CORRELATION OF MANOMETRIC AND HISTOCHEMICAL TECHNIQUES IN THE STUDY OF CHOLINESTERASE ACTIVITYHARRIS, CHARLES; COHEN, BERNARD S.; BERGNER, A. DOROTHY
doi: 10.1177/1.6.405pmid: 13118121
1. A relationship is defined for the manometric equivalent of the activity of cholinesterase which will precipitate a minimally visible deposit of copper sulfide, when Koelle's technique for demonstration of cholinesterase is applied to plasma and erythrocyte enzyme preparations.2. Were the equations for the histochemical reactions exactly defined, with particular reference to the structural formula of copper thiocholine, the equivalence could be calculated from the stoichiometric equations. In the absence of exact knowledge of the equations, equivalence is estimated by techniques which adapt a filter paper matrix as substitute for tissue.3. Calculations are limited to order of magnitude at minimal staining, so that surface deposits of copper sulfide can be studied without reference to their depth.4. The motor end-plate of rat intercostal muscle, with surface area of about 500 sq. micra is shown to have a cholinesterase activity of an order of magnitude capable of hydrolyzing 2.5 x 10–6 microliters of carbon dioxide in 30 minutes.5. The cholinesterase activity of rat erythrocyte is estimated as being below the threshold of activity per unit area necessary to result in a visible precipitate of copper sulfide with the histochemical method employed.
THE QUANTITATIVE HISTOCHEMISTRY OF THE BRAIN LOWRY, OLIVER H.
doi: 10.1177/1.6.420pmid: 13118123
The general histochemical procedure of Linderstrøm-Lang and Holter has been altered to permit direct histological control and the use of smaller samples. Frozen sections are dried at –30°C. From the dry sections are cut out identified regions as small as 100 x 100 x 20µ (0.2γ wet weight). The chemical analysis of these fragments may be based on either their protein content, their dry weight or their volume. The weight and volume measurements are described and validated. The revised technique is not limited in applicability to the nervous system.
THE DISTRIBUTION OF GLUCOSE-6-PHOSPHATASE IN THE LIVER AND KIDNEY OF THE MOUSECHIQUOINE, A. DUNCAN
doi: 10.1177/1.6.429pmid: 13118124
Glucose-6-phosphatase has been demonstrated in frozen sections of mouse liver and kidney. In both organs, the enzyme is present only within parenchymal elements and is absent from stromal tissues. The enzyme is more abundant in the peripheral third of the hepatic lobule than in the inner two-thirds. Within the hepatic cell the enzyme is concentrated about the nuclear membrane. Studies were made of the distribution of the enzyme in the liver in relation to the diurnal cycle but no significant changes in enzyme distribution were observed. In the kidney the enzyme is found in the proximal convoluted tubule, concentrated at the basal pole of the cells, and in portions of the renal glomerulus. The evidence and experimental results are described which indicate that glucose-6-phosphatase is an enzyme distinct from nonspecific acid and alkaline phosphatases and that this enzyme can be so demonstrated histochemically. The presence of this enzyme in the liver and kidney is correlated with the ability of these organs to produce blood-sugar.
LIBERATION, DIFFUSION, AND PRECIPITATION OF PHOSPHATE IN THE GOMORI TESTJOHANSEN, GORDON; LINDERSTRØM-LANG, K.
doi: 10.1177/1.6.442pmid: 13118126
On the basis of recent X-ray and electron microscopic investigations by Carlsen, Jensen, and Johansen, and in connection with the article by Gomori and Benditt, the question of liberation, diffusion, and precipitation of calcium phosphate in the Gomori test has been discussed again. In spite of several modifications of our picture of the precipitation of calcium phosphate we maintain that the Gomori test for phosphatase distribution within a single cell still needs a thorough experimental investigation before it is put into the hands of the cytologists as a routine method.
THE HISTOCHEMICAL DEMONSTRATION OF CYSTINE-CONTAINING STRUCTURES BY METHODS INVOLVING ALKALINE HYDROLYSIS PEARSE, A. G. EVERSON
doi: 10.1177/1.6.460pmid: 13118128
1) Hydrolysis of combined cystine at pH 12.8 gives rise to reaction products capable of converting soluble, relatively colourless, tetrazolium salts into insoluble formazan dyes.2) Both normal and abnormal keratins are demonstrated by the reaction.3) Cystine-free structures which also reduce tetrazolium salts at pH 12.8 are present in tissue sections. These are either lipid-containing or reducing sugar-containing, but distinction between these two groups and the cystine-containing group of structures is histochemically possible.4) The alkaline tetrazolium reaction is considered to form the basis of a useful method both for research into the process of keratinisation and also for the routine diagnosis of abnormal tumour keratins.
HISTOCHEMICAL STUDY OF THE DISTRIBUTION OF ESTERASESCHESSICK, RICHARD D.
doi: 10.1177/1.6.471pmid: 13118130
The histochemical localization of esterases using α-naphthyl acetate and naphthol AS acetate as substrates is described for the five mammalian species: man, rabbit, rat, cat, and mouse. The localization overlaps in some places, but in others there are wide differences in the pattern of distribution, varying with the substrate and species employed in the study. This is interpreted as further evidence for the existence of an "esterase spectrum" consisting of a group of more or less specialized enzymes acting on certain specific esters of carboxylic acids, with a variable amount of overlap depending on the substrate and species used. Certain specific findings reported in the previous literature are now considered due to diffusion artifacts.