Piero P. Foà

Radioimmunoassay of insulin in fishes, experiments in Vivo and in Vitro ☆

This paper describes an adaptation of the radioimmunoassay of Hales and Randle for the determination of insulin levels in fish serum and in media used for the incubation of fish islets. Using codfish insulin as a reference standard, guinea pig anticod insulin serum, and 125I-labeled cod insulin, instead of the standard mammalian components, the average fasting serum insulin level (±SEM) was found to be 36 ± 9 μU/ml in goldfish (Carassius auratus) and 19 ± 6 μU/ml in toadfish (Opsanus tau). Serum insulin levels of fed goldfish were nearly double that of fasted fish. Glucose (40 or 100 mg/100 ml) or leucine (1 mg/ml), stimulated the release of insulin by incubated islets of O. tau. The leucine effect appeared to be enhanced by the simultaneous addition of glucose (40 mg/100 ml) to the incubation medium. Arginine (1 mg/ml) had no effect upon the release of insulin in vitro. The significance of the results is discussed.

THE ACTIVITY OF URIDINE DIPHOSPHATE GLUCOSE-GLYCOGEN SYNTHETASE IN SOME EMBRYONIC TISSUES

Uridine diphosphate glucose (UDPG)-glycogen synthetase has been studied using chemical and histochemical methods. Activity was demonstrated in whole egg and in homogenates of whole 3-day old chick embryos, in the heart and skeletal muscle from the 5th day and in the liver from the 7th day of incubation onwards. The activity increases with age until the 16th day at which time a sharp fall was noted in all tissues studied. Enzyme activity was demonstrated also in heart, liver, skeletal muscle and brain of rat embryos from the 14th day onwards. In these tissues the activity increases with age until birth. The appearance of UDPG-glycogen synthetase in the tissues of the chick embryo coincides with the time at which, according to previously published data, glycogen begins to appear. In the liver of the rat embryo, the enzyme appears before glycogen formation starts. This is contrary to the behavior of phosphorylase which appears later, at least in skeletal muscle. These findings are in agreement with the view that, in vivo, glycogen synthesis occurs via the UDPG, rather than the phosphorylase, pathway.

Serum Insulin Concentration and Birth Weight in Human Infants.

Summary Serum immuno-reactive insulin (IRI) and glucose levels were measured in the blood of newborn infants and of their mothers. Infants weighing more than 4 kg at birth were found to have significantly higher serum IRI values than infants of “normal” weight. No statistically significant correlations were found between infant and maternal serum IRI and their respective fasting blood glucose concentrations.

DEVELOPMENT OF PHOSPHORYLASE AND PHOSPHORYLASE-ACTIVATING (GLUCAGON-LIKE) SUBSTANCES IN THE RAT EMBRYO.

Abstract Phosphorylase and phosphorylase-activating substances (glucagon-like activity or GLA) were measured in the tissues of rat embryo at various stages of development. Hepatic phosphorylase activity increases up to the 18th day of gestation, at which time it reaches values comparable to those found in the liver of newborn and adult rats. Glucagon-like activity may be detected in the tissues of the embryo on or about the 14th day of gestation. Between the 18th and 19th day, pancreatic GLA reaches values comparable to those found in the pancreas of newborn and adult animals. The results suggest that enzyme and enzyme-stimulating activity develop in a parallel fashion and reach a maximum shortly before birth, at a time when, according to other studies, hepatic glycogen concentration decreases to relatively low values.

Blood vessel disease in diabetes mellitus

When, on November 14, 1921, Banting and Best communicated the discovery of insulin to the University of Toronto Physiological Journal Club and to the world, not only did they solve a riddle which had puzzled humanity for millenia, but by saving the lives of millions of diabetics, they unwittingly created new problems. Thanks to insulin, millions of diabetics reached maturity, pregnancies were saved and the diabetic genes began to spread to an every increasing number of people, more and more patients reached the age of complications, creating a public health problem of pandemic proportions. Thus, it was altogether fitting that the V Capri Conference, held on the 50th anniversary of the discovery of insulin, be entitled Blood Vessel Disease in Diabetes Mellitus.

Adenosine Triphosphate-Hexose Phosphotransferase in Developing Chick Embryo Heart.∗

Summary Determinations of ATP-hexose phosphotransferase activity in chick embryo hearts demonstrated the presence of a soluble hexokinase. The enzyme has a low Km for glucose, a maximum activity at pH 8.0–8.5 and is inhibited by glucose-6-phosphate. Total enzyme activity does not change between the 5th and 7th day of development, decreases moderately thereafter and increases after hatching. The slight reduction of total enzyme activity observed between the 5th and 10th day of embryologic development is inadequate to account for the previously reported decrease in the maximal rate of intracellular glucose phosphorylation occurring in intact hearts during the same period.

