Manometric research methods

Manometric research methods - a set of methods, based on the determination of pressure of gas or fluid, using various systems of manometers. At physiological research and in medical practice gauge research methods used to determine the pressure of the blood or lymph (intravenous, intraintimate, intracranial, blood pressure). In biochemical research gauge research methods used for studying tissue exchange, determination of blood gases, intermediate products exchange and also separate activity of enzyme systems. Thus determine the amount of gas produced or endangered in the process of one or another reaction in a closed system.
Determination of blood gases by van Sliku - see van slice method.
Determination of blood gases by Barcroft spend in the office of Barcroft (Fig. 1), which consists of two identical volume and shape of the veins, United by the gauge. Both fill the vessel with the same quantity of the reaction mixture; emission or absorption of the gas is usually done in one of vessels and the amount of gas judged by differential pressure manometer. The displace oxygen from emulsionnoj blood saturated solution K3Fe(CN6), carbon dioxide - tartaric acid. Pre-determine the constant of the instrument (for each of the vessels), i.e., measure the amount of gas that causes a shift of levels in the gauge of 1 mm Multiplying the value of the constants found in the experience of the pressure difference, find the amount of gas taken in blood meal.
The device Versera (Fig. 2) is a modified machine Barcroft: it put additional pressure gauge, one knee which, coupled with the main gauge, graduated in volumetric units; the second knee additional gauge ends rubber tank, capacity of which can be changed by squeezing its walls a screw clip. When using the device Versera there is no need to determine the constant of the instrument, because the volume of gas evolved is measured directly from the reading of additional gauge before and after equalization of the levels in the main gauge due to changes in the capacitance of the rubber bladder.
The study of tissue exchange Warburg. About formation or disappearance of gas is measured by change of pressure in the system (a small glass container, connected with manometer) after bringing gas to the initial volume. The study of breathing is carried out by determining the absorption of oxygen by the tissue section, kasetami, homogenates, structural elements cells placed in buffer solutions. The quantity of consumed oxygen expect to reduce the pressure in the system. Released in the process of exchange of carbon dioxide absorbed by alkali (see Warburg apparatus).
Determination of gas exchange in tissues is reduced to account for consumed tissue of oxygen and selection of carbon dioxide. The definition of carbon dioxide carried out in two ways: 1) carbonic acid, associated with alkali, replacing a strong acid and is determined by the increase of the gas pressure in the system; 2) two devices are determining the absorption of oxygen cloth. In one instrument to absorb CO2 in the additional tank filled with alkali, in another lye there and formed in the process of exchange of carbon dioxide is released into the gas space. This partially compensates for the decrease in pressure in the system due to the absorption of oxygen. On a difference of pressure in both devices calculate the quantity of released carbon dioxide. The second method is less precise but more simple and can be used in most cases studies.
Method Warburg can be used to explore any enzyme system that catalyzes a reaction that directly or indirectly related to education or absorption of gas.
The definition of intermediate products of tissue exchange method Warburg possible using various enzymatic or chemical reactions leading to the formation or acquisition of gas (mostly CO2 and O2) in amounts equivalent to the amount of analyte (definition amber, pyruvic, α ketoglutarova, glutamine, fumaric acid, xantina, gipoksantina, series L-amino acids). Currently gauge research methods intermediate products of tissue exchange, more and more are displaced, less time consuming specific methods of chromatographic analysis (see Chromatography).
Fig. 1. The Staff Of Barcroft.
Fig. 2. The Device Versera.