76
|
Jokic M, Guillois B, Cauquelin B, Giroux JD, Bessis JL, Morello R, Levy G, Ballet JJ. Fetal distress increases interleukin-6 and interleukin-8 and decreases tumour necrosis factor-alpha cord blood levels in noninfected full-term neonates. BJOG 2000; 107:420-5. [PMID: 10740342 DOI: 10.1111/j.1471-0528.2000.tb13241.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To assess the influence of fetal distress on interleukin-1beta, interleukin-6, interleukin-8 and on tumour necrosis factor-alpha blood levels in noninfected full-term neonates. STUDY DESIGN In a multicentre prospective study, cord blood samples were obtained at time of delivery from 234 noninfected full-term neonates for the purposes of measuring serum levels of interleukin-1beta, interleukin-6, interleukin-8 and tumour necrosis factor-alpha using immunoassays. Women were classified into four groups according to the mode of delivery (vaginal delivery or caesarean section) and the presence or absence of fetal distress. The role of labour was also investigated. RESULTS No significant relationship was found between cytokine cord blood levels and the mode of delivery. Fetal distress was associated with an increase in interleukin-6 (P = 0.01) and interleukin-8 (P < 0.001) levels, and a decrease in tumour necrosis factor-alpha (P < 0.001). Labour was also associated with a significant increase in interleukin-6 and interleukin-8 cord blood levels (P = 0.01 and P < 0.001, respectively). CONCLUSION Fetal distress and labour were each associated with elevated interleukin-6 and interleukin-8 cord blood levels in noninfected full term neonates while only fetal distress was associated with decreased tumour necrosis factor-alpha levels.
Collapse
|
77
|
Crecco M, Vidiri A, Angelone ML, Palma O, Morello R. Retromolar trigone tumors: evaluation by magnetic resonance imaging and correlation with pathological data. Eur J Radiol 1999; 32:182-8. [PMID: 10632555 DOI: 10.1016/s0720-048x(99)00017-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The aim of this study was to evaluate the diagnostic accuracy of magnetic resonance (MR) images to establish both the T stage and the relationships between the tumors and the surrounding structures in retromolar trigone tumors. Twenty-two patients with squamous cell carcinoma of the retromolar trigone were examined by MR with a superconductive scanner operating at 1.5T. The study was performed with spin-echo (SE) T1 and T2 and short SE T1 sequences (TR 180 ms, TE 15 ms) after the administration of 0.2 mmol/kg of gadolinium-DTPA (Gd-DTPA). The mandible was studied with SE T1 weighted sequences and GE sequences. The results were compared with the pathological data on the T stage (TNM classification) and the involvement of the surrounding structures. A positive correlation was found in 19 of the 22 patients with an accuracy of 86%. In one patient, the lesion was classified as T1 by MR which, at surgery, resulted being T4, given the infiltration of the cortical mandible (this infiltration was too limited). In another, the MR showed a T4 lesion because of the presence of low signal intensity in the mandibular marrow with enhancement after the Gd-DTPA injection without cortical erosion, while pathological data revealed a T2 lesion (this signal intensity was secondary to inflammation). In another case, the lesion was classified as T1 by MR which, at surgery, proved to be a T2 lesion. In assessing the involvement of the surrounding structures. MR showed a high accuracy, specificity and sensitivity (> 90%). Five false positive cases were observed: in two because of infiltration of the masseter muscle and in the other three, because of infiltration to the pterigoid muscle, mandible and tonsillar bed, respectively, due to the close contact between the tumors and the surrounding structures. Only one false negative case was observed with infiltration of the mandibular marrow. In evaluating the low signal intensity of the mandibular marrow, the accuracy of MR was 87% the specificity 77% and the sensitivity 100%. In one case, perineural spread along the mandibular nerve was found. In conclusion, MR proved to be highly accurate to study the T stage and examine the relationships between the surrounding structures in cases of retromolar trigone tumors.
