSN:0250-6807    

DOI:10.1159/000177793

出版商:S. Karger AG    

年代:1994

数据来源: Karger