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Mann GE, Yudilevich DL. Rapid transcapillary exchange and unidirectional neuronal uptake of noradrenaline in the perfused rabbit heart. J Physiol 1984; 348:589-600. [PMID: 6425496 PMCID: PMC1199419 DOI: 10.1113/jphysiol.1984.sp015127] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Capillary permeability and cellular uptake of noradrenaline by the isolated artificially perfused rabbit heart was measured using rapid (less than 30 s) single-circulation tracer-dilution techniques. In a single coronary circulation capillary extractions of L-[14C]noradrenaline and D-[3H]mannitol (extracellular reference) relative to an intravascular marker, 125I-labelled albumin, were similar and above 60%. The 'apparent' volume of distribution for tracer noradrenaline was 2.5-fold larger than that measured for D-mannitol (0.32 ml g-1) suggesting cellular uptake of the amine. Unidirectional noradrenaline uptake was estimated by directly comparing coronary sinus dilution profiles of L-[3H]noradrenaline and D-[14C]mannitol. Michaelis-Menten saturation kinetics based on a single-entry system were determined (Km = 2.8 +/- 1.5 microM, Vmax = 2.1 +/- 0.5 nmol min-1 g-1, n = 4) by perfusing hearts with varying concentrations of L-noradrenaline (1-10 microM). Various known inhibitors of noradrenaline uptake were investigated to determine whether uptake was mediated by neuronal (uptake1) and/or extraneuronal (uptake2) mechanisms. Desipramine (5 microM), imipramine (5 microM) and metaraminol (2 microM) resulted in a 66-94% inhibition of noradrenaline influx. In comparison, the steroids, 17 beta-oestradiol (1 microM) and corticosterone (10 microM), and the noradrenaline metabolite normetanephrine (5 microM) caused virtually no inhibitory effects. The beta-adrenergic antagonist propranolol (5 microM) was also relatively ineffective. These results together with the kinetic constants estimated suggest that the rapid noradrenaline uptake reflects transport into adrenergic neurones lying in the coronary interstitium. The high resolution of this paired-tracer dilution technique has permitted a 'non-invasive' study of neuronal uptake mechanisms and its application may be of clinical value.
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Mann GE, Yudilevich DL. Discrimination of parallel neutral amino acid transport systems in the basolateral membrane of cat salivary epithelium. J Physiol 1984; 347:111-27. [PMID: 6707951 PMCID: PMC1199437 DOI: 10.1113/jphysiol.1984.sp015056] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Transport of short-chain and long-chain neutral amino acids across the basolateral membrane of the epithelium in the perfused cat salivary gland has been studied using a rapid (less than 30 s) single circulation paired-tracer dilution technique. Amino acid uptake was measured by comparing the venous dilution profiles for a tritiated amino acid and D-[14C]mannitol (extracellular reference) following a bolus intra-arterial injection of a mixture containing both molecules. Unidirectional influx (v) was estimated from the maximal tracer uptake (Umax), the perfusate flow (F) and the perfusate amino acid concentration (Ca): v = [-F . ln (1-Umax)] . Ca. L-alanine influx was saturable and apparently mediated by a single entry system (Km = 0.83 +/- 0.11 mM and Vmax = 655 +/- 32 nmol/min . g). These kinetic constants were considerably lower than our previously reported values for L-phenylalanine: Km = 6.4 mM and Vmax = 1719 nmol/min . g. In cross-inhibition experiments performed over a wide range of concentrations (0.05-24 mM), influx of L-alanine and L-phenylalanine could be further discriminated, since both L-phenylalanine (Ki = 22 mM) and L-alanine (Ki = 19 mM) behaved as poor competitors. Removal of Na+ from the perfusate resulted in a selective inhibition of L-alanine and L-serine influx, whereas influx of the long-chain neutral amino acids L-leucine, L-phenylalanine and L-tryptophan remained unaffected. Although prolonged perfusion of glands with dinitrophenol (0.8 mM for 20-30 min) caused a variable but net inhibition of unidirectional uptake, it markedly enhanced the tracer efflux of L-leucine, L-phenylalanine, L-tyrosine and the basic amino acid L-lysine. It appears that at least two separate neutral amino acid transport systems are operative at the blood-tissue interface of the salivary epithelium: (i) a Na+-dependent alanine-serine-cysteine preferring type of carrier exhibiting a high affinity for amino acids with short, polar or linear side chains and (ii) a Na+-independent leucine preferring type of carrier selective for large neutral amino acids.
