Neurotensin: A biologically active tridecapeptide isolated from the hypothalamus. It has been shown to induce hypotension in the rat, to stimulate contraction of guinea pig ileum and rat uterus, and to cause relaxation of rat duodenum. There is also evidence that it acts as both a peripheral and a central nervous system neurotransmitter.Receptors, Neurotensin: Cell surface proteins that bind neurotensin with high affinity and trigger intracellular changes which influence the behavior of cells. Neurotensin and neurotensin receptors are found in the central nervous system and in the periphery.QuinolinesPyrazoles: Azoles of two nitrogens at the 1,2 positions, next to each other, in contrast with IMIDAZOLES in which they are at the 1,3 positions.Receptors, Neurotransmitter: Cell surface receptors that bind signalling molecules released by neurons and convert these signals into intracellular changes influencing the behavior of cells. Neurotransmitter is used here in its most general sense, including not only messengers that act to regulate ion channels, but also those which act on second messenger systems and those which may act at a distance from their release sites. Included are receptors for neuromodulators, neuroregulators, neuromediators, and neurohumors, whether or not located at synapses.