Biomaterial Database

Functional kappa-opioid receptors on oxytocin and vasopressin nerve terminals isolated from the rat neurohypophysis. 1988

B G Zhao, and C Chapman, and R J Bicknell

Department of Neuroendocrinology, AFRC Institute of Animal Physiology and Genetics Research, Cambridge, U.K.

Opioids intrinsic to the rat neurohypophysial system act to inhibit secretion from the terminals of magnocellular neurones. Opioid receptors in the neurohypophysis are predominantly of the kappa-subtype and selective kappa-agonists suppress electrically evoked release of oxytocin (OXT) and vasopressin (AVP). We have looked for the presence of functional kappa-receptors on neurohypophysial nerve terminals by examining effects of kappa-agonists on secretion from suspensions of isolated neurohypophysial nerve terminals (neurosecretosomes) retained on filters in a perifusion system. Release of both OXT and AVP evoked by K+-depolarisation was inhibited by the kappa-agonists U-50,488H (34% and 45% respectively) and dynorphin A1-13 (68% and 51% respectively). Inhibition by dynorphin A was only observed in the presence of peptidase inhibitors. The actions of both kappa-agonists were prevented by the opioid receptor antagonist naloxone. The experiments indicate the presence of kappa-receptors on terminals of OXT and AVP neurones. This receptor population is in addition to those previously described on pituicytes and those influencing release of neurohypophysial noradrenaline.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009411	Nerve Endings	Branch-like terminations of NERVE FIBERS, sensory or motor NEURONS. Endings of sensory neurons are the beginnings of afferent pathway to the CENTRAL NERVOUS SYSTEM. Endings of motor neurons are the terminals of axons at the muscle cells. Nerve endings which release neurotransmitters are called PRESYNAPTIC TERMINALS.	Ending, Nerve,Endings, Nerve,Nerve Ending
D010121	Oxytocin	A nonapeptide hormone released from the neurohypophysis (PITUITARY GLAND, POSTERIOR). It differs from VASOPRESSIN by two amino acids at residues 3 and 8. Oxytocin acts on SMOOTH MUSCLE CELLS, such as causing UTERINE CONTRACTIONS and MILK EJECTION.	Ocytocin,Pitocin,Syntocinon
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D010904	Pituitary Gland, Posterior	Neural tissue of the pituitary gland, also known as the neurohypophysis. It consists of the distal AXONS of neurons that produce VASOPRESSIN and OXYTOCIN in the SUPRAOPTIC NUCLEUS and the PARAVENTRICULAR NUCLEUS. These axons travel down through the MEDIAN EMINENCE, the hypothalamic infundibulum of the PITUITARY STALK, to the posterior lobe of the pituitary gland.	Neurohypophysis,Infundibular Process,Lobus Nervosus,Neural Lobe,Pars Nervosa of Pituitary,Posterior Lobe of Pituitary,Gland, Posterior Pituitary,Infundibular Processes,Lobe, Neural,Lobes, Neural,Nervosus, Lobus,Neural Lobes,Pituitary Pars Nervosa,Pituitary Posterior Lobe,Posterior Pituitary Gland,Posterior Pituitary Glands,Process, Infundibular,Processes, Infundibular
D011759	Pyrrolidines	Compounds also known as tetrahydropyridines with general molecular formula (CH2)4NH.	Tetrahydropyridine,Tetrahydropyridines
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D011957	Receptors, Opioid	Cell membrane proteins that bind opioids and trigger intracellular changes which influence the behavior of cells. The endogenous ligands for opioid receptors in mammals include three families of peptides, the enkephalins, endorphins, and dynorphins. The receptor classes include mu, delta, and kappa receptors. Sigma receptors bind several psychoactive substances, including certain opioids, but their endogenous ligands are not known.	Endorphin Receptors,Enkephalin Receptors,Narcotic Receptors,Opioid Receptors,Receptors, Endorphin,Receptors, Enkephalin,Receptors, Narcotic,Receptors, Opiate,Endorphin Receptor,Enkephalin Receptor,Normorphine Receptors,Opiate Receptor,Opiate Receptors,Opioid Receptor,Receptors, Normorphine,Receptors, beta-Endorphin,beta-Endorphin Receptor,Receptor, Endorphin,Receptor, Enkephalin,Receptor, Opiate,Receptor, Opioid,Receptor, beta-Endorphin,Receptors, beta Endorphin,beta Endorphin Receptor,beta-Endorphin Receptors
D004399	Dynorphins	A class of opioid peptides including dynorphin A, dynorphin B, and smaller fragments of these peptides. Dynorphins prefer kappa-opioid receptors (RECEPTORS, OPIOID, KAPPA) and have been shown to play a role as central nervous system transmitters.	Dynorphin,Dynorphin (1-17),Dynorphin A,Dynorphin A (1-17)
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia