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  • 11
    Electronic Resource
    Electronic Resource
    Sodium-dependence of the saturability of carrier-mediated noradrenaline efflux from noradrenergic neurones in the rat vas deferens (1986)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 332 (1986), S. 131-134 
    Details
    ISSN: 1432-1912
    Keywords: Neuronal efflux ; Noradrenaline carrier ; Veratridine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The carrier-mediated transport of 3H-noradrenaline out of noradrenergic neurones was studied in vasa deferentia obtained from rats after pretreatment with reserpine and pargyline (to inhibit vesicular storage and monoamine oxidase, respectively). The tissue was first preincubated with various concentrations of 3H-noradrenaline (0.3–100 μmol/l; 30 min) and then washed out for 110 min with amine-free medium. During the last 10 min of washout, carrier-mediated neuronal efflux of 3H-noradrenaline was elicited by exposure to either Na+-free medium or 100 μmol/l veratridine; it was measured at 1-min intervals. 2. While the peak rates of carrier-mediated 3H-noradrenaline efflux elicited by Na+-free medium were linearly related to the 3H-noradrenaline content of the tissue (which cannot be raised beyond a certain maximal value, since uptake is saturable), those evoked in response to veratridine approached saturation as the 3H-noradrenaline level in the tissue was raised. Hence, saturation of 3H-noradrenaline outward transport was demonstrated at high (exposure to veratridine), but not at low (exposure to Na+-free medium) intraneuronal Na+ concentrations. 3. The results indicate that the K m for the mediated outward transport of noradrenaline across the plasma membrane of noradrenergic neurones is inversely related to the internal Na+ concentration, just as the K m for the mediated inward transport of noradrenaline (i.e., the neuronal noradrenaline uptake) is inversely related to the external Na+ concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00511402
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  • 12
    Electronic Resource
    Electronic Resource
    Total body, systemic and pulmonary clearance and fractional extraction of unlabelled and differently 3H-labelled noradrenaline in the anaesthetized rabbit (1988)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 338 (1988), S. 361-367 
    Details
    ISSN: 1432-1912
    Keywords: Noradrenaline clearance ; Fractional noradrenaline extraction ; Differently 3H-labelled noradrenaline ; Plasma DOPEG ; Anaesthetized rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Rabbits were anaesthetized with urethane/chloralose and infused intravenously with trace amounts of 3H-2,5,6-, 3H-7,8- or 3H-7-(-)noradrenaline either without or with unlabelled (\t-)noradrenaline being simultaneously infused (0.2 gg kg\t-1 min\t-1). To obtain clearance values and extraction ratios for the pulmonary, systemic and total circulation, steady-state concentrations of infused noradrenaline were determined in mixed central venous (C v) and arterial (C v) plasma. Heart rate and blood pressure were recorded via the carotid artery, and the dye dilution method was used to determine the cardiac output of plasma. 2. The simultaneous infusion of unlabelled noradrenaline, which increased plasma levels of noradrenaline by a factor of 5, had no significant effect on either heart rate, blood pressure or cardiac output (when determined at steady state of the noradrenaline infusion). 3. The simultaneous infusion of unlabelled noradrenaline did not affect the clearance values of any of the three type of 3H-noradrenaline. Moreover, the clearances of the various types of 3H-noradrenaline were virtually identical and agreed with that of unlabelled noradrenaline. However, the clearance of labelled and unlabelled noradrenaline from arterial plasma was 1.15 times higher than that from central venous plasma. This factor corresponded to the ratio of C v/C a and pointed towards net removal of noradrenaline from the pulmonary circulation. 4. The fractional pulmonary extractions [1 - (C a/C a)] of the three types of 3H-noradrenaline did not differ from each other and were not affected by the simultaneous infusion of unlabelled noradrenaline. Moreover, the fractional pulmonary extraction of endogenous noradrenaline resembled that of infused 3H- and unlabelled noradrenaline, suggesting that there was little, if any, overflow of endogenous noradrenaline into plasma during passage through the pulmonary circulation. 5. From the clearance of noradrenaline from mixed central venous plasma, its fractional pulmonary extraction and the cardiac output of plasma estimates of the following steady-state kinetic parameters for infused noradrenaline were obtained: pulmonary, systemic as well as total body clearance (13.4, 67.9, 72.6 ml kg\t-1 min\t-1) and fractional extraction (0.128, 0.650, 0.695). The rates at which infused noradrenaline was eliminated from the pulmonary and systemic circulation amounted to 18.4 and 81.6% of the total body elimination rate, respectively. 6. The infusion of unlabelled noradrenaline increased plasma levels of 3,4-dihydroxyphenylglycol (DOPEG) by a factor of 1.2. DOPEG concentrations in arterial plasma were 4.9% higher than those in mixed central venous plasma. Hence, there was some net formation of DOPEG in the pulmonary circulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00172110
