You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Protein", "Chemical"].

Please return the output as a JSON object of the format: {"Chemical" : ["Dexamethasone", ...], "Protein" : ["BRCA-1", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Characterization of human recombinant alpha(2A)-adrenoceptors expressed in Chinese hamster lung cells using extracellular acidification rate changes.
1. Human alpha(2A)-adrenoceptors heterologously expressed in Chinese hamster lung (CHL) fibroblasts have been characterized pharmacologically using a cytosensor microphysiometer to measure ligand-induced extracellular acidification rate changes. 2. In untransfected CHL cells, noradrenaline had no effect at concentrations up to 100 microM. In alpha(2A)-adrenoceptor transfected cells the rank order of agonist potency was A-54741 (mean pEC(50)=8.96)>dexmedetomidine (8.88)>UK-14304 (8.42)>B-HT 920 (7.05)>noradrenaline (6.92). A-54741, UK-14304 and noradrenaline had the same maximum response while dexmedetomidine and B-HT 920 behaved as partial agonists. 3. The selective alpha(2)-adrenoceptor ligand rauwolscine antagonized acidification rate changes with an affinity independent of the agonist used; the affinity (mean pK(B)) against noradrenaline was 8.43. 4. The selective alpha(1)-adrenoceptor ligands prazosin and doxazosin (each 3 microM) had no effect on noradrenaline responses. 5. Acidification rate changes induced by each agonist were abolished by pre-treatment of cells with pertussis toxin. 6. These data suggest that agonist-induced acidification rate responses in CHL cells transfected with the human alpha(2A)-adrenoceptor are mediated exclusively by the recombinant protein, via pertussis toxin sensitive G(i/o) proteins.
{"Chemical": ["prazosin", "B-HT 920", "doxazosin", "UK-14304", "A-54741", "dexmedetomidine", "rauwolscine", "noradrenaline"], "Protein": ["Human alpha(2A)-adrenoceptors", "alpha(2)-adrenoceptor", "G(i/o) proteins", "alpha(1)-adrenoceptor", "pertussis toxin", "human alpha(2A)-adrenoceptor", "alpha(2A)-adrenoceptors", "alpha(2A)-adrenoceptor"]}