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Rennie MJ, Idström JP, Mann GE, Scherstén T, Bylund-Fellenius AC. A paired-tracer dilution method for characterizing membrane transport in the perfused rat hindlimb. Effects of insulin, feeding and fasting on the kinetics of sugar transport. Biochem J 1983; 214:737-43. [PMID: 6354176 PMCID: PMC1152310 DOI: 10.1042/bj2140737] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We have applied the paired-tracer dilution method to the study of transport processes in a mixed mammalian muscle preparation, the perfused rat hindlimb. The method is suitable for the characterization of the kinetic parameters of sugar and amino acid transport and its regulation by hormones, contractile activity, hypoxia, etc. Insulin stimulates sugar transport by increasing the Vmax. of the process 2-3 fold, but its affinity is unchanged. Starvation increases the affinity of sugar transport in perfused skeletal muscle.
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Yudilevich DL, Mann GE. Unidirectional uptake of substrates at the blood side of secretory epithelia: stomach, salivary gland, pancreas. FEDERATION PROCEEDINGS 1982; 41:3045-53. [PMID: 6754458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
This paper reviews studies of cellular uptake of substrates by the gastric mucosa, salivary gland, and pancreas by single-circulation, multiple tracer dilution techniques. The application of this methodology to secretory organs in vivo has permitted the characterization of transport phenomena at the blood-tissue interface of resting and secreting epithelia. To estimate uptake of a test molecule after an intraarterial injection, its venous concentration profile (30 samples in 1 in) was compared with that of 1) an intravascular marker or 2) a diffusible molecule that remains confined to the extracellular space. Among the molecules investigated were 86Rb, 57Co-labeled cyanocobalamin, 125I-labeled insulin, [3H]ouabain, [3H]dopamine, [3H]norepinephrine, and a wide range of labeled amino acids. High tracer uptake (80%) was measured that could be inhibited by specific unlabeled competitors. Unidirectional influx was saturable and Michaelis-Menten kinetic constants could be estimated. The ultimate objective was to identify various transport systems and/or receptors at the basolateral side of these epithelia. However, nerve terminals in the interstitium could be the major site for the uptake of catecholamines.
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Mann GE, Tradatti CE, Yudilevich DL. Unidirectional uptake of L-alanine and L-serine by system ASC in the basolateral membrane of cat salivary epithelium. Selective inhibition of rapid alanine metabolism by aminooxyacetate. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 692:157-60. [PMID: 6816278 DOI: 10.1016/0005-2736(82)90513-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Unidirectional influx of L-alanine and L-serine across the basolateral membrane of cat salivary epithelium was investigated in perfused submandibular glands using a rapid (less than 30 s) paired-tracer dilution technique. (Bustamante, J.C., Mann, G.E. and Yudilevich, D.L. (1981) J. Physiol. 313, 65-79). High uptakes were measured for both neutral amino acids, however, only the uptake of L-alanine was followed by an immediate tracer efflux into the circulation. Aminooxyacetate, an inhibitor of alanine aminotransferase, completely inhibited this efflux and glandular pyruvate production. These results demonstrate that in assessing unidirectional amino acid uptake, the influence of metabolism should be considered even during short intervals of measurement.
