bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of arginine vasopressin on cerebral microvascular pressure
Authors: Faraci F. M. , Mayhan W. G. , Schmid P. G. , Heistad D. D.
Published: December 2017

The goal of this study was to examine effects of arginine vasopressin and angiotensin on cerebral microvascular pressure and segmental vascular resistance. We measured pressure (servo-null) in pial arteries that were approximately 200 micron in diameter and cerebral blood flow (microspheres) in anesthetized cats, and we calculated resistance of large and small cerebral vessels. Resistance of large arteries (greater than 200 micron diam) was approximately 45% of total cerebral vascular resistance under control conditions. Vasopressin (40 mU/kg iv) decreased resistance of large arteries by 22 +/- 7%, increased pial artery pressure by 10 +/- 2 mmHg when aortic pressure was maintained at control levels, and increased small vessel resistance by 27 +/- 11%. This increase in small vessel resistance apparently was an autoregulatory response to the increase in pial pressure. Cerebral blood flow was not changed (38 +/- 4 vs. 37 +/- 3 ml.min-1.100 g-1). Intravenous infusion of angiotensin (2 micrograms.kg-1.min-1) increased large artery resistance by 32 +/- 6%, decreased pial artery pressure 6 +/- 3 mmHg with aortic pressure maintained constant, and decreased cerebral blood flow by 12 +/- 1%. Thus circulating vasopressin, at concentrations similar to those observed during hemorrhage, selectively dilates large cerebral arteries and increases microvascular pressure without changes in cerebral blood flow. In contrast to vasopressin, angiotensin selectively increases resistance of large cerebral arteries and decreases cerebral microvascular pressure. Thus vasopressin and angiotensin, at doses that have minimal effects on cerebral blood flow, may play an important role in regulation of cerebral microvascular pressure.
THE FLOW OF LYMPH FROM THE LUNGS OF THE DOG
Authors: Warren Madeleine F. , Drinker Cecil K.
Published: December 2017

Volume 136: No. 1, p. 207, 1941. M. F. Warren and C. K. Drinker, The Flow of Lymph from the Lungs of the Dog.

P. 208, change (Drinker et al., 1941) to (Drinker et al., 1940). P. 213, change Maurer (1941) to Maurer (1940). P. 221, insert the following references in the bibliography: Drinker, C. K., M. F. Warren, F. W. Maurer and J. D. McCarrell. This Journal 130: 43, 1940. Maurer, F. W. This Journal 131: 331, 1940.
COMBINATION OF EVANS BLUE WITH PLASMA PROTEIN: ITS SIGNIFICANCE IN CAPILLARY PERMEABILITY STUDIES, BLOOD DYE DISAPPEARANCE CURVES, AND ITS USE AS A PROTEIN TAG
Authors: LeVeen Harry H. , Fishman William H.
Published: December 2017

Volume 151, page 30, lines 4 and 6. The dissociation constant should read 2 x 10–6 instead of 2 x 10–3.
CORONARY SINUS CATHETERIZATION FOR STUDYING CORONARY BLOOD FLOW AND MYOCARDIAL METABOLISM
Authors: Goodale Walter T. , Lubin Martin , Eckenhoff James E. , Hafkenschiel Joseph H. , Banfield William G.
Published: December 2017

Volume 152, page 340. Under table 2, top, right-hand column, "coronary, mean ±σm", the first entry should read: 13.0 ± .54 instead of 13.0 ± 5.4.
RÔLE OF THE HERRING-BREUR REFLEX UNDER DEEP PENTOTHAL ANESTHESIA
Authors: Scott J. C. , Reed E. A. , Saris D. , Ramirez H. P. Redondo
Published: December 2017

Volume 154, page 428. In title and throughout text, "Herring-Breur" should read "Hering-Breuer".
CORONARY BLOOD FLOW AND CARDIAC OXYGEN CONSUMPTION IN UNANESTHETIZED DOGS
Authors: Spencer F. C. , Merrill D. L. , Powers S. R. , Bing R. J.
Published: December 2017

Page 149: Footnote 1 should read, "This work was supported by grants from the Commonwealth Fund, from the National Heart Institute, Public Health Service, and from the Carolyn Rose Strauss Foundation, Inc., given to the Department of Surgery, The Johns Hopkins Hospital."
Cardiovascular function in nonarteriosclerotic versus arteriosclerotic rats
Authors: Colfer HT , Iams SG , Wexler BC
Published: December 2017

Cardiovascular function of arteriosclerotic (breeders) and nonarteriosclerotic (virgins) male am exercise was examined in the denervated gracilis muscle of the anesthetized dog. The data show that 1) on initiation of heavy exercise, the effluent blood PO2 and pH fall markedly and then rise slowly but remain depressed relative to control during 60 min of exercise hyperemia, while the initial increases in [K+] and osmolality rapidly approach and eventually reach preexercise levels. 2) The enhanced vasodilator activity of venous blood from exercising muscle is attenuated when effluent blood PO2 or pH is corrected to preexercise levels; it is completely abolished when both are corrected. 3) Induced reduction of PO2 or pH in the arterial inflow, and thus venous outflow, of resting muscle produces a fall in resistance; simultaneous reductions of both to levels seen in heavy exercise produce a fally in resistance to near that observed during exercise. Since the enhanced vasodilator activity of venous blood from the contracting muscle was abolished by simultaneous correction of the PO2 and pH, it seems likely that these factors, acting directly or indirectly, are the prinicipal chemicals responsible for the maintenance of the vasodilation seen in canine skeletal muscle during heavy exercise.
Quantitative relationship of renal glucose and sodium reabsorption during ECF expansion
Authors: Higgins JT  , Meinders AE
Published: December 2017