Collapse
|
78
|
Morello R, Tonachini L, Monticone M, Viggiano L, Rocchi M, Cancedda R, Castagnola P. cDNA cloning, characterization and chromosome mapping of Crtap encoding the mouse cartilage associated protein. Matrix Biol 1999; 18:319-24. [PMID: 10429950 DOI: 10.1016/s0945-053x(99)00002-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Recently we have isolated and characterized a cDNA coding for a novel developmentally regulated chick embryo protein, cartilage associated protein (CASP). Here we describe the isolation and characterization of the cDNAs coding for the mouse CASP. Comparison of the mammalian putative protein sequence with the chick sequence shows a very high identity overall (51%); in particular the chick protein is homologous to the half amino terminus of the mouse protein. Furthermore, the comparison of the CASP cDNA sequence with sequences of the genebank database confirms our hypothesis that the CASP genes belong to a novel family that also includes genes encoding for some nuclear antigens. In all mouse tissues examined three CASP mRNAs species are detected, whereas in chick tissues a single mRNA is present. Immunohistochemistry studies show that the protein is expressed in all mouse embryonic cartilages. The mouse cartilage associated protein gene (Crtap) was assigned to chromosome 9F3-F4 by fluorescence in situ hybridization.
Collapse
|
79
|
Desson J, Sellin-Peres D, Fauchie C, Morello R. ECPA: première échelle comportementale validée scientifiquement d'évaluation de la douleur chez la personne âgée non communicante. Rev Med Interne 1999. [DOI: 10.1016/s0248-8663(99)80387-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
80
|
Caron A, Gohel C, Mollaret K, Morello R, Chapon F. Study of some components of the cytoskeleton in muscular disorders with nonspecific cytoplasmic bodies. Acta Neuropathol 1999; 97:267-74. [PMID: 10090674 DOI: 10.1007/s004010050984] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To gain a better understanding of the mechanisms involved in the formation of cytoplasmic bodies (CBs), the immunohistochemical and biochemical features of muscle samples with nonspecific CBs were compared to those previously described by our group in cytoplasmic body myopathy (CBM), a congenital disease in which specific CBs are found. Accordingly, we studied nonspecific CBs found in the muscle biopsies of 15 patients with the following diseases: peripheral neuropathy (n = 5), polymyositis (n = 3), myotonic dystrophy (n = 2), sarcoidosis (n = 1), inclusion body myositis (n = 1), hereditary inclusion body myopathy (n = 1), hypothyroidism (n = 1), and muscle atrophy in a patient with multiple brain infarctions (n = 1). Nonspecific inclusions were stained at their periphery by anti-desmin but not by anti-dystrophin antibodies, except in the case of hypothyroidism in which immunostaining was observed with both antibodies. Biochemical studies showed normal amounts of desmin and phosphorylation pattern (the latter data are available for only four patients) as compared to control specimens. Our results differ from those previously reported in CBM, in which CBs were stained by both antidesmin and anti-dystrophin antibodies and in which a hyperphosphorylation of desmin was found. Hypothyroidism is, thus, the only disease in which nonspecific CBs show the same immunostaining pattern as specific CBs from CBM patients. These findings indicate that CBs may result from different mechanisms, and that one of these mechanisms may be shared by CBM and hypothyroidism.
Collapse
|
81
|
Schumann P, Touzani O, Young AR, Morello R, Baron JC, MacKenzie ET. Evaluation of the ratio of cerebral blood flow to cerebral blood volume as an index of local cerebral perfusion pressure. Brain 1998; 121 ( Pt 7):1369-79. [PMID: 9679787 DOI: 10.1093/brain/121.7.1369] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Local cerebral perfusion pressure (CPP), a crucial parameter that should allow a better assessment of the haemodynamic compromise in cerebrovascular diseases, is not currently measurable by non-invasive means. Experimental and clinical studies have suggested that the regional ratio of cerebral blood flow to cerebral blood volume (CBF:CBV), as measured by PET, represents an index of local CPP in focal ischaemia. The present study was designed to evaluate further the reliability of the CBF:CBV ratio during manipulations of CPP by deliberately varying mean arterial pressure (MAP) in the anaesthetized baboon. Cortical CBF, CBV, cerebral metabolic rate for oxygen (CMRO2) and oxygen extraction fraction were measured by PET using the (15)O steady-state technique in 10 anaesthetized baboons. Five baboons (Group A) underwent four PET examinations at different levels of MAP: base line (101 +/- 6 mmHg) followed by moderate hypotension (58 +/- 3 mmHg) and, in a separate experiment, minor hypotension (72 +/- 3 mmHg) followed by profound hypotension (34 +/- 5 mmHg). Trimetaphan was used to lower MAP to minor and moderate levels while profound hypotension was achieved by the combined effects of trimetaphan and lower-body negative pressure. Five other baboons (Group B) were subjected to hypertension (121 +/- 2 mmHg) induced by metaraminol and were compared with their base line state (81 +/- 10 mmHg). While CBF displayed significant changes with varying MAP, i.e. decrease and increase with hypotension and hypertension, respectively (-11% from base line to moderate hypotension compared with -20%, from minor to profound hypotension and +31% from base line to hypertension), CBV was more variable and did not significantly change, except with profound hypotension when the increase was significant (+13%). The CBF:CBV ratio decreased significantly at all stages of hypotension (-21 and -31%) and was significantly increased during hypertension (+30%). Importantly, the CBF:CBV ratio demonstrated a significant correlation with MAP (rho = 0.78, Spearman's rank correlation coefficient, P < 0.01). No major changes in CMRO2 were noted during either hypotension or hypertension. Our results demonstrate that, under physiological conditions, cortical CBF:CBV is significantly correlated with CPP, itself a function of MAP. In the investigated range of MAP, the relationships between CBF:CBV and MAP appear to be linear. These findings further argue for the reliability of CBF:CBV as an index of CPP in situations where increases or decreases of MAP without superimposed changes in cerebrovascular tone are encountered, and they confirm the potential usefulness of this regional ratio for clinical investigations and management in cerebrovascular diseases.
