Virgilio G. Foglia

Fatal Loss of Plasma Volume After Lymph Heart Destruction in Toads

Conclusions Toads without lymph hearts kept in constant humidity showed no change in body weight, whereas other animals kept in the presence of water showed a gain in weight of as much as 20% daily. With a constant body weight the fluid redistribution can be assumed to be internal. In both series of experiments there was a marked increase in red call volume to a point where flow even in large vessels was impeded. The fall in plasma and lymph protein, and the rise in body fluid, potassium content and tissue water are much greater when water is absorbed through the skin by contact. When the normal flow of fluid from plasma to tissue space to lymph channels to vascular system is blocked by lymph heart destruction, there is a marked increase in the interstitial fluid at the expense of the plasma. The failure of this edema fluid to return to the blood vessels in these experiments is a primary and uncomplicated cause of death.

Aortic Mucopolysaccharides in Experimental Diabetes

The effect of experimental diabetes, produced by 95 per cent pancreatectomy, on the synthesis and concentration of specific mucopolysaccharide fractions in rat aortas was studied. Animals were sacrificed three and six months after pancreatectomy, and the findings were significantly different at the different times. It was found that at three months, when blood sugar levels were only minimally elevated, the concentrations of chondroitin-4-sulfate, chondroitin-6-sulfate and dermatan sulfate-containing fractions were markedly increased, whereas six months after panereatectomy the concentrations of the chondroitin-4-sulfate and chondroitin-6-sulfate-containing fractions were lower than normal. The increase in these fractions at three months is ascribed to both increased synthesis and decreased degradation. At six months, concomitant with the rise in blood sugar, the metabolic pattern was reversed and there was decreased synthesis and increased degradation of these substances.

Periodontal Changes and Dental Caries in Experimental Prediabetes

The prevalence, activity and rate of progression of dental caries, as well as the periodontal histopathology (presence or absence of pathological pockets, structure and thickness of the osseous alveolar crest, and width of the marginal periodontal ligament) in prediabetic and diabetic white rats were studied. The observations of caries activity (within the prediabetic period) were made on rats sacrificed forty-five days after being 95 per cent and 80 per cent pancreatectomized. A significant increment of caries activity was found in all aspects investigated in both groups of experimental animals with respect to normal and sham operated controls. The histopathology of the periodontium of 95 per cent pancreatectomized rats sacrificed ten months after the operation with diabetes of several months and varying degrees of hyperglycemia showed morphological alterations of the osseous alveolar crest, with significant thickening of the marginal periodontal ligament. This process could be observed very early in prediabetes in rats with normal blood sugar, no glycosuria, and normal diuresis and body weight, sacrificed three months after the operation. Even though it seems to be indisputable that alterations of carbohydrate metabolism in diabetic rats have an aggravating effect, changes in prediabetes suggest that the observed caries and lesions of the periodontium start very early and independently of the diabetic changes in carbohydrate metabolism.

Dental Caries in Diabetic and Prediabetic Rats

SYNOPSIS IN INTERLINGUA CARIE DENTAL IN RATTOs DiABETic E PREDIABETIC.—Le prevalentia, incidentia, e rapiditate evolutive de carie dental esseva studiate a base de un registration del numero de afficite e destruite dentes molar e de cavitates, si ben como del typo de carie incontrate. Un convenibile indice esseva applicate pro exprimer le grado de susceptibilitate. Statos diabetic e prediabetic esseva provocate per pancreatectomia a 95 pro cento, controlate per determinationes periodic del sucro sanguinee in stato jejun. Le condition diabetic accelerava notabilemente le establite processo de carie. Un augmento significative in le prevalentia, le incidentia, e le rapiditate evolutive esseva observate non solmente in animales con confirmate e incipiente diabete sed precocemente etiam in animales prediabetic.

Phosphorylation, oxidation, and ubiquinone content in diabetic mitochondria.

Summary Respiratory and phosphorylat-ing activities were determined in liver mitochondria from mild and severely diabetic rats. Diabetes was caused by 95% pancreatectomy performed 6-18 months before the investigation of mitochondrial function. Diabetic mitochondria showed depressed respiratory rates with β-hydroxybutyrate, L-malate-L-glutamate, and succinate as substrates while the P:O ratios did not depart from the normal control values, with all the employed substrates. Ubiquinone levels were significantly increased in mitochondria from severely diabetic rats while cytochrome c and mitochondrial protein remained unchanged.

Action of sex hormones on the insulinemia of castrated female rats.