To investigate the quantitative relationship between glucose and sodium reabsorption during extracellular fluid (ECF) expansion and to examine the possible contribution to glucosuria of passive diffusion of glucose from peritubular blood to tubular fluid, renal clearance studies were carried out in dogs. It was found that ECF expansion with isotonic saline or Ringer solution causes a decrease in the maximal rate of glucose reabsorption (TmGlc), which is inversely and linearly related to fractional sodium excretion (FENa) over a range from less than 1% more than 25% FENa (r equals -0.394, P less than 0.001). A continuous relationship between TmGlc and FENa could be demonstrated as the ECF was expanded in individual animals as well as in pooled data. Infusion of albumin solution to preferentially expand the plasma volume and decrease proximal tubular sodium reabsorption produced a 24% fall in TmGlc suggesting that the proximal tubule is the site of interrelated glucose and sodium reabsorption. After pulse injections into the renal artery, [14-C]glucose and insulin had the same appearance time in the urine, thus failing to demonstrate diffusion of glucose from blood into the tubule in saline-loaded dogs as well as in dogs in normal sodium balance. It is suggested that ECF expansion exerts its effect on glucose reabsorption by inhibiting the coupled transport of glucose and sodium across the epithelium of the renal proximal tubule.
Osmotically induced changes in electrical resistance of distal tubules of rat kidney
Authors: de Bermudez L , Windhager EE
Published: December 2017

Changes in peritubular oncotic pressure do not alter the electrical resistance of distal convoluted tubules. Transverse specific electrical resistance decreases along the distal convoluted tubule in nondiuretic rats. This drop in resistance can be at least in part accounted for by the relative increae in osmolality of late distal fluid. Osmotic gradients influence the magnitude of intercellular rather than transcellular conductance. Hyposmolality of tubular fluid leads to reduced shunting, whereas increased tubular osmolality has the opposite effect. The osmotic effect forms part of an intraepithelial positive feedback loop for sodium reabsorption in the diluting segment of the renal nephron.
Effect of antilymphocyte serum (ALS) on shock in rats
Authors: Ringle DA , Herndon BL
Published: December 2017

Effects of treatment with rabbit antirat anti-lymphocyte serum and globulin (ALS and ALG) on shock survival were studied in Sprague-Dawley derived male rats. Because of their known cytotoxic capability, it was postulated that lymphocytes might play a role in the pathogenesis of shock and that suppression of lymphocyte function by ALS/ALG treatment should then protect against shock. Shock models used were tourniquet, endotoxin, and hemorrhagic shock. Protection against tourniquet shock was found for ALS made against thymocytes but not for ALS against spleen cells or lymph node cells. The shock-protective factor was found in the ALG-containing serum fraction but not in the primarily albumin fraction. No significant protection was found for ALS treatment against either endotoxin or hemorrhagic shock. ALS effects on blood cell counts, reticulo endothelial system clearance, and inflammation were studied to help identify effects of ALS on shock survival. It was concluded from these studies that thymic or thymus-processed lymphocytes could play a role in the pathogenesis of shock but that multiple effects of ALS/ALG treatment necessitate further studies to elucidate any role for lymphocytes in shock.
Control of energy metabolism in fish white muscle
Authors: Driedzic WR , Hochachka PW
Published: December 2017

Concentrations of key metabolites were determined in carp white muscle before exercise and after maximal activity. It was found that the concentration of ATP decreases by about 65%, ADP decreases slightly, and AMP remains unchanged. Consequently, the level of the free adenylate pool decreases. Simultaneously there is an increase in the concentration of IMP and NH4+. The increase in IMP level and the decrease in adenylate pool are essentially in 1:1 stoichiometry, a result showing that the adenylate pool is decreased by the reaction catalyzed by 5'-AMP deaminase (EC 3.5.4.6 .). During exercise there is an increase in levels of glucose-6-phosphate, fructose 6-phosphate, and fructose 1,6-diphosphate that, along with the decrease in ATP levels, can account for the increase in glycolytic flux by activation of phosphofructokinase and pyruvate kinase.
Oxygen uptake for negative work, stretching contractions by in situ dog skeletal muscle
Authors: Stainsby WN
Published: December 2017

Oxygen uptake for negative work, stretching twitch contractions by in situ gastrocnemius-plantaris muscle was calculated from measurements of venous outflow and arterial and venous blood oxygen contents. Contractions were produced by valving air at high pressure into the pneumatic lever 10-50 ms before stimulation of the muscle. The loads produced were up to about 2.5 times isometric. Muscle length was always below optimal isometric length. Oxygen uptake for shortening contractions increased with increasing load up to isometric load. Oxygen uptake for stretching contractions decreased with increasing loads above isometric load. Velocity of shortening decreased with increasing loads up to isometric load whereas velocity of stretching increased with increasing loads above isometric. In shortening contractions external work done by the muscle was greatest at intermediate loads, but in stretching contractions the work done on the muscle increased with increasing loads. In stretching contractions the ratio of the energy equivalent of the work absorbed by the muscle reached 8.0 times the energy equivalent of the oxygen uptake. Since this ratio cannot exceed 1.0 for an engine, muscles must act as brakes during stretching contractions.
Cardiovascular responses to electrocardiogram-coupled stimulation of rabbit aortic nerve
Authors: Stinnett HO , Peterson DF , Bishop VS
Published: December 2017

Electrical stimulation of the rabbit's aortic nerve during one or more cardiac cycles resulted in a reflex fall in heart rate and mean arterial blood pressure (MAP). The onset of bradycardia and of fall in MAP were independent of the number of beats stimulated. The initial slope of the heart rate and MAP responses increased as the number of beats stimulated increased, reaching a maximum at five beats of stimulation. Bradycardia peaked 8 and 10 beats after the end of one and two cycles of stimulation, respectively, while the peak response occurred at, or prior to, the end of stimulation when 12 or more beats were involved. Onset and recovery of both responses were consistent, and seldom did MAP indicate a return toward control during stimulation. Thus, central nervous system modulation of sympathetic activity to the peripheral vasculature was sustained as long as the aortic nerve input was maintained. However, reflex control of heart rate was more complex, involving simultaneous alteration in both vagal and sympathetic efferent activity.
Vitamin K2 absorption by rat everted small intestinal sacs
Authors: Hollander D , Rim E
Published: December 2017

