Phenol Red Solution Research Articles

Measurement of gastrointestinal transit of solid food using a colestipol-phenol red complex as a marker.

The present study was undertaken to determine whether colestipol-phenol red complexes can be used as markers for gastrointestinal transit of solid food. Colestipol (1.0g) bound completely with phenol red (10 mg) to form a stable complex in water (pH 7.0) Phenol red was more readily eluted from colestipol with 20 ml of 1 N HCl than 1 N NaOH, but was not eluted with 0.1 N HCL (pH 1.0). It was therefore assumed that the complex would remain stable in the gastrointestinal tract. Also, phenol red in the gastrointestinal tract was quantitatively eluted from the complex with 20 ml of 1N HCl. In a study on gastric emptying, phenol red solution (liquid food) was excreted from the stomach in a zero-order manner, and the colestipol-phenol red complex (solid food) in a first-order manner. It was concluded that colestipol-phenol red complexes can be used as markers of gastrointestinal transit.

Measurement of gastro-oesophageal reflux after antacid administration using a perfusion technique.

A study was carried out to measure gastro-oesophageal reflux in 6 asymptomatic and 9 heartburn subjects using a perfusion technique. Subjects swallowed a multi-lumen tube and the lower oesophageal sphincter pressure was measured. A phenol red solution was then infused through it into the stomach for 90 minutes whilst the oesophagus was aspirated continuously. The quantity of phenol red in oesophageal and gastric aspirates over 10-minutes periods was measured. In the heartburn subjects reflux was 1.27 +/- 0.37 ml/min and in the control subjects 0.23 +/- 0.07 ml/min, (p = 0.02). After 10 ml of an antacid combination, reflux in heartburn subjects was reduced to 0.59 +/- 0.18 ml/min and 0.68 +/- 0.16 ml/min in the second and third 30-minute period. Sphincter pressures increased from 8.9 to 11.8 mmHg. Control subjects showed little change in sphincter pressure or reflux after the antacid. Serum gastrin and secretin levels did not change in either group. This technique enables gastro-oesophageal flow rates to be easily measured. The results suggest that antacid administration tends to normalize lower oesophageal sphincter pressure and gastro-oesophageal reflux in patients with heartburn.

Abdominal vagotomy inhibits osmotically induced drinking in the rat.

After complete bilateral transection of the abdominal vagus (Vgx-C), with the hepatic branch left intact, rats drank later and less than normal after cellular dehydration induced by intraperitoneal hypertonic saline. When access to water was delayed for 1 hr after cellular dehydration, Vgx-C rats initiated drinking quickly with normal latency, but (a) a gastric water preload was a more effective stimulus for drinking suppression in Vgx-C than in normal rats; (b) gastric emptying of a water or phenol red solution preload was more rapid in Vgx-C than in normal rats; and (c) when gastric emptying dysfunction in Vgx-C rats was removed by having rats sham drink, Vgx-C and normal rats sham drank equivalent amounts of water. Thus, disordered preabsorptive satiety caused by abnormally rapid gastric emptying of water is a factor in the decreased drinking of Vgx-C rats after cellular dehydration. Disordered satiety for ingested water cannot, however, account for the abnormal latency to initiate drinking after cellular dehydration in Vgx-C rats.

Effect of anti-parkinsonism drugs on gastric emptying and intestinal transit in the rat.

The effect of atropine sulfate, trihexyphenidyl HCl, benztropine mesylate, diphenhydramine HCl and ethopropazine HCl on gastric emptying and intestinal transit of a phenol red solution in the rat was examined. Intraperitoneal administration of 0.3 mg/kg atropine, 1.2 mg/kg benztropine and trihexyphenidyl results in a marked decrease in gastric emptying and intestinal transit rate when compared to controls. Oral administration of these agents produced variable and unpredictable results. Single and multiple oral dose (0.6--3 mg/kg) studies with trihexyphenidyl failed to produce any significant decreases in gastric emptying rates. A single oral dose of benztropine (0.6--3 mg/kg) failed to reduce the gastric emptying rate, but multiple dose studies produced a significant decrease in the gastric emptying rate. Effects on gastric emptying and intestinal transit were seen after single and multiple oral doses of diphenhydramine and ethopropazine.

A technique for the sampling and analysis of halogenated hydrocarbons in air.

Abstract The low Threshold Limit Values (TLV) of halogenated hydrocarbons tax the sensitivity of the conventional analytical techniques used for their quantitative analysis in air. A combustion tube technique using a phenol red absorbing solution is described which can detect one-tenth of the present TLV's of methyl iodine, methyl bromide and carbon tetrachloride and concentrations of one ppm or less of other halogenated hydrocarbons in a 10-liter air sample.

変法トリプシン培地によるエルトール菌とコレラ菌の鑑別

The modification of the formula of 0.9% trypsin broth which was devised by Gan and Tjia in 1962 for the differentiation of V. cholerae and V. eltor was investigated. According to the experimental results, the formula and method of preparation was modified as follows: trypsin (1:250, Difco) is suspended in 2% peptone water at the level of 0.4%, well mixed and stirred for 15 minutes, kept at a room temperature for one hour, then the pH of the medium adjusted to 7.4-7.6. After 1.2ml of 0.2% phenol red solution is added to 100ml of the medium, it is boiled for 10 midutes, filtrated with filter paper, and sterilized at 115°C for 15 minutes. Before using it, the medium is distributed into small test tubes in one ml quantities aseptically.After incubation at 37°C for 18-24 hours, yellow coloration of the medium indicates V. cholerae, while deepred coloration of the surface layer of the medium indicates V. eltor. All cultural reactions are very clearcut and the reading is easy.As the ingredient of this medium it is recommanded to use trypsin (1:250, Difco). All other samples of trypsin are inadequate for this purpose.

