metabotropicadj.
/mᵻˌtabəˈtrɒpɪk/, /mᵻˌtabəˈtrəʊpɪk/, U.S. /məˌtæbəˈtrɑpɪk/ Physiology.
Originally: designating a neurotransmitter whose effect is mediated by metabolic alteration (i.e. enzyme activation and second messenger production) rather than direct regulation of ion channels. Now usually: designating or relating to a type of cell receptor whose effect is mediated in this way.
ΚΠ
1978 P. L. McGeer et al. Molecular Neurobiol. Mammalian Brain ii. 141 Neurotransmitters..fall into two categories. The first we refer to as ionotropic because the principal function of the transmitter is to open ionic paths across the postsynaptic membrane... The second we refer to as metabotropic because these neurotransmitters stimulate cyclic nucleotide production and consequent metabolic changes in the postsynaptic cell.
1982 Med. Biol. 60 183 Depending upon the ionotropic or metabotropic characteristics of the cotransmitter, it may be mainly involved in synaptic homeostasis or synaptic plasticity, respectively.
1989 Neurosci. Res. 6 106 Oscillatory responses were mediated by a metabotropic type of Glu receptor which is coupled to a G-protein but not directly to an ionic channel.
1992 Nature 12 Nov. 107/1 The phospholipase C-coupled metabotropic glutamate receptor acts through a G protein to activate phospholipase C and generate the two second messengers inositol trisphosphate and diacylglycerol.
1999 Jrnl. Physiol. 515 385 We conclude that during stimulation of metabotropic purinoceptors, membrane depolarization over the physiological range can stimulate Ca2+ release from intracellular stores in the rat megakaryocyte, a non-excitable cell type.
This is a new entry (OED Third Edition, December 2001; most recently modified version published online March 2022).
<
adj.1978