Small intestinal absorption of vitamin K2 was investigated in vitro. Experiments with increasing concentrations of the vitamin up to 900 nM revealed linerity between the concentration and the rate of absorption (r = 0.99). Addition of metabolic uncouplers and inhibitors such as 2,4-dinitrophenol, sodium azide, and potassium cyanide did not decrease the rate of absorption of the vitamin (P less than 0.05). Absorption rate of the vitamin increased when taurocholate was replaced by a nonionic detergent, Pluronic F-68. The addition of butyric and octanoic acids to the incubation solution caused an increase in the absorption rate of vitamin K2. No change in the absorption of the vitamin occurred in the presence of oleic and linoleic acid. Addition to vitamins K1 and K3 to the incubation solution did not change the rate of vitamin K2 absorption. These findings suggest that vitamin K2 is absorbed by the small bowel by a passive noncarrier-mediated diffusion process. The rate of diffusion varied when the lipid and bile salt composition of the incubation solution was modified. Distal intestinal absorption of vitamin K from bacterial sources coupled with colonic absorption of the vitamin may be the major constant source of vitamin K in mammals.
Degradation of prostaglandin E2 and F2alpha by the canine liver
Authors: Anderson FL , Jubiz W , Tsagaris TJ
Published: December 2017

Degradation of prostaglandin E2 (PGE2) and F2 alpha (PGF2 alpha) by the liver was determined in 16 dogs. PGE2 (8 dogs) or PGF2 alpha (8 dogs) was infused into the left ventricle at rates of 3.75, 7.5, 15, 37.5, and 75 mug/min. Blood samples obtained simultaneously from the portal vein (PV), hepatic vein (HV), and abdominal inferior vena cava (IVC) at each infusion rate were tested for PGE or PGF concentration by radioimmunoassy. During PGE2 infusion the mean PGE concentrations in the PV were 0.60, 1.05, 1.40, 2.29, 4.80, and 7.29 ng/ml at each infusion rate, Corresponding concentrations in the HV were 0.51, 0.62, 0.71, 0.96, 1.94, and 2.62 ng/ml, and in the IVC 0.51, 0.95, 1.31, 1.96, 4.31, AND 5;18 NG/ML. During PGF2 alpha infusion, the mean PGF concentrations in the PV were 0.32, 0.59, 0.73, 1.73, 4.11, and 7.11 ng/ml at the respective infusion rates; Corresponding concentrations in the HV were 0.26, 0.24, 0.33, 0.48, 0.49, and 0.96 ng/ml, and in the IVC 0.32, 0.50, 0.61, 1.10, 2.40, and 4.17 ng/ml. Thus, these data indicate that the canine liver has substantial, but not unlimited, capacity for degradation of PGE2 and PGF2 alpha in the portal circulation. Whether or not PGE or PGF levels in the PV may exceed this capacity during periods of stress or whether this enzymatic mechanism may be suppressed by either physiological or pharmacological factors is not known.
Subcellular membrane fatty acids of rat heart after cold acclimation or thyroxine
Authors: Steffen DG , Platner WS
Published: December 2017

Relative percent changes in fatty acid (FA) composition of heart mitochondria and microsomes from 30-day-warm-acclimated and cold-acclimated rats were determined by gas chromatography. Rats in both environmental groups received thyroxine (T4) (1 mg/kg per day) or propylthiouracil (PTU) (5 mg/rat per day) for 10 days prior to sacrifice. Mitochondrial total unsaturated fatty acids (TUFA) decreased in cold-acclimated rats relative to warm-acclimated controls but not in cold-acclimated animals receiving PTU. In mitochondria of the T4-treated warm-acclimated group, the relative content of linoleate decreased and that of stearate increased. Heart microsomes from warm-acclimated rats receiving T4 showed large increases in the percentage content of palmitate and stearate accompanied by reductions in linoleate and arachidonate. In cold-acclimated control rats, the relative content of stearate was elevated in both membrane fractions. The results suggested that thyroid hormones may decrease the TUFA composition of heart subcellular membranes by a relative increase in percent stearic acid and decrease in percent linoleic acid. Similar FA changes in these membranes in cold-acclimated rats may be related to the action of thyroid hormones.
Lung lymph capillary injury-related protease
Authors: Orlowski M. , Lesser M.
Published: December 2017

Capillary damage induced in sheep by intravenous infusion of Escherichia coli endotoxin, oleic acid, or air emboli causes the appearance in lung lymph of a serine protease with trypsin-like activity. The time course of the appearance of the enzyme and the extent of its activity increase indicate a close association with capillary injury. The enzyme was isolated from active lymph after a 9,000-fold purification by affinity chromatography on Reactive Blue-agarose, aprotinin-agarose, and p-amino-benzamidine-agarose columns. The protein, molecular mass of 70-75 kDa, is composed of two polypeptide chains of 31 and 43 kDa linked by disulfide bonds. Studies with synthetic peptide and thioester substrates showed preferential cleavage of substrates having two or more basic amino acids and the importance for activity of secondary enzyme-substrate interactions at sites removed from the scissile bond. The specificity of the enzyme and its pattern of sensitivity to inhibition by a series of isocoumarin derivatives distinguish it from enzymes of the clotting and complement systems and also from tissue plasminogen activator and lung and skin tryptase. The origin of the enzyme, its role in capillary damage, and its physiological function remain to be established.
Alveolar dimensions and number: developmental and hormonal regulation
Authors: Blanco L. N. , Massaro G. D. , Massaro D.
Published: December 2017

