(n.) An organic base, especially one of a class of substances occurring ready formed in the tissues of plants and the bodies of animals.
Example Sentences:
(1) Thus, alkaloid and insecticide modifications share many features but differ in how much the conducting properties of the pore are changed and whether the channel can close reversibly while the toxin remains bound.
(2) A clear structure-mutagenicity relationship was observed in a series of aporphine alkaloids (aporphine, dehydroaporphine, 7-oxoaporphine and 4,5-dioxoaporphine), and 10,11-non-substituted aporphines were suggested to exert their mutagenicity through metabolic activation of the 10,11 positions, possibly as the 10,11-epoxides.
(3) A radioactive, photoactive Vinca alkaloid, N-(p-azido-[3,5-3H]-benzoyl)-N'-beta-aminoethylvindesine [( 3H]NABV) with pharmacological and biological activities similar to vinblastine was synthesized and used to identify specific Vinca alkaloid macromolecular interactions in calf brain homogenate by photoaffinity labeling.
(4) The comparative metabolism of the pyrrolizidine alkaloid (PA) senecionine was studied in vitro in incubations of rat, guinea pig, cow, horse, and sheep hepatic microsomes.
(5) They also displayed negative correlation between activities of protein-inhibitors and the total content of protein and alkaloids.
(6) Methods have been reviewed for alkylating agents, platinum compounds, antitumour antibiotics, antimetabolites, alkaloids, suramin, 1-hydroxy-3-amino-propylidene-1,1-bisphosphonate and tamoxifen.
(7) The resistant strains exhibited cross resistance to anthracycline antibiotics, vinca alkaloids, actinomycin D, colchicine.
(8) In mice treated with cepharanthine (Cepha), a biscoclaurine alkaloid, the number of T cells was increased in the parathymic lymph nodes (PtLNs) which are considered to be the specialized lymph nodes in local differentiation of T cells.
(9) The alkaloid tubulosine inhibits the process of peptide chain elongation by eukaryotic polysomes by specifically preventing the elongation-factor-2-dependent step of translocation.
(10) Cultured roots of Stephania cepharantha, which are rich sources of bisbenzylisoquinoline alkaloids, were fed 14C-labelled tyrosine, tyramine or dopamine.
(11) As a possible mechanism underlying the alterations of DRP, the functional consequences of atrophic changes of primary central afferent terminals are being discussed in terms of the close correlation between structure and function and the possible inferences of the electrophysiological reaction to the therapeutic application of Vinca alkaloids in the iontophoretic treatment of chronic intractable pain.
(12) The poisonous principles in tansy ragwort are pyrrolizidine alkaloids, which cause gradual alteration and necrosis of liver cells with replacement by fibrous tissue.
(13) In this study, the roots of Tabernaemontana heyneana Wall were examined and the isolation and identification of additional indole alkaloids and some pharmacological properties of coronaridine are described.
(14) The area ratios of four alkaloids (tropacocaine, norcocaine, cis-cinnamoylcocaine, and trans-cinnamoylcocaine) to cocaine are calculated for each sample.
(15) The main drugs with specific action on migraine include ergot alkaloids (ergotamine, dihydroergotamine), agonists (sumatriptan) or partial agonists (methysergide) at a specific subtype of 5-HT1-like receptors, beta-adrenoceptor antagonists (propranolol, metoprolol), calcium antagonists (flunarizine) and anti-inflammatory agents (indomethacin).
(16) Effects of solution variables on the binding and self-association explain the wide variation of reported apparent binding constants for Vinca alkaloids to tubulin.
(17) The concomitance of five previously reported trans-2,5-dialkyl-pyrrolidines along with small amounts of the cis isomers and N-methyl analogues makes the venom of M. indicum the most qualitatively diverse blend of alkaloids reported from an ant to date.
(18) Strong enhancement of delayed-type hypersensitivity (DTH) was observed after treatment with the active cyclophosphamide (CY) derivative Z 7557 or the plant alkaloid VP-16 at the site of sensitization.