Collapse
|
82
|
Reznik Y, Benhaïm A, Morello R, Herlicoviez M, Ballet JJ, Mahoudeau J. High frequency of IgG antagonizing follicle-stimulating hormone-stimulated steroidogenesis in infertile women with a good response to exogenous gonadotropins. Fertil Steril 1998; 69:46-52. [PMID: 9457931 DOI: 10.1016/s0015-0282(97)00430-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To investigate the presence of FSH-blocking IgG in infertile women. DESIGN Retrospective study. Sera from patients and controls were processed for IgG purification, and purified IgG were tested at various concentrations for their ability to inhibit the recombinant human FSH-induced P production in vitro by human granulosa cells. SETTING Departments of Endocrinology, and Obstetrics and Gynecology, University of Caen. PATIENT(S) Fifty-seven infertile women including 14 women with premature ovarian failure (POF), 29 women with a poor response to IVF-ET, and 14 women with a good response to IVF-ET. Controls consisted of 22 healthy age-matched women. INTERVENTION(S) IVF-ET allowed human granulosa cell pooling and culture for FSH bioassay. MAIN OUTCOME MEASURE(S) Inhibition by purified IgG of the in vitro recombinant human FSH-induced P production by human granulosa cells. RESULT(S) Blocking IgG were identified in only 3 of 14 POF and in 2 of 29 women with a poor response to IVF-ET. In contrast, IgG from women with a good response to IVF-ET inhibited significantly P production, and blocking IgG were detected in 85% women with a good response to IVF-ET. CONCLUSION(S) This study identified FSH-blocking IgG in a high proportion of women with a good response to IVF-ET. The significance of this remains questionable.
Collapse
|
83
|
Castagnola P, Gennari M, Morello R, Tonachini L, Marin O, Gaggero A, Cancedda R. Cartilage associated protein (CASP) is a novel developmentally regulated chick embryo protein. J Cell Sci 1997; 110 ( Pt 12):1351-9. [PMID: 9217321 DOI: 10.1242/jcs.110.12.1351] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
A subtracted cDNA library was generated to identify cDNAs specific for chondrocyte mRNAs preferentially expressed at the hypertrophic stage with respect to early differentiation stages. The characterization of a cDNA isolated from this library that hybridizes with a 1.8 kb mRNA is described here. This mRNA is expressed at extremely low levels in dedifferentiated chondrocytes cultured in adherent conditions, at very low levels in differentiating chondrocytes and at very high levels in hypertrophic chondrocytes cultured in suspension conditions. In the developing chick embryo this mRNA is detectable in RNAs extracted from several other tissues besides cartilage. The described cDNA contains a complete open reading frame coding for a polypeptide of about 33 kDa. Homology searches with known cDNA and protein sequences have revealed that the chicken protein is related to the amino-terminal half of two mammalian nuclear antigens. By immunohistochemistry with specific rabbit antisera a strong signal was detected in the cartilage extracellular matrix of selected regions of the developing skeleton. Because of this localization of the antigen we named this protein cartilage associated protein (hereafter referred to as CASP).
