Ramon M. Fusaro

The quantitative enzymic determination of animal liver glycogen

Abstract A previously reported enzymic technique has been applied to the quantitative determination of glycogen in animal liver and the results have been evaluated. The results of analysis of glycogen isolated by ethanol precipitation from KOH digests have been compared with those obtained by direct enzymic assay. The lower values obtained for KOH glycogen were largely accounted for by the detection of oligoglucosides which do not precipitate as glycogen under the conditions employed for isolation of KOH glycogen. Consideration of the mechanism of the action of concentrated alkali on glycogen lead to the proposal that extensive degradation of oligoglucosides occurs in the presence of hot concentrated KOH. In conjunction with the development of a direct assay for liver glycogen, a reliable method for determining tissue glucose was established. Reproducibility of the analytical methods deseribed in this report was evaluated by statistical analysis of data obtained from replicate assays, and by the recovery of known quantities of carbohydrate added to test samples.

An enzymic method for the quantitative determination of glycogen

Abstract A convenient enzymic method has been developed for the quantitative determination of glycogen. Using this method, we have obtained consistent, reproducible results for glycogen solutions in the concentration range of 6 to 18 μg glycogen/ml of test solution. The enzyme mixture has been shown to effect 92–96% conversion of glycogen to glucose, and shows little species differentiation between rabbit liver and human liver glycogen.

AN ENZYMIC METHOD FOR THE QUANTITATIVE DETERMINATION OF MICRO QUANTITIES OF GLYCOGEN.

Abstract In an earlier report (1), we described an enzymic method for the quantitative determination of glycogen. Our previous report describes the application of our method to relatively large amounts of glycogen: 6, 12, and 18 μg/ml test solution in a final volume of 3.5 ml. Since the method is easy to apply and involves a minimum number of mechanical operations, we have been able to adapt it to micro volumetric procedures with no loss in accuracy. The purpose of the present report is to describe the results of these experiments.

Enzymic analysis of rabbit skeletal muscle carbohydrate

Abstract 1. 1. The enzymic techniques employed for the analysis of animal liver carbohydrate were applied to rabbit skeletal muscle, and quantitative and statistical data are presented. 2. 2. Glycogen determination based on direct analysis of neutralized KOH muscle digest is evaluated. 3. 3. A simple technique for oligoglucoside assay by analysis of deproteinized tissue homogenate is outlined. 4. 4. Glucose, oligoglucoside, and glycogen contents of rabbit muscle specimens obtained under a variety of experimental conditions are presented, and the implications of the observed changes in carbohydrate distribution are discussed briefly. 5. 5. Practical aspects of enzymic glycogen assay and its adaptability to microdetermination are discussed.

Enzymic analysis of rat liver carbohydrate: Glucose and oligoglucoside contents as additional indices in metabolic studies

Abstract A technique for the enzymic determination of oligoglucosides in liver homogenate has been described and evaluated. Examples were cited to illustrate the utility of determining glucose and oligoglucoside contents in the investigation of in vivo and in vitro liver carbohydrate metabolism. The reliability of routine application of the analytical methods employed in this investigation was evaluated by performing repeat assays of several homogenates. Although numerous liver homogenates with high glycogen and low oligoglucoside contents have been analyzed, detectable quantities of oligoglucosides were present in each specimen.

Antigenic relationships between lens, epidermis and other bovine tissues

Abstract A rabbit antiserum was prepared against a lens fraction which constituted 20% of the soluble bovine lens protein. Immunoelectrophoresis demonstrated that the antiserum formed numerous precipitin arcs against lens, none against serum, a single characteristic arc against erythrocyte hemolysate, and at least five against epidermis. The results of an immunoelectrophoretic survey of soluble cross reacting antigenic determinants between lens and other bovine organs are enumerated. Osserman immunoelectrophoretic identity reactions were conducted between epidermal antigens resolved by electrophoresis, and those of various tissues. In addition to at least two obvious identity reactions in several tissues, a tentative one is defined as a change in shape of an epidermal arc. These conclusions are supported by treatment of lens antisera with kidney and liver powders, which indicate that some of the determinants contained in the epidermis cross react with those of the two powders. The advantage of using the identity reaction, in conjunction with absorption studies, to establish the immunologic identity or nonidentity of antigens in two tissues is discussed.

Optimal conditions for immunoelectrophoresis of some soluble bovine lens antigens.

It was demonstrated that the conventional conditions for immunoelectrophoresis of lens antigens with respect to pH, temperature and specific conductance of buffer may not be adequate. The best results were obtained with a Tris-phosphate buffer with a specific conductance equivalent to that of 0·025 m KCl, at 4°C with a pH of 6·0–7·5. The optimum conditions, however, varied depending upon which lens antigen was being studied. Immunization of rabbits to bovine lens antigens was considerably more successful when relatively purified protein fractions were utilized rather than the total soluble lens protein fraction.

CUTANEOUS EXTRACELLULAR GLUCOSE KINETICS IN ACNE PATIENTS RECEIVING PHENFORMIN

The clinical manifestations of acne are influenced by dietary intake. Upon reviewing the literature,’ it is apparent that one cannot find conclusive evidence that implicates carbohydrates or fats as the dietary culprit in acne flareups. Because carbohydrates were implicated, several agents that affect carbohydrate metabolism have been used clinically and reported to have beneficial effects on the course of the disease. In unpublished clinical trials, phenformin was found to be of therapeutic value in patients with acne.2 Our study was done in order to measure glucose concentration and kinetics in the blood and skin of a small group of acne patients taking phenformin.