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  • 13
    Electronic Resource
    Electronic Resource
    The role of extraneuronal amine transport systems for the removal of extracellular catecholamines in the rabbit (1996)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 354 (1996), S. 275-286 
    Details
    ISSN: 1432-1912
    Keywords: Key words Plasma clearance of catecholamines ; MAO-inhibition ; COMT-inhibition ; Disprocynium24 ; Uptake2 ; Organic cation transporters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract As selective inhibitors of the extraneuronal monoamine uptake system (uptake2) suitable for in-vivo studies were not available, the question of whether uptake2 plays a definite role in vivo is largely unresolved. We attempted to resolve the question by using 1,1′-diisopropyl-2,4′-cyanine iodide (disprocynium24), a novel agent that blocks uptake2 in vitro with high potency. Anaesthetized rabbits were infused with 3H-labelled noradrenaline, adrenaline and dopamine, and catecholamine plasma clearances as well as rates of spillover of endogenous catecholamines into plasma were measured before and during treatment with either disprocynium24 or vehicle. Four groups of animals were studied: group I, no further treatment; group II, monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) inhibited; group III, neuronal uptake (uptake1) inhibited; group IV, uptake1 as well as MAO and COMT inhibited. Disprocynium24 (270 nmol kg–1 i.v. followed by an i.v. infusion of 80 nmol kg–1 min–1) did not alter heart rate and mean arterial blood pressure, but increased cardiac output by 22% and decreased the total peripheral vascular resistance by 16% with no difference between groups. When compared with vehicle controls, catecholamine clearances (normalized for the cardiac output of plasma) were decreased and spillover rates increased in response to disprocynium24. Although there were statistically significant between-group differences in baseline clearances (which decreased in the order: group I 〉 group II 〉 group III 〉 group IV), the drug-induced clearance reductions relative to vehicle controls were similar in groups I to IV and amounted to 29–38% for noradrenaline, 22–31% for adrenaline and 16–22% for dopamine. Hence, there was still a significant % reduction in catecholamine clearances even after the combined inhibition of MAO and COMT, and there was no increase in the % reduction of clearances after inhibition of uptake1. Noradrenaline spillover increased in response to disprocynium24 in all four groups by 1.6- to 1.9-fold, whereas a 1.5- to 2.0-fold increase in adrenaline and dopamine spillover was observed in groups II and IV only. The results indicate that disprocynium24 interferes with the removal of circulating catecholamines not only by inhibiting uptake2, but also by inhibiting related organic cation transporters. As disprocynium24 increased the spillover of endogenous catecholamines into plasma even after inhibition of MAO and COMT, organic cation transporters may also be involved in the removal of endogenous catecholamines before they enter the circulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00171058
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  • 14
    Electronic Resource
    Electronic Resource
    Time-dependent changes in neuronal net uptake of noradrenaline after pretreatment with pargyline and/or reserpine (1971)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 271 (1971), S. 1-28 
    Details
    ISSN: 1432-1912
    Keywords: Noradrenaline Uptake ; Block of Monoamine Oxidase ; Reserpine ; Axoplasmic Noradrenaline ; Perfused Rabbit Hearts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Isolated rabbit hearts were perfused with 20 to 200 ng/ml of (−)-noradrenaline and arterio-venous differences were determined at various times to measure the rate of net removal of the amine from the perfusion fluid. Animals were untreated or pretreated with reserpine and/or pargyline to block vesicular retention and/or intraneuronal monoamine oxidase (MAO). The arterio-venous difference (in percent of the arterial concentration) remained rather constant during prolonged perfusions of untreated hearts with (−)-noradrenaline, the magnitude of the difference being inversely related to the arterial concentration. After block of MAO the rate of net removal declined exponentially with time; the rate of decline increased with increasing arterial concentration of the amine and also after the additional pretreatment with reserpine. The time-dependent decline in the rate of net removal was shown to be due to an increased efflux of the amine from the nerve endings. The net removal of noradrenaline-H3 at the 5th min of perfusion of pargyline-pretreated hearts was mainly due to neuronal net uptake, since a) O-methylation accounted for only 5% of the removal, and b) cocaine (10–30 (μg/ml) virtually abolished net removal. Initial rates of removal were not affected by the various pretreatments. In untreated hearts retention of exogenous (−)-noradrenaline increased linearly