(n.) The soft spongy substance in the center of the stems of many plants and trees, especially those of the dicotyledonous or exogenous classes. It consists of cellular tissue.
(n.) The spongy interior substance of a feather.
(n.) The spinal cord; the marrow.
(n.) Hence: The which contains the strength of life; the vital or essential part; concentrated force; vigor; strength; importance; as, the speech lacked pith.
(v. t.) To destroy the central nervous system of (an animal, as a frog), as by passing a stout wire or needle up and down the vertebral canal.
Example Sentences:
(1) Finally, fosinopril had no effect on the pressor or chronotropic effects of norepinephrine (NE) or 1,1-dimethyl-4-phenylpiperinium (DMPP) or electrical stimulation of the sympathetic ganglia of pithed rats.
(2) Relatively weaker GUS activity was also detected in pith parenchyma.
(3) Both d- and l-amphetamine were also compared for their pressor and tachycardic activity in pithed rats.
(4) Intravenous administration of T-2 to pithed rats did not alter blood pressure or heart rate at a time when, in conscious rats, both blood pressure and heart rate were increased.
(5) Monoiodo-Ang II was found to be a potent, full agonist in in vivo bioassays and a more potent (2.5-fold) pressor agent than the native hormone Ang II in the pithed rat.
(6) APP 201-533 [3-amino-6-methyl-5-phenyl-2(1H)-pyridinone] was investigated in vivo in anesthetized and unanesthetized dogs and pithed open-chest cats and in vitro in guinea pig atria and papillary muscles, skinned muscle fibers from pig hearts, and rat myocardium.
(7) The effects of quinpirole, a specific dopamine DA2 receptor agonist, on autonomic nervous control of heart rate, were studied in normotensive pithed rats, by analysing its action on the tachycardia and bradycardia evoked by electrical stimulation of the cardioaccelerator (10 V; 1 ms; 0.5, 1, 3, 6 Hz) and vagus (10 V; 1 ms; 3, 6, 9 Hz) nerves respectively.
(8) Pith cells can shift from the C- to the C+ state by a process known as habituation.
(9) The pressor actions of ET3 and arginine vasopressin (AVP) were compared with one another in pithed rats in the presence of the calcium channel activator BAY K 8644 or the calcium channel antagonist nifedipine i.a.
(10) Both human endothelin 1 (ET1) and rat endothelin 3 (ET3) produced dose-dependent pressor effects in the pithed rat.
(11) Viprostol did not antagonize the tachycardia induced by stimulation of the discrete segments at C7-T1 (cardio-accelerator) of the spinal cord in pithed SHR, suggesting that viprostol did not activate the presynaptic alpha-adrenoceptors.
(12) In pithed rats, the vasopressor response to dihydroergotoxine was reduced competitively by yohimbine, and non-competitively by nifedipine, but not by prazosin or methysergide, showing that the vasoconstriction is mediated by alpha 2-adrenoceptors.
(13) The antagonistic effects of a new inositol phosphate derivative, D-myoinositol-1,2,6-trisphosphate (PP56), on pressor responses to preganglionic sympathetic nerve stimulation and exogenously administered phenylephrine or neuropeptide Y (NPY) were investigated in vivo in the pithed rat.
(14) We conclude that in contrast to the increase in diastolic pressure elicited by B-HT 920, calcium channels are not involved in the cirazoline-induced pressor responses in the pithed cat.
(15) Acute or chronic adrenalectomy did not alter the pressor responses and chronotropic effect of angiotensin in the pithed rat.
(16) Habituated cells derived from inducible pith cells give rise to normal plants whose leaf and pith tissues require cytokinin for growth in culture.
(17) The endovenous perfusion of the splenic material in acidified and alkalinized forms caused significant increases of the mean blood pressure in normal, vagotomized and pithed rats, showing that, in contradiction to previous reports, changes in pH did not affect its hypertensive activity.
