Aqueous hypophase

Figure 4. Electrolyte (150 mequiv CaCl.) injected under DPL-DPPA mixed films. Kinetic curves of AV of films containing 10 wt % (upper panel) and 50 wt % (lower panel) DPPA at three different values of x (2,10, and 20 dyn/cm). Aqueous hypophase, pH 5.6, 25°C. The mixed-lipia film at the indicated pressure was spread first on distilled H 0 the electrolyte then was injected beneath at time zero. Error as in Figure 2.

Alkyl sulphuric acids are known to be as acidic as sulphuric acid itself and to form inorganic salts readily [13]. In the general procedure [11], the sulphur trioxide/pyridine complex, in excess, and the respective carotenol are mixed at -10°C and the reaction, monitored by TLC, is allowed to proceed at room temperature. The reaction is quenched either by the addition of 10% aqueous NaOH to ca. pH 9, or by the addition of an aqueous NaCl solution. The carotenoids are extracted with ethyl acetate (or for disulphates with chloroform-methanol) from the aqueous hypophase and separated by TLC. 

An aqueous hypophase lies beneath the surface film and above the epithelium. Its thickness may vary depending on its location within the alveolus (74). The hypophase has an amorphous structure and contains proteins, proteoglycans, lipoproteins, lipid micelles, and tubular myelin (78). 

Figure 7 Diagram of mucous blanket of the conducting airways Although the exact structure of the mucous layer of the airways is unknown, the diagram shows some of the features that have been demonstrated in recent light and electron microscopic studies. An osmiophilic film is seen at the air-liquid interface, which has a multilaminated appearance and exists in various degrees of thickness (see inset). Beneath this surfactant film lies an aqueous hypophase, again of variable thickness, in which are found macrophages, mucus, and osmiophilic lamellar structures. CC, Clara cell CEP, ciliated epithelial cell GC, goblet cell.

Add 10 to 15 ml half-saturated NaCl solution under continued gentle shaking until the hypophase (lower phase), which contains the original organic solvent (e.g., acetone), is -50% aqueous and the chlorophylls and carotenoids are transferred to the organic epiphase. 

In various attempts at establishing the stoichiometry of an eventual interaction of Ca++ with lecithin films, the increases in surface radioactivity observed in the presence of 45Ca++ in the aqueous phase were ascribed to adsorption of Ca+ Apart from the interpretations, the data themselves in this field are interestingly discordant (13,14,15). To appreciate the significance of the statement, we first present our own data from experiments in which the excess surface radioactivity in counts per minute (A cpm) in the presence of DPL film (cpm with DPL — cpm without DPL) are related to the hypophase pH the aqueous phase contained 150mM NaCl and 93/xM CaCl2 carrier (see Figure 6). 

The lamellar body contents are secreted from the apices of the type 11 cells into the alveoli. Secretion appears to involve membrane fusion and exocytosis into the hypophase between the cell and the air surface. After their release, the lamellar bodies become hydrated in the aqueous subphase and unravel into a matrix of tubular myelin (Fig. 2). Tubular myelin is hypothesized to release phospholipid spontaneously to the air-liquid interface where the phospholipids reside in thermodynamically favorable orientation with the acyl chains extending into the air phase, whereas the head groups remain submerged in the aqueous phase. After one or several respiratory cycles, the surfactant material is then forced back into the aqueous phase, where the surfactant forms bilayer vesicles. The vesicles may then enter into either a recycling or degradative pathway (31). 

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