Collapse
|
84
|
Vlasenko A, Petit-Taboué MC, Bouvard G, Morello R, Derlon JM. Comparative quantitation of cerebral blood volume: SPECT versus PET. J Nucl Med 1997; 38:919-24. [PMID: 9189142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
UNLABELLED Quantification of cerebral blood volume (CBV) measured by SPECT has been used for evaluation of cerebral hemodynamics in patients with cerebrovascular diseases. The accuracy of such quantification, however, has not been validated with PET. METHODS CBV was assessed using SPECT and in vitro 99mTc-labeled red blood cells and PET with the 15O steady-state inhalation method and C15O. In 23 patients with carotid artery disease, we measured hemispheric (including cortical and subcortical areas) CBV, and in 11 patients, we measured regional CBV in small cortical regions. We further evaluated the interhemispheric and inter-regional asymmetry of CBV with both methods. RESULTS Quantitative values of both hemispheric and regional CBV measured by SPECT were significantly correlated with those measured by PET in the same patients. There was a significant correlation between the side-to-side asymmetry of CBV for both methods. CONCLUSION This study demonstrates usefulness and the accuracy of SPECT for quantitative CBV assessment in comparison with the less widely available PET procedures.
Collapse
|
85
|
Schumann P, Touzani O, Young AR, Verard L, Morello R, MacKenzie ET. Effects of indomethacin on cerebral blood flow and oxygen metabolism: a positron emission tomographic investigation in the anaesthetized baboon. Neurosci Lett 1996; 220:137-41. [PMID: 8981492 DOI: 10.1016/s0304-3940(96)13210-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The aim of this study was to clarify the controversy about the effects of indomethacin on the coupling of cerebral blood flow (CBF) to cerebral oxygen metabolism (CMRO2). CBF, blood volume (CBV), oxygen extraction fraction (OEF) and CMRO2 were measured by positron emission tomography (PET) in five anaesthetized baboons before and during an i.v. administration of indomethacin (bolus 20 mg/kg followed by perfusion 10 mg/kg.h). Administration of indomethacin resulted in a marked and homogenous decrease of CBF in every region analysed (-28% to -40%) and a moderate reduction in CBV (-8% to -16%). In contrast, CMRO2 displayed a small increase in thalamus and pons (+10% and +13%, respectively). OEF increased greatly in all structures studied (+59% to +96%). These findings show that the potent cerebrovascular effects of indomethacin are not related to a decrease in CMRO2 as measured through the use of PET.
Collapse
|
86
|
Morello R, Riou M, Morel P, Thouin A. [Isolation rooms in the psychiatric environment]. Rev Epidemiol Sante Publique 1996; 44:214-20. [PMID: 8766980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
To date, there has been no survey concerning psychiatric isolation rooms in France. We conducted a mail survey in 1993 involving all adult psychiatric care catchment areas covering the French departments. The survey revealed an estimated number of 1560 isolation rooms. Isolation rooms were considered as absolutely necessary in all the departments but also as an unsatisfactory solution by one-third of them. Isolation rooms were usually small and poorly adapted to efficient patient surveillance. Furthermore, equipment was often inadequate, particularly for noise and fire protection. A serious accident (fire, suicide, escape) was reported by large number of departments. The rooms were used for agitated psychotic (84%) and psychopathic (16) people. Although requested by the physician, but also in some cases by the patient, conditions of use and design of isolation rooms may be dangerous both for the patient and the nursing staff. Financial investment devoted to isolation rooms varies greatly and there is no specific control over the number of installation. Construction must comply with precise specifications defined in co-ordination with the experts involved.