Summary Castrated female rats received daily subcutaneous injections of progesterone (500 μg/day), testosterone (500 μg/day), and 17 β-estradiol (4 μg/day) for 7 months. Lower fasting blood sugar values were found in the 17 β-estradiol-treated group after 6 and 7 months of treatment. The plasma immunoreactive insulin level was augmented by the sixth month of treatment in the testosterone treated group and by the second, fifth, sixth, and seventh months of treatment in the 17 β-estradiol group.

Metabolic Sensitivity of Different Hypothalamic Areas to Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH), and Testosterone

In the present paper, the effect of administration of FSH, LH, and testosterone on the oxidative metabolism of the anterior, middle, and posterior hypothalamus of hypophysectomized-castrated rats was studied. FSH produced a significant depression of the oxidative activity in the posterior hypothalamus without modifications in the other hypothalamic areas. On the other hand, LH depressed the metabolic activity only in the anterior hypothalamus. Testosterone produced an effect similar to that of LH, i.e., a decrease in the oxygen uptake of the anterior hypothalamus without modifications in the respiration of the middle and posterior hypothalamus. The relationship between these findings and the short feed-back mechanism controlling FSH and LH secretion is discussed.

Effect of hypophysectomy on the oxidative and glycolytic metabolism of hypothalamus

En el presente trabajo se ha estudiado el consumo de oxígeno y la producción de ácido láctico en hipotálamo anterior, medio y posterior en animales hipofisectomizados. Los resultados obtenidos indicaron que la hipofisectomía produce un significativo incremento en la actividad oxidativa del hipotálamo anterior y posterior sin modificar el hipotálamo medio.

Effect of estrogens on blood sugar, serum insulin and serum free fatty acids, and pancreas cytology in female dogs

SummaryWe analyzed the changes in blood sugar (BS), serum immunoreactive insulin (IRI), circulating free fatty acids (FFA) and pancreatic cytology caused by estrogenization at low pharmacological dosage in female dogs. Vehicle-injected and untreated controls (anestrus) were studied as well. Neither mean basal BS nor basal serum IRI was modified by the treatments, while the mean basal serum FFA value was raised. Glucose tolerance was not modified by the estrogens while glucosey-mean was significantly raised. Hyperglycemia was higher for a longer time in estrogenized animals compared to both controls, while the profiles of hyperinsulinemia coincided. In the estrogen-treated bitches, the pancreatic B-cells contained scarse brown-stained granules near their vascular pole, as shown by an immunochemical method. In the peripheral part of the pancreas, near the acini, some solitary, poorly β-granulated B-cells were present. During the IVGTT, serum FFA reached lower values for a longer time in the estrogenized bitches as compared to those found in both control groups. Insulin-induced hypoglycemia in the estrogenized animals coincided with the one evoked in the vehicle controls; in the semilog relationship of serum IRI and time,y-mean was lower than that observed in oil-injected controls, and insulin space was larger. The serum FFA levels of the estrogenized bitches, very high in the basal conditions, did not respond to insulin administration, and were above those found in untreated controls and also in vehicle-injected controls just at the beginning of the test. These results are discussed. We came to the conclusion that estrogenization causes some glucose intolerance in bitches while insulin sensitivity remains normal in the IVITT as studied measuring BS. The glucose intolerance is thought to be related to a reduction in glucose space and occurs despite the normality of the serum IRI response. The pancreas must have an intense secretory responsein vivo so as to maintain normal IRI activity despite degranulation of the islets of Langerhans and poor islet hypertrophy and neoformation. The serum FFA changes are thought to contribute towards the tendency to adiposity in these animals.

Studies on carbohydrate metabolism in penguins (Pygocellis papua)

Abstract The present experiment was performed in the Antartic continent at 64° 53′ S Lat; 62° 53′ W Long. Gento penguins ( Pygocellis papua ) were studied after 24–48 hr and 6–12 days of starvation. After intravenous injection of glucose (1 g/kg), the blood sugar levels remained elevated for periods up to 10 hr. Starvation did not affect the glucose tolerance curve. The pancreatic function was tested using hipoglycemic agents. Tolbutamide (200 mg/kg) and chlorpropamide (100 mg/kg) did not induce any changes in the blood sugar level. Inmunoreactive serum insulin level was about 40 μU/ml after 24–48 hr of starvation. This value fell to about 10 μU/ml after 12 days of starvation. Intravenous glucose injection was without significant effect in insulin secretion.