Presence of sodium transport inhibiting factor in dog plasma during volume expansion.

Plasma dialysates from volume-expanded dogs (E) were compared directly to dialysates from the same dogs when hydropenic. In a double-blind study, E caused relative inhibition of short-circuit current in toad urinary bladder. We therefore confirm the presence of a sodium transport inhibiting factor in plasma of volume-expanded dogs.     

Tolerance to cold and glucose homeostasis in adrenal demedullated dogs

Summary The rise in O₂ consumption and in glucose turnover, induced by acute cold exposure is not suppressed by adrenal demedullation in dogs. However, both at neutral and cold ambient temperature, the mean plasma glucose concentrations are higher in normal (N) than in adrenal-demedullated dogs (ADMX). In the cold, the fall in rectal temperature is larger in ADMX than in N dogs.This work was supported by a grant from Université Claude Bernard (U.E.R. Lyon Nord and U.E.R. Biologie Humaine).The authors thank D. Rougier and G. Dallevet for their excellent technical assistance and A. Brillant for secreterial assistance.     

Hematocrit as an index of changes in plasma volume in conscious dogs

Summary Hematocrit (HCT) measurements were made in intact and splenectomized conscious dogs to determine if observed decreases in HCT were produced by plasma volume expansion or splenic sequestration of erythrocytes. We found that in conscious dogs HCT is a poor indicator of changes in plasma volume.Supported by National Institutes of Health grant No. HL 13427.I.Z. ist the recipient of an Established Investigator Award from the American Heart Association.Acknowledgment. The authors wish to thank Mary Anne Richards for her technical assistance.     

Inhibition or augmentation of PHA-induced lymphocyte transformation by factors of cultured lymphoblastoid cell lines

Summary Stimulation of human peripheral blood lymphocytes by phytohemagglutinin (PHA) was found to be suppressed or augmented by the addition of supernatants or cell dialysates of cultured lymphoblastoid cell lines.This research was supported by a grant from the United States-Israel Binational Science Foundation (BSF), Jerusalem, Israel.We wish to thank Mrs L. Ashani and Mrs D. Bernhout-Maiberger for their valuable technical assistance.     

Effect of epinephrine upon irreversible disposal and recycling of glucose in dogs

Summary Irreversible utilization and recycling of glucose during epinephrine-induced hyperglycemia were studied in adrenal-demedullated dogs exposed to neutral or cold ambient temperature. Whatever the ambient temperature, most of the extra glucose mobilized by epinephrine is recycled rather than irreversibly utilized by the peripheral tissues.This work was supported by a grant from Université Claude Bernard (U.E.R. Lyon Nord and U.E.R. Biologie Humaine).J. Schellhorn was on leave from the University of Chile. The authors thank D. Rougier and G. Dallevet for their excellent technical assistance.     

Effects of sequential periods of intracranial hypertension on lung fluid balance

Summary Pulmonary hemodynamics and fluid and protein exchange were examined in dogs subjected to three successive periods of intracranial hypertension. Results indicate that the alteration in lung fluid balance is due to increased microvascular surface area following capillary recruitment. The relationship to the mechanism of neurogenic pulmonary edema is discussed.Acknowledgments. Supported in part by grants 79-N17, 80-N105 and 82-N136 from the California Affiliate of the American Heart Association, by a grant from the Strobel Medical Research fund of the American Lung Association of San Francisco and by USPHS GMO7416-2 traineeship (TAJ). The authors thank L. Blount, E. Blount and J. Wong for their assistance.     

Presence of oncornavirus-like particles in the P388 murine leukemic cell line

Summary A culture of P388 murine lymphoblastoid cells has been shown to contain type C oncornavirus-like particles budding at the plasma membrane. Occasionally intracytoplasmic type A and immature type B particles were also observed by electron microscope techniques. The discovery of oncornavirus-like particles in the P388 cell line increases the utility of this neoplastic system for detecting potential antineoplastic agents.Supported by Contract NO1-CM-67048 from the Division of Cancer Treatment (DCT), National Cancer Institute (NCI), National Institutes of Health, Department of Health, Education, and Welfare. The fannie E. Rippel Foundation, Talley Industries, and the Phoenix Coca Cola Bottling Co. We are also grateful to Miss Linda M. Lange for technical assistance.     

Hematocrit as an index of changes in plasma volume in conscious dogs.

Hematocrit (HCT) measurements were made in intact and splenectomized conscious dogs to determine if observed decreases in HCT were produced by plasma volume expansion or splenic sequestration of erythrocytes. We found that in conscious dogs HCT is a poor indicator of changes in plasma volume.     

Determination of acetaldehyde in human blood

Summary A method for the determination of acetaldehyde in human plasma by headspace gas chromatography is described. Chloralhydrate, an inhibitor of aldehyde dehydrogenase, is immediately added to the blood sample to prevent a rapid disappearance of acetaldehyde in the erythrocytes.This work was supported by the Swiss National Science Foundation.The authors thank Miss Ch. Coullery and Miss E. Ernst for their technical assistance.     

Bradykinin-induced stimulation of cardiac parasympathetic ganglia

Summary Bradykinin slows the heart rate of the rabbit isolated heart. It appears to act as a non-nicotine-like stimulant on the cardiac parasympathetic ganglia.We thank Miss L. Späth and Mr E. Schöffel for skilled technical assistance. This study was supported by the Deutsche Forschungsgemeinschaft.     