(18) The dose-response curves of three alpha-agonists noradrenaline, St 587 and B-HT 933 in pithed rats were shifted rightwards by pretreatment (i.v.
(19) In pithed rats, only pindolol produced a definite fall of blood pressure.
(20) The bradycardia was reduced but not blocked by pre-treatment with guanethidine, yohimbine, propranolol or pithing.
Substance
Definition:
(n.) That which underlies all outward manifestations; substratum; the permanent subject or cause of phenomena, whether material or spiritual; that in which properties inhere; that which is real, in distinction from that which is apparent; the abiding part of any existence, in distinction from any accident; that which constitutes anything what it is; real or existing essence.
(n.) The most important element in any existence; the characteristic and essential components of anything; the main part; essential import; purport.
(n.) Body; matter; material of which a thing is made; hence, substantiality; solidity; firmness; as, the substance of which a garment is made; some textile fabrics have little substance.
(n.) Material possessions; estate; property; resources.
(n.) Same as Hypostasis, 2.
(v. t.) To furnish or endow with substance; to supply property to; to make rich.
Example Sentences:
(1) No differences between the two substances were observed with respect to side effects and general tolerability.
(2) Modulation of the voltage-gated K+ conductance in T-lymphocytes by substance P was examined.
(3) During the digestion of these radiolabeled bacteria, murine bone marrow macrophages produced low-molecular-weight substances that coeluted chromatographically with the radioactive cell wall marker.
(4) Intracellular localization of the labeled substance in the tumor tissue was examined autohistoradiographically.
(5) Substances with a leaving group at the C-3 position form unsaturated conjugated cyclic adducts and are mutagenic only in the His D3052 frameshift strains with an intact excision repair system (no urvA mutation).
(6) A substance with a chromatographic mobility of Rf = 0.8 on TLC plates having an intact phosphorylcholine head group was also formed but has not yet been identified.
(7) Serum pepsinogen 1, serum gastrin, ABO blood groups, secretor status of ABH blood group substances and behavioral factors were studied in 15 patients with duodenal ulcer and 61 their relatives affected and unaffected to duodenal ulcer.
(8) Agarose-albumin beads may be useful for removing protein-bound substances from the blood of patients with liver failure, intoxication with protein-bound drugs, or specific metabolic deficits.
(9) Urine tests in six patients with other kidney diseases and with uraemia and in seven healthy persons did not show this substance.
(10) Substance P, a potent vasodilating peptide, seems to be released from trigeminal nerve endings in response to nervous stimulation and is involved in the transmission of painful stimuli within the periphery.
(11) Regulators concerned about physician behavior and confronted by demands of nonphysicians to prescribe controlled substances may find EDT a good solution.
(12) These results are discussed in the light of the mode of action of the substances used.
(13) Most cis AB sera have anti-B activity, essentially at 4 degrees C. In saliva A and H substances are found in normal amounts but B substance is only evidenced by inhibition of autologous cells agglutination.
(14) We have investigated some of the factors which affect the retention times of these substances in reversed-phase HPLC on columns of 5-micron octadecylsilyl silica.
(15) The data indicate that adult neurons with an intrinsic ability to regenerate axons can respond to substances with neurotrophic or neurite-promoting activities in tissue cultures.
(16) The authors describe the role played by these substances in the pathogenesis of inflammations, their importance in the regulation of intraocular pressure and in the development of cystoid macular oedema.
(17) They were more irregularly curved and consisted of various substances.
(18) We examined 10 life areas clustered around the general categories of "substance use," "social functioning," and "emotional and interpersonal functioning."
(19) In certain cases, the effects of these substances are enhanced, in others, they are inhibited by compounds that were isolated from natural sources or prepared by chemical synthesis.
(20) The following possible explanations were discussed: a) the tested psychotropic drugs block prostaglandin receptors in the stomach; b) the test substances react with prostaglandin in the nutritive solution; c) the substances stimulate metabolic processes in the stomach wall that break down prostaglandin.