ABSTRACT
The spectrum of bile acids and bile lipids in men exposed to 120-day head-down tilt was investigated. The test subjects were subdivided in to four groups: group 1-bed rest per se, group 2-bed rest + exercise, group 3-bed rest + drugs normalizing calcium metabolism, and group 4-bed rest + exercise + drugs. It was anticipated that biliary concrements would primarily be formed in group 1 and 2 subjects. They showed a low level of bile acids and a high content of total Ca and cholesterol in the bile, which was more pronounced in the C portion (decrease of the cholate/cholesterol coefficient). Group 2 subjects displayed a modified synthetic function of the liver: prevalence of tauroconjugates in the bile (decrease of the ratio of glucoconjugates to tauroconjugates). Group 3 and 4 subjects showed a faster synthesis of bile acids in the liver and a lower content of total calcium and cholesterol in the bile, the latter being more distinct in group 4 subjects. Positive dynamics of these parameters is a factor responsible for a reduced lithogeny of the bile. However, the test subjects of these groups exhibited hazardous changes that may be responsible for concrement formation. This is indicated by a lower concentration of the lipid complex in the bile, possibly at the expense of a lower content of phospholipids. This emphasizes the necessity of further search for prophylactic procedures aimed at normalizing the synthetic function of the liver under hypokinetic conditions.
Subject(s)
Bed Rest , Bile Acids and Salts/analysis , Bile/analysis , Lipids/analysis , Posture , Adult , Bile/drug effects , Bile/metabolism , Calcium/analysis , Calcium/metabolism , Chromatography, Thin Layer , Humans , Male , Physical Exertion , Spectrophotometry, Atomic , Time FactorsABSTRACT
Twenty one test subjects exposed to head-down tilt for 120 days were subdivided to four groups: Group 1--nine subjects used as controls, Group 2--three bed rested subjects who performed regular exercises, Group 3--four bed rested subjects who were given selected drugs, including Vitamin F-99 that influenced lipid metabolism, and Group 4--four bed rested subjects who performed regular exercises and received Vitamin F-99. At different stages of bed rest and recovery the content of lipoprotein fractions and lipids of different classes in serum was measured by thin-layer chromatography. The concentration of cholesterol in biliary lipids was determined. In Group 1 and 2 subjects bed rest led to a drastic and significant increase of cholesterol esters in blood, a decrease of phospholipids, variations of triglycerides and non-esterified fatty acids, and a lower percentage content of alpha-lipoproteins. The use of Vitamin F-99 produced positive changes in the above parameters of lipid metabolism (it normalized the level of cholesterol and phospholipids). In Group 4 subjects the effect of exercise combined with drugs was most distinct.
Subject(s)
Lipids/blood , Posture , Bed Rest , Bile/metabolism , Cholesterol/metabolism , Drug Combinations/therapeutic use , Humans , Linoleic Acids/therapeutic use , Linolenic Acids/therapeutic use , Lipoproteins, HDL/blood , Lipoproteins, LDL/blood , Physical Exertion , Time FactorsABSTRACT
Using present-day techniques, we measured the activity of pancreatic lipase in the serum and duodenal juice, the activity of monoglyceride lipase in the duodenal juice, the concentration of lipoproteins in the bile, the activity of intestinal enzymes (monoglyceride lipase and alkaline phosphatase) and the concentration of lipid fractions in the feces. These parameters were determined in six test subjects who were exposed to head-down tilt (-4.5 degrees) for 120 days. Our findings suggest that bed rest decreases lipolytic enzymes in the duodenal juice and increases pancreatic lipase in the serum. The exposure also leads to a decrease of the lipoproteins in the bile, rearrangement of the lipolytic enzymes in the intestine, and to an increase of mono-, di- and triglycerides in the feces. Our results are indicative of changes in the pancreatic function and in lipid hydrolysis and absorption. They can be interpreted as compensatory-adaptive processes of the digestive organs.
Subject(s)
Immobilization , Lipid Metabolism , Posture , Alkaline Phosphatase/metabolism , Duodenum/metabolism , Feces/enzymology , Humans , Hydrolysis , Intestinal Secretions/metabolism , Lipase/metabolism , Male , Monoacylglycerol Lipases/metabolism , Pancreas/enzymologyABSTRACT
The composition of bile acids in the B and C portions of the duodenal juice of six essentially healthy test subjects exposed to 120-day head-down bed rest was investigated. As the exposure continued, the percentage content of bile acids conjugated with taurine increased and that of bile acids conjugated with glycine decreased. The rapid and significant decrease of the ratio of glycine conjugated to taurine conjugated bile acids suggests a specific modification of the synthetic function of hepatocytes under the above conditions.
Subject(s)
Bed Rest , Bile Acids and Salts/analysis , Posture , Adult , Chromatography, Thin Layer , Duodenum , Humans , Intestinal Secretions/analysis , Time FactorsABSTRACT
The lipid spectrum and lipolytic activity of the duodenal contents of an endogenous dense fraction of the chyme and mucous depositions were studied in small intestine. A considerable augmentation of the lipase activity was found in endogenous dense fraction of the chyme and in mucous depositions as compared to the duodenal juice activity.
Subject(s)
Intestinal Secretions/metabolism , Lipids/analysis , Lipolysis , Animals , Dogs , Intestinal Secretions/enzymology , Lipase/metabolism , Monoacylglycerol Lipases/metabolism , PancreasABSTRACT
The enzyme-excretory and motor functions of the gastrointestinal tract of rats flown for 18.5 days onboard the biosatellite Cosmos-1129 were studied. Immediately postflight, the pepsin synthesis decreased and the dipeptide parietal hydrolysis increased. At R + 6, the activity of the enzymes responsible for the cavitary and parietal hydrolysis of lipids significantly grew and that of the enzymes involved in protein hydrolysis fell. At R + 30, the carbohydrate hydrolysis was inhibited and the activity of lipolytic enzymes enhanced markedly. The amplitude and rhythm of stomach biopotentials were dysbalanced. The so-called immobilization stress of intact rats brought about activation of lipase, monoglyceridyl lipase, dipeptidase and inhibition of amylase and invertase. The immobilization exposure of flight rats caused inhibition of the membrane hydrolysis of proteins and carbohydrates and lack of the pancreatic reaction.