We used three-dimensional reconstruction 1) to determine the effect of treating rats with dexamethasone, from age 4 to 13 days, on alveolar volume (v) and number (Na) and 2) to determine if v, Na, or both change between age 14 and 60 days. At age 14 days, v, Na, and gas exchange surface area (Sa) were (2.7 +/- 0.3) x 10(4) microns3, (20.2 +/- 2.1) x 10(6), and 832 +/- 29 cm2, respectively, in diluent-treated rats; in dexamethasone-treated 14-day-old rats the same parameters were (7.5 +/- 1.1) x 10(4) microns3, (9.9 +/- 1.6) x 10(6), and 733 +/- 16 cm2, respectively. At age 60 days, v, Na, and Sa were (7.1 +/- 0.4) x 10(4) microns3, (60.8 +/- 4.1) x 10(6), and 4,495 +/- 187 cm2 in diluent-treated rats and in rats treated with dexamethasone from age 4 to 13 days, v, Na, and Sa at age 60 days were (15.9 +/- 2.4) x 10(4) microns3, (25.8 +/- 3.8) x 10(6), and 3,424 +/- 203 cm2. We conclude that treatment with dexamethasone from age 4 to 13 days (the period of normal septation) resulted in larger alveoli at age 14 and 60 days, and in diluent- and dexamethasone-treated rats the increase in Sa between age 14 and 60 days is due, at least in part, to the formation of new alveoli.
Kinetics of cellular influx and histamine release in normal human bronchi
Authors: Cooper J. A. , Merrill W. W. , Buck M. G.
Published: December 2017

Inhalation of certain substances can induce bronchial inflammation followed by bronchoconstriction or bronchial hyperreactivity. We have developed a model of airway inflammation and bronchoconstriction induced by an aqueous extract of cotton bracts (CBE) in which the severity of flow rate reduction correlates with the presence of bronchoalveolar neutrophils. In the current study normal human volunteers underwent local bronchial instillation of CBE. Bronchial lavage histamine concentrations and cellular populations were determined at time intervals after local challenge. In addition, bronchial biopsies were obtained after CBE instillation, and the degree of subepithelial inflammation was quantitated. We report that lavage of bronchi locally exposed to CBE contains 1) greater histamine concentrations 4 min after challenge compared with lavage from saline-challenged bronchi and 2) concentrations of eosinophils and macrophages that are greater than control lavage 8 min after exposure. Bronchial biopsies taken after CBE instillation also demonstrated a variable degree of subepithelial granulocyte infiltration that correlated with the global bronchoconstricting response to CBE assessed on a separate day. These studies suggest that inflammation can develop rapidly in normal human bronchi and may precede significant flow rate reductions by greater than 1 h.
Calcium-dependent regulation of airway epithelial chloride channels
Authors: Clancy J. P. , McCann J. D. , Li M. , Welsh M. J.
Published: December 2017

To determine how cell calcium ([Ca2+]c) regulates apical Cl- channels, we measured the rate of 125-Iodide (125I-) efflux to assay Cl- channel activity in intact cells and examined cell-free membrane patches from cultured canine tracheal epithelial cells. The Ca2+ elevating agonist bradykinin and the calcium ionophore A23187 increased 125I- efflux. This response did not require prostaglandin production. Under several conditions, changes in [Ca2+]c were temporally dissociated from changes in channel activation: a transient increase in [Ca2+]c caused a prolonged stimulation of 125I- efflux. Neither Cl- channel activation nor open-channel probability was affected by varying internal [Ca2+] in excised membrane patches. Adenosine 3',5'-cyclic monophosphate (cAMP)- and Ca2(+)-dependent channel activation may be independent: cAMP-stimulated 125I- efflux did not require an increase in [Ca2+]c, Ca2(+)-stimulated efflux did not require an increase in cAMP, and simultaneous addition of A23187 and isoproterenol produced additive effects on 125I- efflux. The data suggest that an increase in [Ca2+]c activates Cl- channels, however, the effect of Ca2+ appears to be indirect, not involving a ligand-type interaction with the channel.
Epithelial effects on tracheal smooth muscle tone: influence of muscarinic antagonists
Authors: Lev A. , Christensen G. C. , Zhang R. A. , Kelsen S. G.
Published: December 2017

The tracheobronchial epithelium produces factor(s) that modulate the constrictor and relaxant response of airway smooth muscle. The present study sought to determine whether the tracheobronchial epithelial inhibitory effect on trachealis smooth muscle tension is under muscarinic receptor control. Studies were performed on 195 strips from 13 rabbits. In strips in which the epithelium was intact, pirenzepine (an M1 receptor antagonist) produced a dose-related (10(-8) and 10(-7)M) rightward shift (P less than 0.01 for each) and gallamine (an M2 antagonist) produced a progressive (10(-8) and 10(-7)M) leftward shift of the acetylcholine concentration responses (P less than 0.01 for each). In strips in which the epithelium was removed mechanically, neither pirenzepine nor gallamine had any effect on the acetylcholine responses. In acetylcholine precontracted (5 x 10(-6) M) muscle strips with epithelium intact, addition of pirenzepine (10(-7)M) produced a significant (P less than 0.01) reduction in steady-state tension, whereas administration of gallamine tended to increase tension, (P = NS). Neither pirenzepine nor gallamine had any effect on steady-state tension in strips in which the epithelium was removed. These results indicate that the magnitude of the tracheobronchial epithelial inhibitory effect on smooth muscle tension is under muscarinic control. Specifically, M1 receptor blockade augments and M2 receptor blockade inhibits the magnitude of the tracheobronchial epithelial effect.
Angiotensin-converting enzyme kinetics in an endothelial cell column
Authors: Howell R. E. , Haselton F. R. , Mueller S. N.
Published: December 2017