INHIBITION OF GASTRIC EMPTYING IN MICE BY BACTERIAL ENDOTOXINS.

Mice injected with bacterial endotoxins exhibit a rapid reduction of food and water intake, to a degree dependent on the magnitude of the dose. Using phenol red solution as a tracer, it has been demonstrated that gastric emptying is inhibited by endotoxin injection; that the effect is rapid (within 10–15 min); and that it occurs whether the endotoxin is injected intraperitoneally or intravenously. With four different endotoxin preparations, inhibition is maximal at one-tenth of the ld50. Significant inhibition may be caused by between 1/20 and 1/100 of an ld50, depending on the preparation used. Injection of cortisone acetate reduces the inhibition of gastric emptying caused by endotoxin injection; intravenously injected Proferrin, however, does not increase the response, although it sensitizes the mouse to the lethal effects of endotoxin.

Colorimetric method for estimating number of cells in monolayer cultures without physiological damage.

SummaryA method has been presented for determining the number of cells in monolayer cultures of monkey kidney cells without physiologically damaging them. The method consists of determining the change in absorption of a phenol red solution after a 15-second exposure of the cultures under standard conditions. These conditions include the use of a standard solution defined with respect to pH, quantity of titratable phenol red, and buffering salt, and the use of the same type of glass in the different cultures. The change in absorption appears to be a simple consequence of the production of hydrogen ion by the cells. It is critically dependent on the presence of potassium but independent of an exogenous carbon source, and, independent of endogenous polysaccharide reserves over a wide range. The amount of hydrogen ion produced may be sufficiently independent of cell age and metabolism to be a reliable method for the estimation of growth in cultures.

Further Studies of Agar-slant Tissue Cultures of Typhus Rickettsiae.

In a preliminary note published in these Proceedings, the writers described an agar-slant-tissue method for the cultivation of Rickettsiæ, both of the murine and of the classical types of typhus fever. Further study of this method has led to modifications and standardizations which are reported herewith in order to facilitate its use in the hands of others. Preliminary experiments by Pinkerton with Rocky Mountain Spotted Fever virus indicate a possibility that the method may be successful with Rickettsiæ other than those of typhus. The medium as now used differs from the original only in proportions of ingredients. We have found that results are most regular when the agar is prepared as follows: A “Tyrode” solution of the ordinary formula is made up double strength throughout, except that only 1 gm. of bicarbonate of sodium is used per liter. The agar used is a Difco granular Bactoagar. A mixture of 150 cc. double strength Tyrode and 150 cc. of horse serum with 8 cc. of phenol red solution is filtered through a Seitz filter. To the filtrate is added 150 cc. of 4% agar in distilled water, cooled to 45°C.

Cell Models Representing Various Types of Living Cells

The behavior of a variety of cells can be roughly imitated by models consisting of a non-aqueous substance (representing the plasma membrane) placed between dye solution and artificial sap (representing vacuolar sap). The rates of penetration of dye into the sap are compared during one hour. The range of pH values studied is between pH 5 and pH 9. (1) When chloroformis used as the membrane. (a) Penetration of dye from cresyl blue solution at pH 9 into the sap at pH 5 has a high temperature coefficient (Q10 = 2.3 between 15° and 25°C.) This may depend on the change in the viscosity of chloroform. A similar explanation may account for the high temperature coefficient in the penetration of the dye into the sap of Nitella and Valonia. (b) From cresyl blue solution at pH 9 the dye accumulates rapidly in the sap at pH 5 as in Nitella. (2) When aniline is used as the membrane, (a) The higher the pH value of the cresyl blue solution and lower the pH value of the sap, the more rapid is the rate of penetration and accumulation of dye in the sap. From the solution at pH 9, the dye passes into aniline chiefly as the dye base and upon reaching the sap it is converted to the dye salt. From the solution at pH 5 the dye passes into aniline chiefly as dye salt, (b) The lower the pH value of a phenol red solution and higher the pH value of the sap, the greater is the rate of penetration and accumulation of dye in the sap. The dye accumulates rapidly in the sap at a high pH from phenol red solution at low pH; the dye passes into aniline as free acid (yellow) and is converted by the sap to the dye salt (red).

Experiments concerning the question of secretion of phenolsulphone-phthalein by the renal tubule

Among the most important methods of study which have been applied to the question of secretion by the renal tubule are those which involve the use of dyes. Heidenhain revived the Bowman theory of secretion, largely because of his observations relating to the elimination of indigo carmin—observations which form the beginning of a voluminous and confusing literature. The importance of complete information concerning the mode of excretion of certain dyes can scarcely be denied: they resemble most of the normal urinary con­stituents in that the concentration in which, after injection, they appear in the urine is higher than that in the blood. As has frequently been argued, if the mechanisms which take part in the excretion of these substances can be identi­fied, light will be thrown upon the processes of normal urine formation. The experimental advantage which derives from their colour is obvious. Phenolsulphonephthalein (phenol red) was introduced as a clinical test of renal function by Rowntree and Geraghty(1) in 1912. Among their experi­ments was one which convinced them that the tubule was actively concerned in its elimination. After section of the renal arteries in the frog, a phenol-red solution was perfused through the renal portal vessels at a pressure of 35 cm. water. The resulting appearance of the dye in the ureteral fluid convinced them that it had been “secreted” by the tubule. It was soon shown by Bainbridge, Collins and Menzies(2), however, that such high pressure in the renal portal vessels may drive fluid through the efferent vessels into the glome­ruli; thus their “proof” that the glomeruli had not been involved in the observed excretion was invalidated.