Modulation of protein macromolecules controlling muscle membrane conductances: The acetylcholine receptor and the voltage-gated sodium channel of muscle membrane are the best characterized of the proteins controlling membrane conductances and are, thus, excellent models to study basic biophysical phenomena. Preliminary experiments indicate that cholinergic channel parameters are modified in chick myocytes grown in cholesterol-enriched media. We will use patch clamp methods to measure receptor channel conductance and open time parameters and correlate them with cholesterol to phospholipids ratios in these myocytes membranes. We have also observed that extracts from ciguatoxic barracuda, one of the tropical fish implicated in human intoxication with ciguatera, inhibit the action of acetylcholine in the frog neuromuscular junction. Experiments are proposed to study the mechanism of this inhibition in the frog motor endplate. Using chromatographically purified ciguatoxic fractions we will intracellularly record membrane potentials and measure sodium currents under patch clamp. Patches of chick myocyte membrane will be clamped to assay effect of these fractions on acetylcholine receptor properties. These experiments are designed to bring us closer to an understanding of the mechanisms by which these macromolecules control membrane excitability. Minority students participating in these studies will learn modern electrophysiological methods and tissue culture techniques and will be able to realize how basic research may provide evidence on disease processes such as arteriosclerosis and ciguatera fish intoxication.

Project Start
Project End
Budget Start
Budget End
Support Year
23
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of Puerto Rico Rio Piedras
Department
Type
DUNS #
City
San Juan
State
PR
Country
United States
Zip Code
00931
Ramírez-Camejo, Luis A; Maldonado-Morales, Génesis; Bayman, Paul (2017) Differential Microbial Diversity in Drosophila melanogaster: Are Fruit Flies Potential Vectors of Opportunistic Pathogens? Int J Microbiol 2017:8526385
Morales-Rivera, Keyla F; Piñero Cruz, Dalice M; Prieto, Jose A (2017) Crystal structure of (-)-(S)-4-[(2S,3S,4S,Z)-3-hydroxy-4-methyl-hept-5-en-2-yl]-1,3-dioxolan-2-one. Acta Crystallogr E Crystallogr Commun 73:1070-1072
García-Arriaga, Marilyn; Acosta-Santiago, Maxier; Cruz, Antony et al. (2017) Probing the Limits of Supramolecular G-Quadruplexes Using Atomistic Molecular Dynamics Simulations. Inorganica Chim Acta 468:209-222
Huang, Qing; Quiñones, Edwin (2016) A spectroscopic method to determine the activity of the restriction endonuclease EcoRV that involves a single reaction. Anal Biochem 497:103-5
Mège, Pascal; Schizas, Nikolaos V; Reyes, Joselyd García et al. (2015) Genetic seascape of the threatened Caribbean elkhorn coral, Acropora palmata, on the Puerto Rico Shelf. Mar Ecol (Berl) 36:195-209
Morales-Rivera, Amarilys; Hernández-Burgos, Mayté M; Martínez-Rivera, Arlene et al. (2014) Anxiolytic effects of oxytocin in cue-induced cocaine seeking behavior in rats. Psychopharmacology (Berl) 231:4145-55
Ramírez-Camejo, Luis A; Torres-Ocampo, Ana P; Agosto-Rivera, José L et al. (2014) An opportunistic human pathogen on the fly: strains of Aspergillus flavus vary in virulence in Drosophila melanogaster. Med Mycol 52:211-9
Galindo-Cardona, Alberto; Acevedo-Gonzalez, Jenny P; Rivera-Marchand, Bert et al. (2013) Genetic structure of the gentle Africanized honey bee population (gAHB) in Puerto Rico. BMC Genet 14:65
Santiago-Rodriguez, Tasha M; Rivera, Jessica I; Coradin, Mariel et al. (2013) Antibiotic-resistance and virulence genes in Enterococcus isolated from tropical recreational waters. J Water Health 11:387-96
Pantoja-Feliciano, Ida Gisela; Clemente, Jose C; Costello, Elizabeth K et al. (2013) Biphasic assembly of the murine intestinal microbiota during early development. ISME J 7:1112-5

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