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Eaton BM, Mann GE, Yudilevich DL. Transport specificity for neutral and basic amino acids at maternal and fetal interfaces of the guinea-pig placenta. J Physiol 1982; 328:245-58. [PMID: 7131314 PMCID: PMC1225656 DOI: 10.1113/jphysiol.1982.sp014262] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
1. The unidirectional influx of amino acids into the guinea-pig syncytiotrophoblast was measured using a single circulation paired-tracer dilution technique which allows separate characterization of both fetal and maternal interfaces. An in situ preparation perfused through the fetal circulation was used to examine the fetal side, while an isolated preparation perfused through both the fetal and maternal circulations was used to study both interfaces simultaneously.2. On the fetal side the maximal uptake (U(max)) determined at tracer concentrations was high for the short-chain neutral amino acid alanine (76%) and the long-chain neutrals, leucine (75%), phenylalanine (90%) and tyrosine (82%) and for the basic amino acid lysine (65%). In contrast, U(max) was negligible for alpha-methylaminoisobutyric acid and taurine, a beta-amino acid.3. The uptake of alanine and phenylalanine on the fetal side was inhibited by both short-chain (alanine, serine, cysteine) and long-chain (phenylalanine, methionine, leucine) neutral amino acids. d-alanine had no effect on l-alanine uptake whereas d-phenylalanine significantly inhibited that of l-phenylalanine. Diaminobutyric acid, lysine and arginine were effective inhibitors of alanine uptake but had no effect on phenylalanine uptake.4. On the maternal side uptake of alanine, phenylalanine and lysine was measured. Over a wide range of concentrations self-inhibition of alanine influx was similar to the cross-inhibition observed with phenylalanine. In contrast, the influx of phenylalanine, which was strongly self-inhibited, was only partially cross-inhibited by alanine.5. Influx of alanine and phenylalanine was measured at various perfusate concentrations and was found to be saturable on both maternal and fetal sides. The data were fitted to a single hyperbola and, on the maternal side, the K(m) for alanine (10.3+/-2.7 mm, mean+/-s.e., n = 3) was three-fold higher than the value measured for phenylalanine (3.1+/-0.8 mm). On the fetal side the K(m) values for alanine (8.4+/-1.4 mm, n = 4) and phenylalanine (11.9+/-1.9 mm, n = 3) were similar.6. The uptake of alanine, phenylalanine and lysine appeared to be highly sodium-dependent accounting for 40-70% of the total influx. However, the inhibited fractions were found to be different on the two sides of the placenta.7. The results of uptake, cross-inhibition and Na(+)-dependency experiments suggest the presence of an alanine-serine-cysteine (ASC) type system and a leucine (L) type system with markedly overlapping specificities at both the fetal and maternal interfaces. Separate kinetic characterization of a two carrier system was not possible under the conditions of these experiments. However, kinetic parameters for the over-all transport of alanine and phenylalanine were measured.
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Mann GE. Alterations of myocardial capillary permeability by albumin in the isolated, perfused rabbit heart. J Physiol 1981; 319:311-23. [PMID: 6798198 PMCID: PMC1243840 DOI: 10.1113/jphysiol.1981.sp013910] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
1. Capillary permeability-surface area products for 22Na, 51Cr-EDTA (mol. wt. 357), [57Co]cyanocobalamin (mol. wt. 1353) and 125I-labelled insulin (mol. wt. approximately or equal to 6000) were measured using the single-passage, multiple-tracer dilution technique in isolated rabbit hearts perfused at constant flows between 0.2 and 4.7 ml. min-1 . g-1. 2. In hearts perfused with a Krebs-Ringer solution containing bovine albumin (10 g . l . -1), the permeability-surface area products for 51Cr-EDTA and [57Co]cyanocobalamin increased as the perfusion rate increased, but reached constant values at flows above 2 ml . min-1 . g-1. For 125I-labelled insulin a diffusion-limited value of 0.06 +/- 0.02 ml . min-1 . g-1 (mean +/- S.E., n = 10) was measured at significantly lower perfusion rates. As the value for 22Na increased continuously with increments in flow, only a flow-limited value could be estimated. 3. When hearts were initially perfused with albumin (10 g . l . -1) and then with an albumin-free Krebs-Ringer solution, a significant increase in the permeability-surface area for 22Na, 51Cr-EDTA and [57Co]cyanocobalamin was observed. 4. In hearts perfused with albumin capillary permeability coefficients calculated for 22Na, 51Cr-EDTA. [57Co]cyanocobalamin and 125I-labelled insulin were respectively: 10.5, 3.5, 2.1 and 0.21 x 10(-5) cm.sec-1. 5. These findings confirm that bovine albumin reduces the permeability of myocardial capillaries to hydrophilic solutes of varying molecular sizes and this effect may be the result of an interaction of albumin with the pathways for transcapillary exchange.
