What's the difference between alkaloid and nicotine?

Alkaloid


Definition:

  • (a.) Alt. of Alkaloidal
  • (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.

Nicotine


Definition:

  • (n.) An alkaloid which is the active principle of tobacco. It is a colorless, transparent, oily liquid, having an acrid odor, and an acrid burning taste. It is intensely poisonous.

Example Sentences:

  • (1) testosterone, fentanyl, nicotine) may ultimately be administered in this way, important questions pertaining to pharmacology (tolerance), toxicity (irritation, sensitisation) and dose sufficiency (penetration enhancement) remain.
  • (2) The effect of the peptides on carbachol-induced 22Na+ flux into BC3H-1 cells, which contain nicotinic acetylcholine receptors on their surfaces, was measured.
  • (3) The compounds 1-3 in reaction with nicotine aldehyde or p-chlorobenzaldehyde were transformed into appropriate anilides of 2,3-epoxypropionic acid 4-9.
  • (4) The data suggest that the hypothalamic beta-E containing neurons were unable to adapt to nicotine's repeated effects on this system.
  • (5) The marine natural product lophotoxin has produced a non-reversible antagonism of parasympathetic and sympathetic functions that are known to be mediated by C6 sub-type nicotinic receptors.
  • (6) Stuart Forman and Keith Miller describe the physiological, biophysical and molecular biological evidence pointing to the location of a discrete allosteric site on the nicotinic acetylcholine receptor at which local anesthetics act.
  • (7) These impairments were seen in animals of both sexes, a finding which challenges the view that only females prenatally treated with nicotine show deficits in maze learning.
  • (8) Treatment with oxotremorine caused down-regulation of muscarinic receptors, while treatment with nicotine caused up-regulation of nicotinic receptors.
  • (9) Twelve young male smokers each participated in four conditions on 4 separate days: stress + nicotine, stress + placebo (stress alone), rest + nicotine (nicotine alone), and rest + placebo.
  • (10) More recently, it has been reported that individuals strongly reactive to psychological stress are also strongly reactive to nicotine.
  • (11) The beneficial effect of nicotine has been seen after both acute and chronic administration.
  • (12) At a concentration of 10 microM, tetraamine 4 did not affect histamine and 5-hydroxytryptamine receptors of guinea pig ileum or alpha-adrenoreceptors of guinea pig atria whereas it inhibited postsynaptic alpha-adrenoreceptors of rat vas deferens with a -log K value of 5.23 and nicotinic receptors of frog rectus abdominis with an IC50 value of 0.23 microM.
  • (13) With an 80% carbohydrate diet, the rate of catabolism from the plasma compartment rose by a mean of 39.1%; with nicotinic acid treatment, it fell by 42.2%.
  • (14) The inhibitory action of nicotine on plasma extravasation may contribute, in part, to the reported increased severity of arthritis in individuals who smoke.
  • (15) The inhibitory response was not decreased by treatment with atropine, hexamethonium, yohimbine or naloxone, suggesting that muscarinic, nicotinic, alpha 2 adrenergic or opiate receptors were not being stimulated.
  • (16) Dose-response curves to acetylcholine (ACh) and nicotine were established for pairs of tissues with and without epithelium, each pair receiving only one dose of nicotine.
  • (17) The effect of nicotine on the nervous system during rapid smoking of two calibrated cigarettes was measured in twenty subjects: light, medium, heavy and non-smokers, across the changes of a number of electrophysiological variables and in different situations.
  • (18) Tremors induced by chemical agents (nicotine, zinc and tremorine) were markedly inhibited by HA-966.
  • (19) Magnesium (Mg) deficiency, nicotine, and high dietary cholesterol are contributing factors that accentuate adverse effects of vitamin D.
  • (20) Orthodromic action potentials were initiated by excitatory postsynaptic potentials and mediated by nicotinic receptors.

Words possibly related to "nicotine"