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: ["Disease", "Chemical"].

Please return the output as a JSON object of the format: {"Chemical" : ["Naloxone", ...], "Disease" : ["Hypotensive", ...]}. 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:

Receptor mechanisms of nicotine-induced locomotor hyperactivity in chronic nicotine-treated rats. Rats were pretreated with saline or nicotine (1.5 mg/kg per day) by subcutaneously implanting each animal with an Alzet osmotic mini-pump which continuously released saline or nicotine for 1, 5 and 14 days. At the end of each pretreatment period, animals were used for (i) determining their locomotor response to acutely injected nicotine (0.2 mg/kg, s.c.) and (ii) measuring the density of L-[3H]nicotine and [3H]spiperone binding sites in the striatum. We observed no changes in nicotine-induced locomotor response, striatal L-[3H]nicotine and [3H]spiperone binding in the animals pretreated with nicotine for 1 day. In rats which were pretreated with nicotine for 5 days, there was a significant increase in the nicotine-stimulated locomotor response which was associated with an increase in the number of L-[3H]nicotine binding sites and also with an elevated dopamine (DA) level in the striatum. The number of striatal [3H]spiperone binding sites was not affected. In animals pretreated with nicotine for 14 days, the nicotine-induced locomotor response remained to be potentiated. However, this response was correlated with an elevated number of striatal [3H]spiperone binding sites, whereas the number of striatal L-[3H]nicotine binding sites and the striatal DA level were normal. These results suggest that chronic nicotine-treated rats develop locomotor hyperactivity in response to nicotine initially due to increases of both the density of nicotinic receptors and DA concentration, followed by inducing DA receptor supersensitivity in the striatum.
{"Chemical": ["DA", "spiperone", "nicotine", "dopamine"], "Disease": ["locomotor hyperactivity"]}