[Results of studies of carbohydrate metabolism and ultrasonography of the pancreas in man after continuous anti-orthostatic hypokinesia]. / Rezul'taty issledovanii sostoianiia uglevodnogo obmena i ul'trazvukovoi kartiny podzheludochnoi zhelezy u cheloveka pri dlitel'noi antiortostaticheskoi gipokinezii.

Data on the hypokinesia-induced transformation of the glycemic profile and ultrasonic changes in the pancreas structure are presented. The AOH study gave further evidence of transforming glycemic curves. Moreover, increased sizes of tail and head of the pancreas and a decrease in its echogeneity were observed in all test-subjects. Structural changes in the pancreas were confirmed by biochemical investigations which revealed increased levels of blood enzymes and activation of insulin secretion. Increases in the liver size, thickness of the wall of the stomach, diameter of the splenic vein were indicative of progressing venous plethora in the portal vein system. It was shown that venous plethora are the main cause for changes in the upper GI, and in the pancreas state in particular, which can be qualified as dysfunctional. These structural changes in the pancreas could suppress its functional activity manifested by increases in blood enzymes and hormones and transformation of the glycemic profile during the glucose load.

[The development of the syndrome of congestive parenchymatous organs under conditions of short-term hypokinesia]. / Razvitie sindroma zastoinykh parenkhimatoznykh organov v usloviiakh kratkovremennoi gipokinezii.

Five series of head-down (-10 degrees to -30 degrees, up to 18 hr) tilt tests were performed with participation of 65 healthy male subjects. The ultrasonic technique was used to investigate the liver, spleen, pancreas, kidney, and the main abdominal vessels, i.e. aorta in the abdomen and superior mesenteric artery, interior caval, portal, and splenic veins. A few hours of HDT already brought about a complex of load-deprivation reflexes (the syndrome of stagnant parenchymal organs) characterized by a prolonged venous congestion in the abdominal organs-vessels system, increases in sizes and blood filling of the liver, spleen, pancreas, kidney, and the main arteries and veins in this hemodynamic region. This was the first time when increases in pancreas including its head, body and tail, and the abdominal blood vessels were quantified at the beginning of adaptation to HDT. The load-deprivation reflexes arising in this period were hemodynamic by nature. Considering the significant functional strain of the abdominal organs and vessels and particularly the limited control of excessive blood flow towards the pancreas and kidneys, there is a good reason to look into the ways to improve the existing countermeasures against the consequences of immobilization for humans both in general clinic and preventive medicine, and in short- and long-term space missions.

Ultrasonic research of abdominal organs in conditions of long-term antiorthostatic hypokinesia.

Change in functional activity of digestive system in space flight usually is associated with phenomenon of hypokinesia which takes place in microgravity. However, it is marked that the reorganization of a gastrointestinal tract in space flight occurs on a background of the phenomenon of venous plethora in abdominal cavity, which can also result in changes of functional activity in organs of digestive system. Insignificant amount of studies of venous plethora in abdominal cavity carried out in conditions of space flight does not allow to create a complete picture of this phenomenon. Hemodynamical changes comparable to microgravity are well-simulated in conditions of a long-term antiorthostatic hypokinesia (AH)--bed-rest in a head-down tilt. The present research was performed with the aim to study venous plethora in abdominal cavity in conditions of long-term AH.