The kinetics of saturable endothelial metabolic functions have been assessed in vivo by transient (indicator-dilution) measurements and in culture by steady-state measurements, but comparisons between the two are difficult. Therefore, we used indicator-dilution methods to assess the kinetics of angiotensin-converting enzyme (ACE) activity in cultured endothelium. Bovine fetal aortic endothelial cells were grown to confluence on microcarrier beads. Cell-covered beads were poured into polypropylene columns and perfused with serum-free culture medium. Six injections, containing [3H]benzol-Phe-Ala-Pro [( 3H]BPAP, an ACE substrate) and varying amounts of unlabeled BPAP, were applied to each column and effluent was collected in serial samples. The apparent kinetics of BPAP metabolism were determined by four models used previously to determine pulmonary endothelial ACE kinetics in vivo, the most useful model incorporating transit time heterogeneity. The Km averaged 5 microM, which is close to values determined previously in vivo and in vitro. The Amax (Vmax.reaction volume) and Amax/Km averaged 6 nmol/min and 1.5 ml/min, respectively, which are lower than estimates in vivo. In conclusion, we have developed a new method for investigating saturable metabolic activity in cultured endothelium, which after further exploration should also enable better comparisons of endothelial metabolic functions in vivo and in culture.
TGF-beta 1 modulation of urokinase and PAI-1 expression in human bronchial epithelial cells
Authors: Gerwin B. I. , Keski-Oja J. , Seddon M. , Lechner J. F. , Harris C. C.
Published: December 2017

Normal human bronchial epithelial (NHBE) cells respond to signals initiated by the binding of transforming growth factor-beta type 1 (TGF-beta 1) to its surface receptors by activating pathways that result in terminal squamous differentiation. By use of both normal and SV40 T-antigen-immortalized cells, it was found that treatment with TGF-beta 1 transiently increases mRNA levels for urokinase (uPA) and plasminogen activator inhibitor type 1 (PAI-1) approximately 5- and 50-fold, respectively, within 4 h. In NHBE cells, PAI-1 protein is increased by TGF-beta 1 in both extracellular matrix and medium. The net effect of TGF-beta 1 on plasminogen activator activity in the medium was a 50% reduction as measured by a caseinolytic assay. A T-antigen-immortalized bronchial epithelial cell line that does not undergo squamous differentiation in response to TGF-beta 1 but binds this growth factor did not respond to TGF-beta 1 by modulation of either uPA or PAI-1 expression. Comparison of human bronchial epithelial, pleural mesothelial, and lung fibroblastic cell strains indicated that the epithelial cells have a constitutively higher ratio of uPA to PAI-1 mRNA expression. These data suggest that modulation of pericellular proteolysis in bronchial epithelial cells in response to TGF-beta 1 represents a significant biological change in their pericellular environment. The induction of uPA and PAI-1 expression in human bronchial epithelial cells may be related to the ability of the cell to undergo squamous differentiation in response to TGF-beta 1. These observations identify specific changes in gene expression that may serve as markers for the differentiation process.(ABSTRACT TRUNCATED AT 250 WORDS)
Enzymatic activity is necessary for thrombin-mediated increase in endothelial permeability
Authors: Aschner J. L. , Lennon J. M. , Fenton J. W. , Aschner M. , Malik A. B.
Published: December 2017

alpha-Thrombin causes a dose-dependent increase in endothelial permeability as measured by the clearance rate of 125I-albumin across a monolayer of bovine pulmonary artery endothelial cells. We determined if an active catalytic site is necessary for the thrombin-mediated increase in endothelial permeability. alpha-Thrombin was reacted with 10-fold excess D-phenylalanyl-prolyl-arginine chloromethyl ketone (PPACK), an irreversible inhibitor that forms a covalent bond with thrombin's active site, producing an enzymatically inactive thrombin. PPACK completely inhibited the alpha-thrombin-mediated increase in 125I-albumin permeability. Similar results were obtained with gamma-thrombin, an enzymatically active alpha-thrombin form with an altered fibrinogen recognition domain. PPACK alone and the active site-inhibited PPACK-alpha-thrombin had no effect on permeability. Diisopropylphospho (DIP)-alpha-thrombin was effective only in very high concentrations (10(-6)M), and this effect was abolished by the addition of PPACK. These studies demonstrate that binding alone is insufficient for the thrombin-mediated increase in endothelial monolayer permeability. Thrombin's active catalytic site is a requirement for the increase in transendothelial albumin permeability.
Regulation of fetal lung maturation
Authors: Gross I.
Published: December 2017

The recent identification of the genes for the surfactant proteins has greatly facilitated the study of the regulation of fetal lung alveolar epithelial cell development at the molecular level. In general, expression of the genes for the surfactant proteins is enhanced by the same hormones that stimulate phospholipid synthesis. There are, however, some notable differences that indicate that the genes for the different components of surfactant are independently regulated. Species differences in the response of the surfactant proteins to hormones such as glucocorticoids and adenosine 3',5'-cyclic monophosphate have also been demonstrated. This review focuses on current knowledge of the hormonal regulation of the surfactant proteins against a background of previous studies of lung development.
Attenuation of acid aspiration edema with phalloidin
Authors: Goldman G. , Welbourn R. , Klausner J. M. , Alexander S. , Kobzik L. , Valeri C. R. , Shepro D. , Hechtman H. B.
Published: December 2017