Development of Hepatic Phosphorylase in the Chick Embryo.

Summary Phosphorylase activity was measured in the liver of chick embryos at various stages of development. Enzyme activity increases abruptly between the 16th and 18th day of incubation, at a time when, according to previous studies, hepatic glycogen concentration and UDPG-glycogen transfer-ase activity decrease to relatively low values.

The Fourth International Congress of Endocrinology (Washington, June 18–24, 1972)

The Fourth International Congress oB Endocrinology was held in Washington, on June 18-24, 1972. It was a large meeting with 5 plenary lectures, 49 symposia, 57 short communications sessions and 7 workshops. Diversion from this intense scientific work was provided by many public and private receptions, by a special tour and concert at the National Gallery of Art, a concert at the Kennedy Center for the Performing Arts, several tours of the city and of the surrounding areas, and finally, by the violence of hurricane Agnes that hit Washington with strong winds and torrential rains, flooding many parts of the city. On June 32rd many participants attended a memorial service for Dr. Solomon A. Berson, where seven of his many /riends and co,workers spoke briefly and in moving terms about the greatness of this man who was equally at home in the fie!ds of music and philosophy as in the fields oB mathematics and science. Predictably there were many papers dealing with the relationships between hormones and cyclic AMP. R.J. Ho (U.S.A.) spoke on the feedback regulation of cyclic AMP production in adipocytes isolated /rom rat epididymal rat pad. When these cells were stimulated with epinephrine, the production of cyclic AMP creased after reaching a maximum, but when the adipocytes were transferred to a new incubation medium, the production of nueleotide started again. Apparently the production of cyclic AMP was accompanied by the liberation oB an inhibiting substanee which accumulated in the me-

32nd Annual Meeting of the American Diabetes Association (Washington, June 23–25- 1972)

The 32nd Annual Meeting of the American Diabetes Association was held in Washington, on June 23, 24 and 25, 1972, immediately following the IVth International Congress of Endocrinology. Indeed, on Saturday morning, June 24, as the American Diabetes Association was holding a symposium to commemorate the fiftieth anniversary of the discovery of insulin, the Congress of Endocrinology was holding its final workshops. For many participants who attended both congresses, lasting a total of eight days, it was a very rewarding, even if an exhausting experience. The activities started on the evening of June 23 when members of the American Diabetes Association and the publie united in a tribute to Dr. and Mrs. Charles H. Best and to Lady Banting, widow oB the late Sir Frederick Banting. Master of Ceremonies was William F. Talbert, a diabetic international tennis star. Tributes were read by Mrs. Gail Patrick Jackson, speaking for the world of television, by Mr. Talbert, speaking for the world of sports, by Pastor O. Gibson, speaking for the world oB religion, by Mrs. Lynn Hoover, mother of a diabetic child and by Michael F. Kaufman, a young diabetic. During the evening, awards were given to Dr. Walter R. Campbell, who administered the first dose of insulin to a diabetic patient, to Dr. Dorothy C.

International Conference on the Physiology and Pharmacology of Cyclic AMP

More than four hundred scientists representing 27 different countries gathered in Milano on July 20-23, 1971 to artend the International Conference on the Physiology and Pharmacology of Cyclic AMP, one of the satellite symposia of the 25th International Congress of the Physiological Sciences. The conference was organized by Professor Rodol/o Paoletti (Milano) and G.A. Robison (Nashville), under the joint sponsorship of the University of `Milano, the International Society for Biochemical Pharmacology and the Stare University of New York at Buffalo. Honorary Chairman was Earl W. Sutherland, Professor of Physiology at Vanderbilt University in Nashville who, a few months later, was to receive the 197I Nobel Prize for Physiology and `Medicine, for bis discoveries concerning the biologic role of cyclic A`MP. The symposium consisted of approximately 60 lectures and 75 communications, illustrating the universal role of cyclic A`MP (cA,MP) as a chemical messenger, not only in mammals and in other vertebrates, hut also in molds, in bacteria, and in cultures of tumor cells. Dr. Emilio Trabucchi welcomed the participants in the name of the Rettore Magnifico oB the University of `Milano and Dr. J.F. DANIELLI (Buffalo) replied for the participants. Properly, the first lecture was delivered by