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Bustamante JC, Mann GE, Yudilevich DL. Specificity of neutral amino acid uptake at the basolateral side of the epithelium in the cat salivary gland in situ. J Physiol 1981; 313:65-79. [PMID: 7277237 PMCID: PMC1274437 DOI: 10.1113/jphysiol.1981.sp013651] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
1. Amino acid uptake was measured in resting cat submandibular glands with either a natural blood supply or perfused at constant flow with a Krebs-albumin solution. Following a bolus arterial injection of a 3H-labelled amino acid and D-[14C]mannitol (extracellular reference tracer), the venous effluent was immediately sampled sequentially. The maximal uptake, Umax, from the blood or perfusate was determined from the paired-tracer dilution curves using the expression: uptake % = (1 -- (3H/14C) X 100). 2. In glands with a natural blood supply, Umax values up to 46% were measured for short-chain (serine and alanine) and long-chain (valine, methionine, leucine, isoleucine, 1-amino-cyclopentane cyclopentane carboxylic acid, phenylalanine, tryptophan, tyrosine, histidine and glutamine) neutral amino acids. In contrast, Umax was negligible for amino acids of the imino-glycine group (proline and glycine) and the nonmetabolized amino acids, 2-aminoisobutyric acid (AIB) and methylaminoisobutyric acid (MeAIB). 3. In glands with a natural blood supply addition of an unlabelled amino acid to the tracer injectate reduced Umax for the test acid by up to 80%. The pattern of these interactions suggested the presence of two transport systems for neutral amino acids, one preferring short-chain and the other long-chain amino acids. 4. In glands perfused at constant flow rates with an amino acid-free Krebs-albumin solution high Umax values were measured: L-serine (66%), L-alanine (54%), L-leucine (43%), L-phenylalanine (42%) and L-tyrosine (51%). Only a low uptake was observed for L-proline (8%) and glycine (14%). There was no uptake of methylaminoisobutyric acid which confirms the result obtained in glands with an intact circulation. 5. Saturation of L-phenylalanine influx was observed in perfused glands as the perfusate concentration of unlabelled L-phenylalanine was increased from 0.5 to 20 mmol . 1-1. A Michaelis--Menten analysis based on a single entry system indicated an apparent Km of 6.4 +/- 0.8 mmol . 1-1 and a Vmax of 1719 +/- 94 nmol . min-1g.-1 6. Since the fenestrated capillaries in the salivary gland are readily permeable to the test amino acid and D-mannitol, it is most probable that the amino acid carriers are located in the basolateral side of the epithelium. 7. The use of a paired-tracer dilution technique to measure uptake in a single circulatory passage has enabled a detailed characterization of neutral amino acid transport in the salivary gland and has overcome the limitation of previous studies based on solute transfer from blood to saliva.
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Jones CJ, Mann GE, Smaje LH. The role of cyclic nucleotides and related compounds in nerve-mediated vasodilatation in the cat submandibular gland. Br J Pharmacol 1980; 68:485-97. [PMID: 6301594 PMCID: PMC2044196 DOI: 10.1111/j.1476-5381.1980.tb14563.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
1 Intra-arterial administration of a number of purine compounds to the cat submandibular salivary gland led to an increased blood flow. The threshold concentration of the most potent vasodilators, adenosine 5'-triphosphate (ATP) and adenosine 5'-diphosphate (ADP) was about 2 mumol/l. Adenosine and guanosine 5'-triphosphate (GTP) required about 25 mumol/l, adenosine 3',5'-cyclic monophosphate (cyclic AMP) 40 mumol/l, guanosine 5'-diphosphate (GDP) 125 mumol/l and dibutyryl guanosine 3',5' cyclic monophosphate (db cyclic GMP) 400 mumol/l. Dibutyryl cyclic AMP and cyclic GMP were ineffective. 2 The cyclic nucleotide phosphodiesterase inhibitors, theophylline, papaverine, quinine and 3-isobutyl-1-methylxanthine (IBMX), all acted as vasodilators. 3 When intra-arterial infusion of theophylline or IBMX was combined with sympathetic nerve stimulation, the vasodilatation observed after the stimulus ceased was significantly potentiated. 4 Theophylline and IBMX also potentiated the vasodilatation accompanying parasympathetic nerve stimulation and this response persisted after atropine. 5 These results are discussed in relation to the possible mediators of sympathetic and parasympathetic vasodilatation in the gland.
