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:

Pharmacokinetic study of Growth Hormone-Releasing Peptide 6 (GHRP-6) in nine male healthy volunteers.
GHRP-6 is a growth hormone secretagogue that also enhances tissue viability in different organs. In the present work, we studied the pharmacokinetics of this short therapeutic hexapeptide (His-(D-Trp)-Ala-Trp-(D-Phe)-Lys-NH(2,) MW=872.44 Da) in nine male healthy volunteers after a single intravenous bolus administration of 100, 200 and 400 μg/kg of body weight. GHRP-6 was quantified in human plasma by a specific LC-MS method, previously developed and validated following FDA guidelines, using (13)C(3)Ala-GHRP-6 as internal standard (Gil et al., 2012, J. Pharm. Biomed. Anal. 60, 19-25). The Lower Limit of Quantification (5 ng/mL) was reached in all subjects at 12h post-administration, which was sufficient for modeling a pharmacokinetic profile including over 85% of the Area under the Curve (AUC). Disposition of GHRP-6 best fitted a bi-exponential function with R(2) higher than 0.99, according to a mathematic modeling and confirmed by an Akaike index (AIC) lower than that of the corresponding one-compartment model for all subjects. Averaging all three dose levels, the distribution and elimination half-life of GHRP-6 were 7.6 ± 1.9 min and 2.5 ± 1.1h, respectively. These values are coherent with existing data for other drugs whose disposition also fits this model. Dose dependence analysis revealed a noticeable trend for AUC to increase proportionally with administered dose. Atypical GHRP-6 concentration spikes were observed during the elimination phase in four out of the nine subjects studied.
{"Chemical": ["Growth Hormone-Releasing Peptide 6", "GHRP-6", "His-(D-Trp)-Ala-Trp-(D-Phe)-Lys-NH(2,)", "(13)C(3)Ala-GHRP-6"], "Protein": ["Growth Hormone", "growth hormone"]}