(19) A total alkaloid and two purified alkaloid extracts of Alangium Vitiense were revealed by our experimental screening to be oncostatic on L1210 leukemia and two other lymphoid neoplasias in Mice.
(20) Possible mechanisms underlying these effects of insecticides on alkaloid-dependent uptake are discussed in light of a qualitative model formulated from these results and previous biochemical and electrophysiological studies.
Hyoscyamine
Definition:
(n.) An alkaloid found in henbane (Hyoscyamus niger), and regarded as its active principle. It is also found with other alkaloids in the thorn apple and deadly nightshade. It is extracted as a white crystalline substance, with a sharp, offensive taste. Hyoscyamine is isomeric with atropine, is very poisonous, and is used as a medicine for neuralgia, like belladonna. Called also hyoscyamia, duboisine, etc.
Example Sentences:
(1) They received either glycopyrronium, or 1-hyoscyamine in a sustained-release form, or inert tablets for one year.
(2) The long-lasting decrease and increase in sinus rate were abolished by 1-hyoscyamine and propranolol respectively, and both were reduced by tetrodotoxin.
(3) Two colorimetric micromethods are described for the determination of atropine-hyoscyamine and hyoscine (scopolamine), using p-dimethylaminobenzaldehyde and citric acid-acetic anhydride as the color reagents.
(4) Its use in separating optical isomers of dl-scopolamine, dl-hyoscyamine, dl-homatropine, and dl-cocaine is discussed.
(5) Phenthonium (10-50 microM), a quaternary derivative of 1-hyoscyamine, increases the frequency of miniature end-plate potentials (2-5 fold) and blocks the nicotinic receptor-ionic channel in skeletal muscles.
(6) A new method for separation and determination of four important tropane alkaloids (hyoscyamine, scopolamine, anisodamine and anisodine) in crude drugs by micellar HPLC was developed.
(7) Columns (10 cm) filled with silical gel (particle size, 5 mum; pore size, 1000 A) show the best performance in the separation of hyoscyamine, scopolamine and ergotamine as picrate ion-pairs.
(8) Except for the more frequent reporting of dry mouth with L-hyoscyamine, side effects were not different among the groups.
(9) Diastereomeric urethane derivatives of atropine (d,l-hyoscyamine) and l-hyoscyamine were prepared by reacting the alkaloids with (-)-1-phenylethylisocyanate.
(10) In a randomized, double-blind, placebo controlled crossover study, the pharmacokinetics and some clinically important pharmacodynamic effects of intramuscular atropine (dl-hyoscyamine) were studied in 6 healthy male volunteers.
(11) This study compared the effects of glucagon (N = 48), L-hyoscyamine (N = 43), and placebo (N = 45) on gastric and duodenal distension, mucosal coating, and patient tolerance.
(12) L-Hyoscyamine provided gastric and duodenal images equal in quality to glucagon.
(13) The plasma concentrations of l-hyoscyamine were analyzed by radioreceptor assay (RRA) and the plasma concentrations of dl-hyoscyamine by radioimmunoassay (RIA).
(14) A simplified method for the quantitative analysis of hyoscyamine hydrobromide or atropine in Belladonna Tincture USP is described.
(15) This might at least partly explain the advantage of combining 1-hyoscyamine and an oxime with diazepam in intoxications with anticholinesterases.
(16) Tropine (tropan-3 alpha-ol) is an intermediate in the formation of hyoscyamine.
(17) The concentrations of d-hyoscyamine calculated from the dl- and l-hyoscyamine concentrations reached maximum between 1 and 2 h after drug injection.
(18) The renal excretion of l-hyoscyamine occurred mostly in 6 h (34% of the dose) and no conjugated drug forms were detected.
(19) By injecting the optical antipodes of atropine, D- and L-hyoscyamine separately in mice and following their kinetics in different parts of the brain it was possible to separate the specific receptor binding of the active antipode L-hyoscyamine from that of the inactive antipode D-hyoscyamine, representing unspecific binding.
(20) The assay is more selective for scopolamine (percent cross-reactions for hyoscyamine = 0.21%, 6-hydroxy-hyoscyamine = 0.17%) than previously reported immunoassays.