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Mann GE, Smaje LH, Yudilevich DL. Permeability of the fenestrated capillaries in the cat submandibular gland to lipid-insoluble molecules. J Physiol 1979; 297:335-54. [PMID: 395293 PMCID: PMC1458723 DOI: 10.1113/jphysiol.1979.sp013043] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
1. Permeability-surface area products for the fenestrated capillaries in the perfused cat submandibular gland have been measured for graded lipid-insoluble molecules using the single-passage, multiple-tracer dilution technique. 2. The permeability-surface area for [57Co]cyanocobalamin (mol. wt. 1353) increased as the perfusion flow was increased, but reached a constant value of 4.11 +/- 0.25 ml.min-1.g-1 (mean +/- S.E., n = 9) at flows above 8 ml. min-1.g-1. For [125I]insulin (approximate mol. wt. 6000) it was 1.80 +/- 0.13 ml.min-1.g-1 (mean +/- S.E., n = 9) and apparently diffusion-limited at all the high flow rates studied. A similar permeability-surface area product was measured for [14C]inulin (mol. wt. 5500): 1.76 +/- 0.10 (mean +/- S.E., n = 4). 3. Permeability-surface area values for cyanocobalamin and insulin in the salivary gland are respectively about 20 and 200 times larger than the estimates reported for the continuous capillaries of cardiac and skeletal muscle. 4. The permeability-surface area (PS) ratio [57Co]cyanocobalamin/[125I]insulin (2.33 +/- 0.15, mean +/- S.E., n = 9) was significantly greater than the apparent ratio of their free diffusion coefficients (1.76), suggesting restricted diffusion of insulin relative to cyanocobalamin across the capillary endothelium. 5. Permeability-surface area products for the smaller molecular weight tracers (22Na, 86Rb and 51Cr-EDTA (mol. wt. 357)) increased continuously with perfusion rate, indicating flow-limited solute exchange. The PS ratio of Rb/EDTA was close to unity whereas the corresponding free diffusion ratio is 3.85. 6. The high permeability-surface area values measured were thought to be associated with the fenestrae which appeared to act as high concentrations of 'small pores' rather than as 'large pores'.
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Mann GE, Smaje LH, Yudilevich DL. Transcapillary exchange in the cat salivary gland during secretion, bradykinin infusion and after chronic duct ligation. J Physiol 1979; 297:355-67. [PMID: 119844 PMCID: PMC1458724 DOI: 10.1113/jphysiol.1979.sp013044] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
1. Capillary permeability-surface area products for 86Rb, [51Cr]EDTA (mol. wt. 357), [57Co]cyanocobalamin (mol. wt. 1353) and [125I]insulin (approximate mol. wt. 6000) have been measured using the single-circulation, multiple-tracer dilution technique in the in situ perfused submandibular salivary gland during parasympathetic nerve stimulation, close-arterial bradykinin infusion and following chronic duct ligation. 2. In glands with a natural blood supply, permeability-surface area for 86Rb and [51Cr]EDTA increased during parasympathetic stimulation, but this was shown to be related to the concomitant increase in blood flow rather than to a change in capillary permeability or in surface area. 3. In glands perfused at constant flow, parasympathetic stimulation led to a decrease in permeability-surface area for EDTA (-19.1 +/- 5.2%, mean +/- S.E., n = 5, P less than 0.05) cyanocobalamin (-12.3 +/- 6.0, n = 12, P less than 0.05), and insulin (-15.3 +/- 4.8, n = 11, P less than 0.02). It is suggested that this may be the result of a redistribution of flow from the acinar microcirculation to a less permeable ductal vasculature. 4. Bradykinin infusion had no significant effect on permeability-surface area for EDTA and cyanocobalamin in perfused glands. 5. In perfused glands, ligation of the submandibular duct for 3--12 days reduced permeability-surface area (ml.min-1.g-1) for [51Cr]EDTA from 5.26 +/- 0.60 (mean +/- S.E., n = 9) to 4.20 +/- 0.12 (n = 4, P less than 0.30), [57Co]cyanocobalamin from 3.22 +/- 0.12 (n = 48) to 2.02 +/- 0.08 (n = 15, P less than 0.001) and [125I]insulin from 1.52 +/- 0.07 (n = 39) to 0.72 +/- 0.23 (n = 11, P less than 0.001).
