Quinpirole

Quinpirole (LY 171555; (-)-LY 141865) is a D2/D3 dopamine receptor agonist and a CaV1.3 calcium channel modulator. Quinpirole normalizes dendritic spine density in dopamine-depleted striatum, upregulates the protein expression of BCL2 and GluR2, downregulates the protein expression of BAX, and delays the onset of seizures. Quinpirole enhances learning and memory, inhibits neuronal apoptosis (apoptosis), and induces anxiety-like, stereotyped, and compulsive behaviors. Quinpirole disrupts prepulse inhibition in rhesus monkeys, enhances the activity of paraventricular thalamic neurons to promote recovery from Isoflurane anesthesia, and alters the composition of the gut microbiota in rats. Quinpirole can be used in research related to dyskinesia, pain, epilepsy, and neurological disorders including anxiety disorder, obsessive-compulsive disorder, and schizophrenia^{[1][2][3][4][5][6][7][8]}. In Vitro:Quinpirole selectively inhibits high-voltage activated calcium channels in dopamine-depleted rat striatal medium spiny neurons, an effect dependent on L-type calcium channel activity^[1]. In Vivo:Quinpirole (0.05-0.1 mg/kg; subcutaneous injection; twice daily for 4 weeks) consistently and significantly inhibits Levodopa (HY-N0304)-induced dyskinesia and prevents the formation of aberrant mushroom-shaped dendritic spines in the dopamine-depleted striatum of Parkinson's disease rats^[1].
Quinpirole (0.1-3 mg/kg; subcutaneous injection) exerts significant analgesic effects in mechanical nociception tests conducted on untreated male Wistar rats, complete Freund's adjuvant (CFA)-induced inflammatory pain models, and chronic constriction injury (CCI)-induced neuropathic pain models, and also produces significant nociceptive enhancement effects^[2].
Quinpirole (intracerebroventricular injection; single dose; 60 minutes prior to Pilocarpine injection) exerts neuroprotective effects on Wistar rats with epilepsy induced by Lithium chloride (HY-Y0649D)-Pilocarpine (HY-B0726A), delays the onset of seizures, improves cognitive function, and regulates the protein expression of GluR2, BAX and BCL2 in hippocampal tissue^[3].
Quinpirole (0.01-3 mg/kg, i.p., 1-4 h prior to sacrifice) dose-dependently decreases the concentrations of epinephrine in the hypothalamus and dopamine metabolites in the cerebral hemispheres of rats; at high doses, it also alters the concentrations of dopamine and norepinephrine in the hypothalamus as well as MHPG sulfate in the brain stem^[4].
Quinpirole (5.5-50 μM; immersion; single 24-hour exposure; at 5 dpf) induces persistent anxiety-like behaviors, stereotypic swimming, and aversive memory impairment in adult zebrafish, with no effect on their social or aggressive behaviors^[5].
Quinpirole (7-70 nM; bilateral intracranial infusion into the nucleus accumbens core; 0.2 μl/min) impairs prepulse inhibition of the acoustic startle reflex^[6].
Quinpirole (0.5 mg/kg, subcutaneous injection, twice weekly for 5 weeks) induces obsessive-compulsive-like behaviors, neuroinflammatory changes, intestinal histological alterations, reduced fecal short-chain fatty acid levels, and intestinal dysbiosis in adult male Wistar rats^[7].
Quinpirole (4 mM via microinjection into the paraventricular nucleus of the thalamus, with a total volume of 0.5 μl and a delivery duration of 2 minutes) significantly shortens the recovery time from Isoflurane (HY-A0134) anesthesia, reduces the cortical burst suppression ratio, and enhances the neuronal activity of the paraventricular nucleus of the thalamus in male C57BL/6J mice^[8].