Effect of ambient cold on urine concentration by the intact and denervated dog kidney

Summary In dogs transferred from room temperature to a low temperature of 1±(SD) 3.5°C, the plasma norepinephrine (NE) level increased significantly. Urine concentration decreased in the cold, in the intact and similarly in the chronically denervated kidney. After return to a warm environment urine concentration improved in both kidneys while plasma NE remained elevated. The data speak against an essential role of the renal nerves in the adaptation of renal function to ambient cold.Acknowledgments. We are greatly indebted to Dr J. Kurkus and Dr R. Gellert who performed the operations of surgical bladder division, and to Mrs W. Radziszewska for determination of plasma norepinephrine. The study was supported within the national research problem No. 10.4.     

Effects of anaesthesia and chronic catheterization on circulating levels of prostaglandins (PGE2 and PGF2a in dogs

Summary Chronic catheterization of aorta and inferior vena cava in dogs did not significantly affect circulating levels of prostaglandins (PGE₂ and PGF_2a ). Pentobarbital (30 mg/kg i.v.) anaesthesia produced a significant decrease in PGF_2a .This work was supported by INSERM (grant No. 76.5.183.5).We wish to thank Miss Laure Eloy and Mrs Annick Soubrier for their technical assistance.     

Microspectrography of formaldehyde and fluorescamine-induced fluorescence in rabbit pulmonary neuroepithelial bodies: Demonstration of a new,probably polypeptide intracytoplasmic substance

Summary The microspectrographic analysis of the fluorescence emitted by NEB's in gaseous formaldehyde-fixed lung tissue, posttreated with fluorescamine, revealed the presence of numerous primary amino groups which are clearly different from the serotonin identified in our earlier studies and correspond to a new, probably a polypeptide intracytoplasmic substance.Supported by a grant from the Council for Tobacco Research (USA) and the National Fonds voor Wetenschappelijk Onderzoek (Belgium). We thank C. Armee, M.-R. Van Hamme and E. Swinnen for technical, G. Pison for photographical and N. Tyberghien for secretarial assistance.     

Gene activity int eh carnation-light synthetic lethal inDrosophila melanogaster

Summary A gynandromorphic study of the carnation-light synthetic lethal revealed a site of lethal interaction (focus) in nerve tissue. Because both the carnation and light loci are known to be active in non-nervous tissue we have interpreted our results in terms of a model which accounts for diminution of developmental potential as a result of irreversible gene repression rather than selective gene activation.We thank Dr J. Flanagan for providing his computerized focusing programs and Fr. E. Sharp for providing assistance in the writing of related computer programs. This research was supported by Research Corporation.     

Effect of hyperkalemia on insulin secretion

Summary The effect of hyperkalemia on insulin secretion remains undefined. We evaluated portal and peripheral insulin levels in anesthetized dogs after infusions of KCl. The mean maximal increase in peripheral plasma potassium at infusion rates of 0.2 mEq/kg/h was 0.68±0.20 mEq/l. There were no significant increases in either portal or peripheral insulin levels. In contrast, in six dogs whose plasma potassium concentration increased in each case by more than 2.0 mEq/l (infusion rate of 0.5 mEq/kg/h), portal insulin levels increased fivefold (p<0.05). We conclude that only marked increases in plasma potassium concentration stimulate pancreatic insulin secretion.     

Effect of hyperkalemia on insulin secretion

The effect of hyperkalemia on insulin secretion remains undefined. We evaluated portal and peripheral insulin levels in anesthetized dogs after infusions of KCl. The mean maximal increase in peripheral plasma potassium at infusion rates of 0.2 mEq/kg/h was 0.68 +/- 0.20 mEq/l. There were no significant increases in either portal or peripheral insulin levels. In contrast, in six dogs whose plasma potassium concentration increased in each case by more than 2.0 mEq/l (infusion rate of 0.5 mEq/kg/h), portal insulin levels increased fivefold (p less than 0.05). We concluded that only marked increases in plasma potassium concentration stimulate pancreatic insulin secretion.     

Effects of intracerebroventricular injections of angiotensin II on prolactin plasma levels in the Rhesus monkey

Summary Intracerebroventricular injections of angiotensin II (A II) induced a sharp and dose-dependent increase in plasma prolactin (PRL) levels in the awake Rhesus monkey. Our results suggest that in primates, A II may be involved in the mechanisms controlling PRL secretion.Acknowledgments. We thank Mrs. J. Arsaut and D. Verrier for excellent technical assistance. This work was supported by grants from INSERM (CRL No. 78.1.2656), DGRST (77.7.9654) and CNRS (ERA 493).     

Enrichment of CO2 and magnesium in early stages of biomineralization

Summary Simultaneous topochemical analyses of calcium, magnesium, carbonate (as CO₂) and phosphorus in a mineralizing collagen rich system (turkey tibia tendon) showed a strong enrichment of Mg and CO₂ in the prestages of biomineralization.We thank the Deutsche Forschungsgemeinschaft for support and Mr E. Kalthoff for assistance.     

Endurance training and antioxidants of lung

Summary Mice and rats were adjusted to daily treadmill training programs, which were heavy enough to increase the oxidative capacity of skeletal muscles. Endurance training did not affect the activities of catalase and glutathione peroxidase and the concentration of vitamin E in the lungs of mice and rats. Thus increased ventilation and oxygen utilization induced by exercise training do not modify lung antioxidants, in contrast to hyperoxia and hypoxia.This study was supported by the Academy of Finland and the Research Council for Physical Education and Sport (Ministry of Education, Finland). We thank Mr Matti Virtanen for skillful technical assistance.     

A centrally induced vasodepressor response after intravenous administration of whole venom ofNaja mossambica pallida in cats

Summary Naja mossambica pallida venom administered i.v. (300 /kg) produces an initial brief fall in blood pressure, due to a direct myocardial depressant effect, and a sustained fall due to central depressant effect.This study was supported by University of Nairobi research grants (670–376). We also thank Mr E. Njogu for photographic assistance.