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187
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Bustamante JC, Mann GE, Yudilevich DL. Characterization of neutral amino acid carriers at the basal side of salivary epithelium by paired-tracer single circulation [proceedings]. J Physiol 1979; 291:26P-28P. [PMID: 383949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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188
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Mann GE. Capillary permeability-surface area products in the isolated, perfused rabbit heart [proceedings]. J Physiol 1979; 291:7P-8P. [PMID: 480259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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189
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Mann GE, Smaje LH, Yudilevich DL. Restricted distribution of molecules in the cat salivary gland interstitium [proceedings]. J Physiol 1979; 289:22P. [PMID: 458651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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190
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Yudilevich DL, Sepúlveda FV, Bustamante JC, Mann GE. A comparison of amino acid transport and ouabain binding in brain endothelium and salivary epithelium studied in vivo by rapid paired-tracer dilution. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 1979:15-27. [PMID: 290752 DOI: 10.1007/978-3-7091-2243-3_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Amino acid tmransport at the luminal side of brain capillary endothelium and the basal side of salivary epithelium were compared using a nondestructive, first-circulation, paired-tracer dilution method. In the brain, the reference molecule was an intravascular marker (Crone's method) whereas inthe salivary gland the reference was an extracellular marker of similar size to the test molecule. The unidirectional flux was related to a maximal uptake, U: U = 1 --test concentration/reference concentration Uptake and cross-inhibition experiments in brain suggest the presence of only a long-chain neutral L-amino acid transport system (leucine, phenyl-alanine, tryptophan, tyrosine, valine, methionine). In contrast, results in the salivary gland suggest 4 transport systems: 1. large neutral, 2. small neutral (alanine, serine), 3. basic (lysine) and 4. acidic (aspartic, glutamic). The same method was applied to localize binding sites. Ouabain bound very significantly to the salivary epithelium but not at all to the brain endothelium. The method described is of interest since it can be extended to any organ and possibly to man.
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191
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Bustamante JC, Mann GE, Yudilevich DL. An in vivo study of amino acid carriers in the salivary epithelium [proceedings]. J Physiol 1978; 285:31P. [PMID: 745085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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192
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Mann GE, Smaje LH, Yudilevich DL. Epithelial uptake of vitamin B12 in the cat salivary gland [proceedings]. J Physiol 1978; 285:32P. [PMID: 745087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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193
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Jones CJ, Mann GE. A possible role for adenosine 3':5'-cyclic monophosphate in nerve-mediated vasodilatation. Biochem Soc Trans 1977; 5:428-30. [PMID: 198258 DOI: 10.1042/bst0050428] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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194
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Stack BC, Funt LA, Mann GE. The diagnosis of TMJ disorders using laminographic radiography. VIRGINIA DENTAL JOURNAL 1977; 54:10-6. [PMID: 269571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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195
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Stack BC, Funt LA, Mann GE. The diagnosis of TMJ disorders using laminographic radiography. JOURNAL OF THE MARYLAND STATE DENTAL ASSOCIATION 1977; 20:18-23. [PMID: 267709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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196
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Mann GE, Smaje LH, Yudilevich DL. Proceedings: Vascular permeability in the perfused cat salivary gland using single passage multiple tracer dilution. J Physiol 1976; 258:58P-59P. [PMID: 957178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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197
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Codifer LP, Mann GE, Dollear FG. Aflatoxin inactivation: treatment of peanut meal with formaldehyde and calcium hydroxide. J AM OIL CHEM SOC 1976; 53:204-6. [PMID: 1262679 DOI: 10.1007/bf02633305] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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198
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Womack WR, Mann GE, Duranski V. Control in the orthodontic office. THE ARIZONA DENTAL JOURNAL 1974; 20:12-6. [PMID: 4530706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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199
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Mann GE, Codifer LP, Gardner HK, Koltun SP, Dollear FG. Chemical inactivation of aflatoxins in peanut and cottonseed meals. J AM OIL CHEM SOC 1970; 47:173-6. [PMID: 5467563 DOI: 10.1007/bf02638746] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Dollear FG, Mann GE, Codifer LP, Gardner HK, Koltun SP, Vix HL. Elimination of aflatoxins from peanut meal. J AM OIL CHEM SOC 1968; 45:862-5. [PMID: 5749435 DOI: 10.1007/bf02540171] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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