with the duration of the perfusion but the increase was exponential after block of MAO. Apparently, the storage capacity becomes exhausted during prolonged perfusions of pargyline-pretreated hearts. The ratio “noradrenaline retained by the heart/noradrenaline removed by the heart” was quite small in untreated (0.16), very small in reserpine-pretreated (0.03) and nearly unity in pargyline-pretreated hearts. It is concluded that any impairment of the intraneuronal mechanisms of inactivation (vesicular storage and MAO) leads to an increase in the axoplasmic concentration of free noradrenaline which causes an increased efflux of the amine, while the influx remains unchanged. The axoplasmic concentration of free noradrenaline seems to rise more after block of MAO than after pretreatment with reserpine and is most pronounced after both. Changes in the sensitivity of the pacemaker to (−)-noradrenaline were found to be correlated with changes in the rate of removal of the amine from the perfusion fluid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01002171
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  • 15
    Electronic Resource
    Electronic Resource
    The influence of block of catechol-O-methyl transferase on the sensitivity of isolated organs to catecholamines (1971)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 271 (1971), S. 59-92 
    Details
    ISSN: 1432-1912
    Keywords: Supersensitivity to Catecholamines ; Block of COMT-U-0521 ; V-0521 ; Isolated Nictitating Membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The sensitivity of various isolated organs to catecholamines was tested before and after block of catechol-O-methyl transferase (COMT) by U-0521 (3′,4′-dihydroxy-2-methyl propiophenone; 18 μg/ml for 20 min). Isolated Nictitating Membrane of the Cat. The sensitivity to catecholamines was increased by inhibition of COMT whenever the experimental conditions resulted in a high potency of the amine, i.e., when the ED50 of the amine (in the absence of U-0521) was below about 10−6 M. Thus, block of COMT potentiated the effects of (−)-noradrenaline and (−)-adrenaline after denervation (or in the presence of cocaine) but not on muscles with an intact adrenergic innervation; it also increased the sensitivity to theβ-effects but not to theα-effects of isoprenaline. No potentiation was observed for dopamine which has a low potency even after denervation. The relation between potency of the catecholamine and the degree of the sensitizing effect of U-0521 was not due to saturation of COMT or of access to the enzyme. Measurements in denervated muscles of the production of O-methylated metabolites from (±)-noradrenaline-H3 (added to the bath for 20 min in concentrations of about 10−7 to 10−4 M), and of the extraneuronal accumulation of noradrenaline-H3 did not reveal any saturation of either the enzyme or the extraneuronal accumulation of the amine. When block of COMT resulted in supersensitivity to a catecholamine, the time required to reach steady-state responses was usually increased. This is consistent with the view that block of the enzyme impaired a site of loss. Block of COMT failed to produce any substantial potentiation of the effects of the indirectly acting amines, tyramine and mephentermine. O-methylation of the released transmitter seems to occur after the amine has reached the receptors of the effector cells. Isolated Strips of Cat and Bat Spleen. Results were quantitatively similar, since block of COMT potentiated the effects of (−)-noradrenaline and (−)-adrenaline in the presence but not (or only very little) in the absence of cocaine. However, the degree of supersensitivity after block of COMT (in the presence of cocaine) was smaller than in the nictitating membrane. In the cat spleen, cocaine causes a small but significant degree of supersensitivity to isoprenaline but not to methoxamine. Isolated Sat Aorta, Block of COMT did not increase the effect of cocaine. It is suggested that differences in the morphology of the adrenergic innervation contribute to the observed organ differences.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01002173
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  • 16
    Electronic Resource
    Electronic Resource
    Choline+: A substrate of the neuronal noradrenaline carrier in the rat vas deferens (1986)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 334 (1986), S. 223-227 
    Details
    ISSN: 1432-1912
    Keywords: Neuronal noradrenaline carrier ; Choline+ ; Accelerative exchange diffusion ; Substitution for Na+ ; Rat vas deferens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The effects of choline+ (10–40 mmol/l) on 3H-noradrenaline uptake by, and 3H-noradrenaline efflux from, noradrenergic neurones were studied in vasa deferentia of reserpine-pretreated rats at an external Na+ concentration of 100 mmol/l. Monoamine oxidase and catechol-O-methyltransferase were inhibited. 2. Choline+ (20 and 40 mmol/l) competitively inhibited the neuronal uptake of 3H-noradrenaline. From the choline+-induced changes in the apparent Km for 3H-noradrenaline transport, a Ki of 35 mmol/l was obtained. 