<prompt> Adrenaline, noradrenaline and dopamine act throughSingle pass receptorsFour pass receptorsSeven pass receptorLigand gated channel  <response>: C i.e. Seven pass - receptorCatecholamines epinephrine, norepinephrine and dopamine act through G protein coupled receptors GPCRs, which span the cell membrane 7 times; hence also referred to as seven pass seven helix or serpentine receptors. Catecholamines adrenaline, noradrenaline dopamine act through G protein coupled receptors. al adrenargic catecholamine use phospholipid CIP3 ?DAG and az adrenergic catecholamines use C-AMP adenyl cyclase second messenger system. Hetrotrimeric GTP binding proteins G? proteins are cell membrane proteins that have seven trans membrane segments that loop pass in out of cell membraneQ. serpentine protein Cytoplasmic tail is coupled to GTP that has 3 pa trimeric - a, 13, y subunits. Ligands for GPCRs NeurotransmittersTachykininsArachidonic Acid- AdrenalineQ- NoradrenalineQ- DopamineQ- Neurokinin A- Neuropeptide K- Substance Pderivatives- Thromboxane A2- 5-Hydroxytryptamine Other Ligands- HistaminePeptides- Endothelins- Acetylcholine ACH- Angiotensis II- Platelet activating factor- Adenosine- Arginine- Cannabinoids- Opioidsvasopressin- OdorantsGlycoprotein - Hormones- Oxytocin- Light- LH, FSH, hCG- TSH- VIP, PTH, GRP,TRH- Tastants 