(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.
With
Definition:
(n.) See Withe.
(prep.) With denotes or expresses some situation or relation of nearness, proximity, association, connection, or the like.
(prep.) To denote a close or direct relation of opposition or hostility; -- equivalent to against.
(prep.) To denote association in respect of situation or environment; hence, among; in the company of.
(prep.) To denote a connection of friendship, support, alliance, assistance, countenance, etc.; hence, on the side of.
(prep.) To denote the accomplishment of cause, means, instrument, etc; -- sometimes equivalent to by.
(prep.) To denote association in thought, as for comparison or contrast.
(prep.) To denote simultaneous happening, or immediate succession or consequence.
(prep.) To denote having as a possession or an appendage; as, the firmament with its stars; a bride with a large fortune.