Selectivity of the effects of guanosine-5'-O-(2-thiodiphosphate) on agonist inhibition of the M-current in amphibian sympathetic neurons. 1991

M A Simmons, and R J Mather
Department of Pharmacology, Marshall University, Huntington, West Virginia 25755-9310.

In bullfrog sympathetic neurons, luteinizing hormone-releasing hormone, muscarine, and substance P act as agonists at specific membrane receptors to decrease a potassium current, IM. The receptors are coupled to guanine nucleotide-binding proteins (G-proteins). Whole-cell recordings of IM were made from isolated bullfrog sympathetic neurons to examine the effects of intracellularly applied guanosine-5'-O-(2-thiodiphosphate) (GDP beta S) on agonist inhibition of IM. Successive responses to a given agonist were decreased in the presence of GDP beta s. Subsequent responses to the other agonists were then measured to determine the degree of overlap of the effect of GDP beta S for the different agonists. GDP beta S selectively inhibited successive responses to one agonist such that a subsequent application of a different agonist was still effective. If GDP beta S acts at the level of the G-protein, this suggests that each receptor is coupled to a separate population of G-proteins. Alternatively, GDP beta S may act at the receptor level to block receptor coupling to IM.

UI MeSH Term Description Entries
D007987 Gonadotropin-Releasing Hormone A decapeptide that stimulates the synthesis and secretion of both pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE. GnRH is produced by neurons in the septum PREOPTIC AREA of the HYPOTHALAMUS and released into the pituitary portal blood, leading to stimulation of GONADOTROPHS in the ANTERIOR PITUITARY GLAND. FSH-Releasing Hormone,GnRH,Gonadoliberin,Gonadorelin,LH-FSH Releasing Hormone,LHRH,Luliberin,Luteinizing Hormone-Releasing Hormone,Cystorelin,Dirigestran,Factrel,Gn-RH,Gonadorelin Acetate,Gonadorelin Hydrochloride,Kryptocur,LFRH,LH-RH,LH-Releasing Hormone,LHFSH Releasing Hormone,LHFSHRH,FSH Releasing Hormone,Gonadotropin Releasing Hormone,LH FSH Releasing Hormone,LH Releasing Hormone,Luteinizing Hormone Releasing Hormone,Releasing Hormone, LHFSH
D009116 Muscarine A toxic alkaloid found in Amanita muscaria (fly fungus) and other fungi of the Inocybe species. It is the first parasympathomimetic substance ever studied and causes profound parasympathetic activation that may end in convulsions and death. The specific antidote is atropine.
D009474 Neurons The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM. Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D011892 Rana catesbeiana A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America. Bullfrog,Bullfrogs,Rana catesbeianas,catesbeiana, Rana
D011966 Receptors, LHRH Receptors with a 6-kDa protein on the surfaces of cells that secrete LUTEINIZING HORMONE or FOLLICLE STIMULATING HORMONE, usually in the adenohypophysis. LUTEINIZING HORMONE-RELEASING HORMONE binds to these receptors, is endocytosed with the receptor and, in the cell, triggers the release of LUTEINIZING HORMONE or FOLLICLE STIMULATING HORMONE by the cell. These receptors are also found in rat gonads. INHIBINS prevent the binding of GnRH to its receptors. GnRH Receptors,Gonadoliberin Receptors,Gonadorelin Receptors,Gonadotropin Releasing-Hormone Receptors,LHFSHRH Receptors,LHRH Receptors,Luliberin Receptors,Receptors, GnRH,Receptors, Gonadoliberin,Receptors, Gonadorelin,Receptors, Luliberin,Follicle Stimulating Hormone-Releasing Hormone Receptors,GnRH Receptor,Gonadorelin Receptor,Gonadotropin-Releasing Hormone Receptor,LHRH Receptor,Luteinizing Hormone Releasing Hormone Receptors,Luteinizing Hormone Releasing-Hormone Receptor,Receptor, LHRH,Receptors, Gonadotropin Releasing-Hormone,Receptors, LHFSHRH,Follicle Stimulating Hormone Releasing Hormone Receptors,Gonadotropin Releasing Hormone Receptor,Gonadotropin Releasing Hormone Receptors,Hormone Receptor, Gonadotropin-Releasing,Luteinizing Hormone Releasing Hormone Receptor,Receptor, GnRH,Receptor, Gonadorelin,Receptor, Gonadotropin-Releasing Hormone,Receptors, Gonadotropin Releasing Hormone,Releasing-Hormone Receptors, Gonadotropin
D011976 Receptors, Muscarinic One of the two major classes of cholinergic receptors. Muscarinic receptors were originally defined by their preference for MUSCARINE over NICOTINE. There are several subtypes (usually M1, M2, M3....) that are characterized by their cellular actions, pharmacology, and molecular biology. Muscarinic Acetylcholine Receptors,Muscarinic Receptors,Muscarinic Acetylcholine Receptor,Muscarinic Receptor,Acetylcholine Receptor, Muscarinic,Acetylcholine Receptors, Muscarinic,Receptor, Muscarinic,Receptor, Muscarinic Acetylcholine,Receptors, Muscarinic Acetylcholine
D004553 Electric Conductivity The ability of a substrate to allow the passage of ELECTRONS. Electrical Conductivity,Conductivity, Electric,Conductivity, Electrical
D006153 Guanosine Diphosphate A guanine nucleotide containing two phosphate groups esterified to the sugar moiety. GDP,Guanosine 5'-Diphosphate,Guanosine 5'-Trihydrogen Diphosphate,5'-Diphosphate, Guanosine,5'-Trihydrogen Diphosphate, Guanosine,Diphosphate, Guanosine,Diphosphate, Guanosine 5'-Trihydrogen,Guanosine 5' Diphosphate,Guanosine 5' Trihydrogen Diphosphate
D006160 Guanosine Triphosphate Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety. GTP,Triphosphate, Guanosine
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

Related Publications

M A Simmons, and R J Mather
June 1981, British journal of pharmacology,
M A Simmons, and R J Mather
September 1987, Cellular and molecular neurobiology,
M A Simmons, and R J Mather
June 1984, The Journal of biological chemistry,
M A Simmons, and R J Mather
February 1994, Pflugers Archiv : European journal of physiology,
Copied contents to your clipboard!