3. Choline+ (10, 20 and 40 mmol/l) accelerated the neuronal efflux of 3H-noradrenaline in a concentration-dependent manner. This acceleration of efflux was greatly reduced in the presence of 1 μmol/l desipramine, indicating that choline+ is capable of eliciting “accelerative exchange diffusion”. 4. Choline+ (40 mmol/l) and (−)noradrenaline (4.5 μmol/l) (i.e., concentrations about equivalent to the Ki and Km for choline+ and (−)noradrenaline, respectively) produced virtually identical increases in the neuronal efflux of 3H-noradrenaline. 5. Choline+ (3–300 mmol/l) inhibited the specific binding of 3H-desipramine to plasma membranes derived from cultured rat phaeochromocytoma (PC-12) cells. The Ki for this interaction was 48 mmol/l. 6. This results suggest that choline+ acts as alternative substrate of the neuronal noradrenaline transport system and should, therefore, not be used in transport studies with noradrenaline as substitute for Na+ in Na+-deficient media.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00508775
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  • 17
    Electronic Resource
    Electronic Resource
    Failure of K+ to affect the potency of inhibitors of the neuronal noradrenaline carrier in the rat vas deferens (1987)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 335 (1987), S. 250-254 
    Details
    ISSN: 1432-1912
    Keywords: High K+ ; Neuronal uptake ; Inhibition of neuronal uptake ; Potencies of uptake inhibitors ; Rat vas deferens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. To examine whether K+ affects the potency of inhibitors of neuronal uptake, experiments were carried out in the rat vas deferens after pretreatment of the animals with reserpine and after inhibition of monoamine oxidase and catechol-O-methyltransferase. Initial rates of the neuronal uptake of 3H-noradrenaline and IC50 values for uptake inhibition by desipramine, cocaine and (−)metaraminol were determined in the presence of various concentrations of external K+ (5–45 mmol/l), both at 100 mmol/l Na+ and 50 mmol/l Na+. 2. When measured at the 3H-noradrenaline concentration used to determine IC50 values (0.024 μmol/l), neuronal uptake was progressively impaired by increasing K+ concentrations at 50, but not at 100 mmol/l Na+. 3. Neither at 100 mmol/l Na+ nor at 50 mmol/l Na+ was there any consistent, concentration-dependent effect of K+ on the IC50 values of desipramine, cocaine and (−)metaraminol. 4. The analysis of the saturation kinetics of 3H-noradrenaline uptake (determined in the presence of 50 mmol/l Na+ at 5 mmol/l K+ or 45 mmol/l K+) showed that high K+ concentrations inhibit neuronal uptake by decreasing V max without any change in K max. 5. The results indicate that K+ does not competitively interact with Na+ at sites on the noradrenaline carrier which mediate the tansport-stimulating properties of Na+ Hence, the inhibition of neuronal uptake produced by high K+ concentrations is probably due to membrane depolarization which simply reduces V max.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00172792
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  • 18
    Electronic Resource
    Electronic Resource
    The heterogeneity of the neuronal distribution of exogenous noradrenaline in the rat vas deferens (1990)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 342 (1990), S. 160-170 
    Details
    ISSN: 1432-1912
    Keywords: Rat vas deferens ; Heterogeneous labelling ; 3H-noradrenaline ; Desipramine ; Inhibition of vesicular uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary After loading of the incubated rat vas deferens with 0.2 μmol/l 3H-noradrenaline (followed by 100 min of wash-out with amine-free solution), the efflux of endogenous and exogenous compounds was determined by HPLC with electrochemical detection and by column chromatography with scintillation counting. Two different types of heterogeneity of labelling were found. The first one is due to the preferential labelling of varicosities close to the surface of the tissue, the second one to the preferential labelling of vesicles close to the surface of loaded varicosities. As diffusion distances within the tissue and within varicosities are then longer for endogenous than for exogenous amine and metabolites, the composition of spontaneous efflux of exogenous compounds differed from that for endogenous compounds. Because of preferential neuronal and vesicular re-uptake of endogenous noradrenaline, the percentage contribution by noradrenaline to overall efflux was: endogenous 〈 exogenous. While 3H-DOPEG was the predominant exogenous metabolite, DOPEG and MOPEG equally contributed to the “endogenous” efflux. Desipramine abolished the consequences of the first heterogeneity of labelling, i.e., it increased the efflux more for endogenous than for exogenous noradrenaline; moreover it decreased the efflux of 3H-DOPEG, but increased that of 3H-MOPEG. The reserpine-like compound Ro 41284, on the other hand, abolished the consequences of the second type of heterogeneity; it reduced the specific activity of “total efflux” (i.e., of the sum of noradrenaline + DOPEG + MOPEG) to the specific activity of the tissue noradrenaline. The degree of heterogeneity of labelling was reduced after inhibition of monoamine oxidase and also when the tissues were loaded with 2 or 20 μmol/l 3H-noradrenaline. It is proposed that the various “compartments” and “pools” of noradrenaline described in the literature reflect the two heterogeneities described here.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00166959
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  • 19
    Electronic Resource
    Electronic Resource
    Role of nitric oxide formation in the regulation of haemodynamics and the release of noradrenaline and adrenaline (1991)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 344 (1991), S. 720-727 
    Details
    ISSN: 1432-1912
    Keywords: Nitric oxide (EDRF) ; l-NG-Monomethyl-arginine ; Noradrenaline release ; Adrenaline release ; Anaesthetized rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study in the anaesthetized rabbit aimed at determining the role of nitric oxide (NO), the putative endothelium-derived relaxing factor, in the regulation of haemodynamics and the release into plasma of noradrenaline and adrenaline. Specific inhibition of NO formation was achieved by i.v. bolus injection of l-NG-monomethyl-arginine (l-NMMA; 3–100 mg kg−1). Phenylephrine was infused i.v. at constant rates (2.5–20 μg kg−1 min−1) in order to assess baroreflex-mediated changes in release due to direct peripheral vasoconstriction. Rates of noradrenaline and adrenaline release into plasma were determined by the radio-tracer technique. l-NMMA, but not d-NMMA, dose-dependently increased mean arterial pressure and total peripheral vasular resistance, whereas both heart rate and cardiac output decreased concomitantly. The corresponding ED50 values for l-NMMA ranged from 11.2 to 18.5 mg kg−1. Inhibition of NO formation by l-NMMA as well as phenylephrine infusion caused decreases in the plasma clearance of noradrenaline and adrenaline which were correlated with the drug-induced decreases in cardiac output. Both l-NMMA and phenylephrine reduced the rate of noradrenaline release into plasma as they increased total peripheral resistance. Moreover, the curvilinear relationship between these two parameters obtained for l-NMMA was virtually identical to that produced by phenylephrine, indicating that the reduction in noradrenaline release by l-NMMA is mediated solely by the baroreflex. From the l-NMMA-induced maximum inhibition of noradrenaline release, it is concluded that the counter-regulation against peripheral vasodilation by NO accounts for 69% of basal noradrenaline release. The baroreflex-sensitive component of noradrenaline release, as determined by the maximum inhibition of release induced by phenylephrine, amounted to 83% of basal release. l-NMMA also reduced the release into plasma of adrenaline; the maximum inhibition of release was 52%. However, when related to total peripheral resistance, this inhibition of adrenaline release was more pronounced than that induced by phenylephrine, suggesting that the formation of endogenous NO facilitates the release of adrenaline.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00174757
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  • 20
    Electronic Resource
    Electronic Resource
    On the stereoselectivity of the neuronal uptake in the cat's nictitating membrane (1972)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 275 (1972), S. 45-68 
    Details
    ISSN: 1432-1912
    Keywords: Stereoselectivity of Uptake ; Noradrenaline ; Neuronal Uptake ; Neuronal Deamination ; Nictitating Membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Pairs of smooth muscles isolated from the nictitating membrane of the cat were incubated with 1.2 ml of Krebs' solution containing 10 ng/ml of 3H-(±)-noradrenaline for 7.5 min (in the presence of U-0521 to inhibit COMT). Removal of the amine from the bath as well as the appearance of deaminated 3H-catechols in the bath were measured. 2. Pretreatment with reserpine did not affect the rate of removal, while increasing the rate of deamination. The ability of the muscles to retain exogenous amine for one hour was reduced to 12% of normal. 3. A certain fraction of the total production of deaminated 3H-catechols escaped into the medium. For any given duration of incubation this fraction was independent of the concentration of noradrenaline in the medium. On repeated incubation the fraction remained constant. Therefore, reliable estimates of the rate of deamination were obtained with repeated incubations of the same muscle. 4. Sympathetic denervation and/or cocaine revealed that 60% of removal (of which 10% are due to dilution) and 25% of deamination are extraneuronal. 5. For incubations of 7.5 min measured rates of deamination represent initial rates, measured rates of removal do not. 6. Unlabelled (−)- and (+)-noradrenaline were equipotent (ID50=about 1 μM) in inhibiting the deamination of 10 ng/ml of 3H-(±)-noradrenaline. This inhibitory effect must be exerted on neuronal deamination, since extraneuronal deamination (in denervated muscles) was not affected by the addition of unlabelled isomers. 7. It is proposed that, under these experimental conditions, neuronal unptake is the rate limiting step for neuronal deamination, and that neuronal uptake in the cat's nictitating membrane lacks stereoselectivity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00505067
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