Acid aspiration leads to pulmonary endothelial and epithelial cell (EC/EpC) injury characterized by increased permeability and polymorphonuclear (PMN) leukocyte diapedesis. Actin in the EC/EpC cytoskeleton has been shown to play a significant role in maintenance of the microvascular junction barrier. This study tests indirectly whether the development of permeability and diapedesis following acid aspiration is via disruption of the pulmonary cytoskeleton. Manipulation was achieved by the actin microfilament assembler phalloidin. Anesthetized rats (n = 88) underwent segmental lung installation of 0.1 ml saline or phalloidin (2 x 10(-6) M). Twenty minutes later 0.1 N HCl, saline, or phalloidin was introduced. After 3 h there was an increase in wet-to-dry weight (W/D) ratio of 6.6 and 5.1 in the HCl-injected and noninjected sides, protein concentration, 3,970 and 2,530 micrograms/ml, and accumulation of 93 PMN/ml (x 10(4] in bronchoalveolar lavage (BAL) of the HCl-injected lung. These values were higher than control animals. Local pretreatment with phalloidin attenuated acid-induced localized but not generalized permeability with reduction in W/D ratio, BAL protein concentration, and diapedesis (P less than 0.05). Acid injection into airways also led to elevated thromboxane B2 and leukotriene B4 levels in plasma and BAL (P less than 0.05) and generalized lung leukosequestration, events not affected by phalloidin. Taken together, these data suggest that acid aspiration lung injury is determined largely by loss of integrity of the pulmonary EC/EpC cytoskeleton with resultant loss of barrier function.
Development of type II pneumocytes in rat lung
Authors: Young S. L. , Fram E. K. , Spain C. L. , Larson E. W.
Published: December 2017

At a late stage of fetal development, the mammalian alveolar epithelium undergoes an abrupt differentiation as a part of the preparation of the lung for the postnatal demands of gas exchange. Some of the most striking changes occur in the type II pneumocytes as they lose their glycogen and start to produce the lamellated inclusion granules that contain pulmonary surfactant. Premature birth before adequate type II cell maturation results in the neonatal respiratory distress syndrome, which is frequently fatal. We have used serial ultrathin sectioning, electron microscopy, and three-dimensional reconstructions to study the ultrastructural features of maturation of rat type II cells from a single rat each at age gestational day 20 through adult stages. We found evidence over this time span for compartmentation of several secretory granule precursors within type II cells. Changes in the polarization of lamellar bodies were observed over the time period studied. We also found marked gestational changes in the number and morphology of type II cell cytoplasmic processes that perforate the basement membrane. Type II cell mitochondria changed in shape during postnatal development from single, spherical to complex, branched structures. Volume composition obtained from serial sections of a small number of type II cells agreed closely with published morphometric data, indicating that throughout the animal's lifespan, type II cells are a homogenous population.
Glucocorticoids induce neutral endopeptidase in transformed human tracheal epithelial cells
Authors: Borson D. B. , Gruenert D. C.
Published: December 2017

Neutral endopeptidase (NEP, also known as enkephalinase, CALLA, or EC 3.4.24.11) is a membrane-bound peptidase present in many different cell types. Previous studies have shown that it modulates the actions of a variety of biologically active peptides on several airway responses. More recent studies have demonstrated that reductions in neutral endopeptidase activity in animal airways is associated with increased responses to exogenously applied and endogenously released peptides. To study the regulation of NEP expression, we used human airway epithelial cells transformed in vitro with an origin-defective SV40 plasmid. Enzymatic activity, measured using [3H-Tyr,D-Ala2]leucine enkephalin, increased with cell density (1.4 ng/10(6) cells at 530 cells/cm2 and 21 ng/10(6) cells at confluence, 400 X 10(3) cells/cm2). In both confluent and nonconfluent cultures, the glucocorticoid budesonide increased neutral endopeptidase activity in time- and concentration-dependent fashions. Maximal increases of 10 ng/10(6) cells greater than control were observed after 6 days of incubation at 10(-7) M budesonide. Dexamethasone also increased NEP, suggesting that the effect is due to glucocorticoid receptor effects. Transcription, as assessed by Northern blot analysis of total cellular RNA, showed that NEP-specific RNAs also increased with increasing concentration of glucocorticoid. We conclude that neutral endopeptidase can be increased by cell growth or density and by glucocorticoids and that the effects of glucocorticoids are mediated by increased NEP gene expression.
A 90-kDa surface antigen of immature smooth muscle cells is ICAM-1
Authors: Printseva O. Yu. , Peclo M. M. , Tjurmin A. V. , Gown A. M.
Published: December 2017

A monoclonal antibody, designated 10F3, that reacts with an antigen of molecular mass 90,000 Da has been developed by immunization of BALB/c mice with smooth muscle cells in long-term culture. The cells were originally isolated from fetal human aorta. The 10F3 was identified as an antibody that reacts with the ICAM-1 molecule. ICAM-1 is a mesenchymal antigen that is lost during differentiation of cells other than endothelium but is reexpressed by the intimal cells of vessels involved in atherogenesis.

atherosclerosis; monoclonal antibodies
Alveolar uptake of lipid and protein components of surfactant
Authors: Fisher A. B. , Dodia C. , Chander A.
Published: December 2017

We investigated the clearance of radiolabeled natural surfactant from the alveolar space of the isolated perfused rat lung. 3H, 35S-natural surfactant was prepared from rat lungs that had been perfused with [methyl-3H]choline and [35S]methionine. The biosynthesized material contained greater than 95% of 3H in phosphatidylcholine (PC) and approximately 80% of 35S in surfactant protein A. Natural surfactant (1 mumol PC) was instilled into the trachea; lungs were analyzed 5 min later or after 2 h perfusion to determine surfactant uptake, defined as lung lavage-resistant 3H or 35S [% of instilled disintegrations per minute(dpm)]. Uptake at 5 min was 31.4 +/- 0.37% for 3H and 31.9 +/- 0.85% for 35S (mean +/- SE, n = 4). At 2 h, uptake was 46.6 +/- 0.96% for 3H and 45.8 +/- 1.1% for 35S (n = 7). In the presence of 0.1 mM 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP), uptake at 2 h for both 3H and 35S was stimulated to approximately 57% of instilled dpm (n = 4). Microsomes and plasma membranes isolated from lung homogenates had a ratio of 3H to 35S that was similar to the original surfactant, whereas 3H/35S in isolated lamellar bodies was increased 2.1-fold. Degradation of lipid was indicated by finding 13.4 +/- 0.65% of homogenate 3H in the aqueous fraction of lung extract after 2 h perfusion; only 2.3 +/- 0.47% of 35S dpm were soluble in trichloroacetic acid, suggesting significantly less protein breakdown. Lipid degradation was increased more than twofold by 8-BrcAMP, whereas protein degradation was not changed significantly.(ABSTRACT TRUNCATED AT 250 WORDS)
Impact for molecular biology in cardiology
Authors: Roberts Robert
Published: December 2017

