What's the difference between lobelia and lobeline?
Lobelia
Definition:
(n.) A genus of plants, including a great number of species. Lobelia inflata, or Indian tobacco, is an annual plant of North America, whose leaves contain a poisonous white viscid juice, of an acrid taste. It has often been used in medicine as an emetic, expectorant, etc. L. cardinalis is the cardinal flower, remarkable for the deep and vivid red color of its flowers.
Example Sentences:
(1) A crude methanolic extract of the leaves of Lobelia inflata exhibited antidepressant activity in mice.
Lobeline
Definition:
(n.) A poisonous narcotic alkaloid extracted from the leaves of Indian tobacco (Lobelia inflata) as a yellow oil, having a tobaccolike taste and odor.
Example Sentences:
(1) Additional experiments demonstrated that lobeline suppressed the conversion of exogenous progesterone to testosterone, but did not affect the conversion of exogenous 17 alpha-hydroxyprogesterone to testosterone.
(2) Bath superfusion of nicotine or the nicotinic stimulants dimethylphenylpiperazinium (DMPP), lobeline, cytisine, tetramethylammonium or suberyldicholine (up to 100 microM) had little or no effect on the extracellular N-wave amplitude, or the membrane potential, input resistance or excitability of olfactory neurones recorded intracellularly.
(3) Interestingly, in the presence of the ganglionic stimulants DMPP (n = 6 slices) or lobeline (n = 5 slices) (10-50 microM), the effects of carbachol or oxotremorine-M were antagonized in a weak competitive-type manner (pA2 values = 5.58 and 5.63 respectively, estimated from Schild plots, constrained to unity slope).
(4) Although ineffective as stimulators of steroidogenesis by themselves, the three nicotinic receptor-selective agonists lobeline, dimethylphenylpiperazinium iodide (DMPP), and phenyltrimethylammonium iodide (PTMA) inhibited FSH-induced progesterone and 20 alpha-hydroxypregn-4-en-3-one production in dose-dependent fashions.
(5) Based on the concentrations in brain and known affinities for high-affinity nicotine binding sites, in vivo tests should show cytisine to be slightly more potent than nicotine and lobeline to have nicotine effects in the doses used.
(6) Lobeline inhibition of hCG-stimulated testosterone production was accompanied by decreases in medium accumulation of 17 alpha-hydroxypregnenolone (75%), 17 alpha-hydroxyprogesterone (85%), dehydroepiandrosterone (50%), and androstenedione (61%); however, the medium content of pregnenolone and progesterone were unchanged.
(7) In addition we found that (-)nicotine, (+)nicotine, and lobeline, but not the nicotine metabolite (-)cotinine nor acetylcholine, were able to displace [3H]dizocilpine ([3H]MK 801) binding in well-washed membranes obtained from rat brain.
(8) The lobeline sulphate seems to produce both in SEEG and hippocampus a shift toward low frequencies and in amygdala a drift toward high frequencies.
(9) Previous work has suggested that cytisine and lobeline are of low potency in producing nicotine-like behavioural effects, despite having some nicotine-like peripheral effects and potently inhibiting the binding of tritiated nicotine to the brain of the rat.
(10) Lobeline failed to produce a nicotine-like discriminative effect, even at doses that greatly reduced overall rates of responding.
(11) One of the most potent antagonists to nicotine was alpha-lobeline.
(12) Bilateral lesions of the paramedian reticular area of medulla destroying the PRN, abolished or reversed the depressor response to electrical stimulation of myelinated fibres of the carotid sinus nerve (CSN), attenuated the depressor response to carotid sinus stretch and augmented the pressor response to chemoreceptor stimulation by lobeline.
(13) Repeated administration of DMPP did not cause a tachphylaxis, however, lobeline and nicotine did induce a tachphylaxis.
(14) The N-cholinomimetic -- lobeline potentiates the evoked response of the brain cortex, whereas the N-cholinolytic -- beta-ethylene-splasmolytin -- depresses it.
(15) The rank order of inhibitory potencies was lobeline greater than DMPP greater than PTMA with IC50 values of 2 X 10(-6) M, 3 X 10(-5) M, and 3 X 10(-4) M, respectively.
(16) The pKa of (-)-lobeline HCl at 25 degrees C is 8.6 (approx), indicating that (-)-lobeline is at least 90% in the protonated form at physiological pH (7.6).
(17) The clastogenicity of lobeline and possible interactions between lobeline and ethyl alcohol were investigated in a mutagen-sensitivity assay on cultures of human lymphoblastoid cell lines.
(18) The effects of ethylketazocine (EKC) administered intraperitoneally and the nicotinic ligands (-)- and (+)-nicotine, (-)-cytisine, (-)-lobeline, and (+)-2-methylpiperidine administered into the 4th ventricle on the latency of the thermally evoked withdrawal reflex of the decerebrate rat were investigated.
(19) Lobeline administration induced an hyperpnea due to both an increase in tidal volume and respiratory rate; this increase in ventilation lasted for about 90 s and was accompanied by a sharp rise in the respiratory peak airflows, especially the expiratory ones.
(20) To determine whether this effect is elicited by other nicotinic agonists found in tobacco, the effects of chronic infusion with nicotine on brain nicotinic receptors were compared with those after anabasine and lobeline.