Collapse
|
87
|
Reznik Y, Pousse P, Herrou M, Morello R, Mahoudeau J, Drosdowsky MA, Fradin S. Postprandial lipoprotein metabolism in normotriglyceridemic non-insulin-dependent diabetic patients: influence of apolipoprotein E polymorphism. Metabolism 1996; 45:63-71. [PMID: 8544779 DOI: 10.1016/s0026-0495(96)90201-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Non-insulin-dependent diabetes mellitus (NIDDM) is associated with postprandial lipoprotein clearance defects that are correlated with the fasting hypertriglyceridemia widely observed in NIDDM patients. The aim of this study was to determine if such postprandial disturbances are found in NIDDM patients strictly normotriglyceridemic in the fasting state, and if the apolipoprotein E (apo E) polymorphism influences postprandial metabolism of intestinally derived lipoproteins. The vitamin A-fat loading test was used in 18 normotriglyceridemic NIDDM patients and seven normotriglyceridemic obese controls, and postprandial triglyceride (TG) and retinyl palmitate (RP) concentrations were evaluated in total plasma, and in the chylomicron (Sf > 1,000) and nonchylomicron (Sf < 1,000) fractions isolated by ultracentrifugation. NIDDM patients exhibited an amplified response of both TG and RP as compared with obese controls in the three fractions. Incremental TG response to the oral fat load was strongly correlated with fasting TG level (r = .80, P < .0001) in the whole study population. Postprandial lipoprotein profiles were distinguished in NIDDM patients according to apo E phenotype: despite normal fasting TG levels in E3/3 (n = 6), E2/3 (n = 6), and E3/4 (n = 6), postprandial RP response was twofold to threefold higher in E2/3 and E3/4 patients than in the common E3/3 phenotype. Contrasting lower postprandial TG increment and lower fasting and postprandial high-density lipoprotein (HDL) and HDL3 cholesterol levels were observed in E3/4 versus E3/3 patients, possibly reflecting modifications in lipid content of the postprandial lipoproteins driven by a differential lipid transfer activity depending on apo E isoform. These data indicate an enhanced postprandial lipemia in normotriglyceridemic NIDDM patients, and demonstrate the influence of apo E polymorphism on their lipoprotein clearance. Postprandial alterations of lipoprotein remnants may thus accelerate atherogenesis even in normotriglyceridemic NIDDM patients.
Collapse
|
88
|
Benoist P, Legeay G, Morello R, Poncin-Epaillard F. Preparation de surfaces de polymeres par plasma froid pour metallisation par galvanochimie. Eur Polym J 1992. [DOI: 10.1016/0014-3057(92)90280-f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
89
|
Puccia E, Maiorca A, Morello R, Calderaro G. Cyclic nucleotides in the amphibian discoglossus pictus during embryonic development. I. Cyclic nucleotides determination. ACTA EMBRYOLOGIAE ET MORPHOLOGIAE EXPERIMENTALIS ("HALOCYNTHIA" ASSOCIATION") 1980; 1:157-62. [PMID: 6277124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
90
|
Puccia E, Mansueto C, Morello R, Calderaro G. Cyclic nucleotides in ascidian embryonic development. I. Cyclic nucleotides determination. ACTA EMBRYOLOGIAE ET MORPHOLOGIAE EXPERIMENTALIS ("HALOCYNTHIA" ASSOCIATION") 1980; 1:137-42. [PMID: 6277123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
91
|
Abstract
Alkyl and aromatic guanidines interact strongly with the tetrodotoxin (TTX)- receptor site in eel electroplaque membranes, showing competition with TTX. That these guanidines could be useful as highly reversible small molecular weight blockers of Na+ currents is therefore suggested. We have investigated the mechanisms of interaction of one of these derivatives, nonylguanidine, by studying its effects on Na+ currents in squid giant axons using voltage clamp techniques. Although nonylguanidine competed with TTX for binding to eel electroplaque membrane fragments (Ki = 1.8 X 10(-5) M), it reversibly blocked both inward and outward Na+ currents in intact axons only if applied to the interior. In axons with the Na+ inactivation removed by papain nonylguanidine produced a time-dependent block very similar to that reported for strychnine and pancuronium. The reduction of steady-state currents in these axons was also voltage-dependent, with increasing block observed with increasing step depolarization. These results suggest that nonylguanidine binds to a site accessible from the axoplasmic side of the channel, simulating Na+ inactivation in papain-treated axons and competing with the normal inactivation process in untreated axons. The competition between internal nonylguanidine and external TTX may result from perturbation by the positively charged nonylguanidine of the TTX-binding site from within the channel itself.
Collapse
|
92
|
Guy HR, Dekin MS, Morello R. Effect of denervation on the permeability of acetylcholine-activated channels to organic cations. JOURNAL OF NEUROBIOLOGY 1977; 8:491-506. [PMID: 903767 DOI: 10.1002/neu.480080509] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Experiments were perfomed on chronically denervated frog sartorius muscles to determine the permeability of the acetylcholine-activated channels to organic cations. The membrane voltage response to bath-applied acetylcholine was measured with the moving electrode when the muscles were bathed in normal Ringer and in Ringer in which all of the Na+ had been replaced with an organic cation. The magnitude of the maximum voltage response was used to estimate the permeability of the channel to the organic cation. These results were compared with those which have been reported for innervated frog sartorius muscles (Maeno, Edwards, and Anraku, 1977). It is concluded that the permeability to a wide range of organic cations is virtually identical for the extrajunctional channels which develop following denervation and the channels with are localized at the junctional region of innervated muscles.
Collapse
|