The recent development and application of the techniques of recombinant DNA and molecular biology ignited an explosion in biomedical research, which has been embraced by medicine. However, cardiology as a subspecialty has been slower in adopting these techniques, in part because the heart is a nonproliferating organ and in part because it was not easily accessible until recently. The techniques of recombinant DNA were not possible until the 1970s. In that decade four major discoveries occurred that launched molecular biology into the 21st century. These seminal contributions were 1) the discovery and application of specific restriction endonucleases, 2) the discovery of reverse transcriptase, 3) the development of the cloning technique, and 4) the ability to rapidly sequence nucleic acids. The techniques of recombinant DNA offer several unique advantages over existing scientific disciplines, such as the abilities: 1) to perform in vivo structure-function analysis, 2) to genetically engineer drugs, 3) to perform diagnostic in situ hybridization, 4) to isolate genes responsible for hereditary disorders, and 5) to understand the genetic regulation of cardiac growth. These techniques are discussed in their application to cardiac disorders, including the development of new recombinant molecules for the treatment of coronary thrombosis and the potential to modulate the cardiac growth response to various forms of injury such as myocardial infarction and hypertension.

cardiac growth; genetic engineering; molecular genetics; structure function analysis
Related expression of arachidonate 12- and 15-lipoxygenases in animal and human lung tissue
Authors: Shannon V. R. , Crouch E. C. , Takahashi Y. , Ueda N. , Yamamoto S. , Holtzman M. J.
Published: December 2017

We examined the immunohistochemical distribution of the arachidonate 12- and 15-lipoxygenases in anima l and human lung tissue using a polyclonal anti-12/15-lipoxygenase antibody. Immunoblotting of whole cell extracts fro m bovine and human tracheal epithelial cells or from bovine leukocytes with the antibody (raised originally against pu rified porcine leukocyte 12-lipoxygenase) showed immunoperoxidase staining of a single protein band (Mr = 72,000), whi ch com igrated with purified bovine 12-lipoxygenase. The antibody also immunoprecipitated both 12- and 15-lipoxygenase activities from cytosolic fractions of bovine and human tracheal epithelial cells. Immunohistochemistry of formaldehyd e-fixed and paraffin-embedded bovine (and ovine and canine) trachea using the same polyclonal antibody and an indirect biotin-avidin-peroxidase detection system demonstrated specific staining of tracheal epithelium, polymorphonuclear and mononuclear leukocytes, and perineural cells. Less intense staining of submucosal glands and blood vessels was also ob served. Lung sections demonstrated that the level of lipoxygenase antigen decreased markedly by the level of the bronc hi and was absent in more distal airways. A similar pattern of immunostaining was found in human lung, except that air way smooth muscle was also weakly reactive, and polymorphonuclear (neutrophilic) leukocytes were unstained (in accorda nce with the low 12/15-lipoxygenase activity in this cell type). We conclude that animal and human epithelial 12/15-li poxygenases share enzymatic, antigenic, and regional distribution characteristics and may therefore possess a common f unction in the pulmonary airway.
Acetaldehyde-mediated cilia dysfunction in bovine bronchial epithelial cells
Authors: Sisson Joseph H. , Tuma Dean J. , Rennard Stephen I.
Published: December 2017

Pages L29–L36: Joseph H. Sisson, Dean J. Tuma, and Stephen I. Rennard. “Acetaldehyde-mediated cilia dysfunction in bovine bronchial epithelial cells”. In Figs. 1, 2, 4, and 5, the concentration of acetaldehyde in the figures and their legends should read mM (millimolar) instead of μM (micromolar). Page L34: right-hand column, the first sentence of the paragraph should read: The threshold concentrations of acetaldehyde-induced impairment in these studies was ap30 mM for ATPase inhibition and ciliostasis.
Muscarinic receptor subtypes in feline tracheal submucosal gland secretion
Authors: Ishihara H. , Shimura S. , Satoh M. , Masuda T. , Nonaka H. , Kase H. , Sasaki T. , Sasaki H. , Takishima T. , Tamura K.
Published: December 2017

To determine what muscarinic receptor subtype regulates [Ca2+]i mediating airway submucosal gland secretion, we examined the effects of atropine (Atr), pirenzepine (PZ), 11([2-(diethylamino)methyl-1-piperidinyl] acetyl)-5,11-dihydro-6H-pyrido (2,3-b)(1,4)-benzo-diazepin-6-one (AF-DX116) and 4-diphenylacetoxy-N-methyl-piperidine methiodide (4-DAMP) on methacholine (MCh)-evoked [Ca2+]i rise in acinar cells, and compared this with mucus glycoprotein (MGP) and electrolyte secretion evoked by MCh from submucosal glands isolated from feline trachea. [Ca2+]i was measured with the Ca(2+)-sensitive fluorescent dye, fura 2. We determined MGP secretion by measuring TCA-precipitable 3H-labeled glycoconjugates and electrolyte secretion by the change in the rate constant of 22Na-efflux from isolated glands. Half-maximal inhibitory concentrations (IC50) of PZ, AF-DX116, 4-DAMP, and Atr against MCh-evoked [Ca2+]i rise were 10(-7) M, 6 x 10(-6) M, 8 x 10(-9) M, and 6 x 10(-9) M, respectively. IC50 of PZ, AF-DX116, 4-DAMP, and Atr against MCh-evoked MGP secretion were 10(-6) M, 2 x 10(-5) M, 8 x 10(-9) M, and 6 x 10(-9) M, respectively. MCh (10(-5) M)-evoked 22Na efflux was significantly inhibited by 10(-7) M 4-DAMP and 10(-7) M Atr (P less than 0.01, each) but not by 10(-7) M PZ. Receptor binding assays with [3H]quinuclidinyl benzilate showed that the Ki values for PZ, AF-D x 116, 4-DAMP and Atr were 2.2 x 10(-8) M, 6.6 x 10(-7) M, 6.2 x 10(-10) M, and 2.9 x 10(-10) M, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Agonist-induced inositol phosphate responses in bovine airway submucosal glands
Authors: Hall I. P.
Published: December 2017

Agonist-induced inositol phosphate responses were investigated in bovine airway submucosal glands prelabeled with [3H]inositol. The agents used included muscarinic, adrenergic, and histaminergic agonists and NaF as a direct stimulant of phosphoinositidase C. Carbachol (1 microM-1 mM) produced concentration-related [3H]-inositol phosphate formation [maximal response 7.3-fold, half-maximal effective concentration (EC50) 47 microM]. This response was inhibited by atropine [affinity constant (Ka) 1.5 x 10(9) M-1], suggesting the involvement of a muscarinic receptor. Histamine (EC50 66 microM, 2.4-fold stimulation) and norepinephrine (EC50 28 microM, 2.7-fold stimulation) also produced concentration-dependent [3H]inositol phosphate responses. The response to histamine was inhibited by mepyramine (Ka 1.9 x 10(8) M-1), and the response to norepinephrine was inhibited by phentolamine (Ka 1.3 x 10(8) M-1) and prazosin (Ka 2.3 x 10(8) M-1), indicating the involvement of H1 and alpha 1-receptors, respectively, in these responses. NaF also produced concentration-dependent [3H]inositol phosphate formation compatible with the involvement of a G protein in this response. These results demonstrate that a range of secretagogues induce inositol phosphate responses in bovine airway submucosal glands. This response may underlie stimulus response coupling in this tissue.
Pulmonary arterial hypoxic contraction: signal transduction
Authors: Jin N. , Packer C. S. , Rhoades R. A.
Published: December 2017

The response of isolated rat pulmonary arteries to acute hypoxia has previously been reported to be biphasic, consisting of an initial rapid contraction of short duration, followed by partial relaxation (phase 1) and then a second slowly developed but sustained contraction (phase 2). The purpose of this study was to determine the following: 1) whether products from the endothelium might be required, 2) whether extra- and/or intracellular calcium or protein kinase C might be second messengers in mediating the pulmonary arterial hypoxic contraction, and 3) whether or not guanosine 3',5'-cyclic monophosphate (cGMP), endothelium-derived relaxing factor (EDRF), prostaglandin I2 (PGI2) or A2 adenosine receptor activation is involved in phase 1 relaxation. Neither Ca(2+)-free media nor verapamil (a Ca2+ channel blocker) altered the phase 1 contraction, but the phase 2 contraction was abolished by either of these treatments. Ryanodine (a sarcoplasmic reticulum Ca2+ depleter) had no effect on phase 1 contraction. H-7 (a PKC inhibitor) inhibited the phase 2 contraction, whereas it had no effect on phase 1 contraction. Removal of the endothelium abolished phase 1 contraction in either Ca(2+)-free media or normal Ca2+ media but did not alter phase 2 contraction or phase 1 relaxation. Neither methylene blue (guanylate cyclase inhibitor), N omega-nitro-L-arginine, (EDRF blocker), acetylsalicylic acid (cyclooxygenase inhibitor), xanthine amino congener (adenosine receptor blocker), nor glybenclamide blocked the phase 1 relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)
Processing of surfactant protein B proprotein by a cathepsin D-like protease
Authors: Weaver T. E. , Lin S. , Bogucki B. , Dey C.
Published: December 2017

Surfactant protein B (SP-B) is a hydrophobic peptide of relative molecular weight (M(r)) = 8,000 that is associated with pulmonary surfactant phospholipids. SP-B is synthesized by the alveolar type II epithelial cell as a proprotein of M(r) = 42,000 which requires at least two proteolytic cleavages to generate the 79 residue mature SP-B peptide. We have previously reported that cleavage of the NH2-terminal propeptide, to generate a processing intermediate of M(r) = 25,000, occurs in close temporal approximation to secretion. In the present study we demonstrate that SP-B proprotein, isolated from stably transfected Chinese hamster ovary cells, is processed to M(r) = 25,000 by a crude type II cell membrane fraction but not by intact type II cells or type II cell conditioned media. In vitro processing of the proprotein by the type II cell membrane preparation resulted in release of a single peptide of M(r) = 16,000–17,000, which was detected by antiserum directed against antigenic epitopes in propeptide of the precursor. SP-B processing activity was extracted by Na2CO3 lysis of the type II cell membrane preparation, had a pH optimum of 5.0–6.0, and was inhibited by 10(-7) M pepstatin A, suggesting that the NH2-terminal peptide of the precursor is cleaved by an aspartyl protease. Consistent with this hypothesis, processing of SP-B by a crude type II cell membrane preparation was blocked by antiserum directed against the aspartyl protease cathepsin D; further, purified cathepsin D efficiently processed the SP-B precursor to M(r) = 25,000. Collectively these results suggest that cleavage of the NH2-terminal propeptide of the SP-B precursor is mediated by cathepsin D or a cathepsin D-like protease localized within the secretory pathway of the type II epithelial cell.