Rat-tails

Ratten-gift, n. rat poison, specif, white arsenic, -pulver, n. rat powder, rat poison, -schwanz, m. rat-tail file, -tod, m. rat poison, -ver-tilgungsmittel, n. rat killer, vermicide. Ratter, m. grating, grate, screen, riddle, rauben, v.t. rob. 

Since 1973, several authors have proved that there is a relationship between thermostability of collagen and the extent of hydroxylation of the proline residues31,34). Equilibrium measurements of the peptides al-CB 2 of rat tail and rat skin revealed a higher rm, for al-CB 2 (rat skin)157). The sequence of both peptides is identical except that in the peptide obtained from rat skin, the hydroxylation of the proline residues in position 3 has occurred to a higher extent than in the case of al-CB 2 (rat tail). Thus, a mere difference of 1.8 hydroxy residues per chain causes a ATm of 26 K. Obviously, there are different stabilizing interactions in the triple-helical state, that means al-CB 2 (rat skin) forms more exothermic bonds than al-CB 2 (rat tail) in the coil triple-helix transition. This leads to an additional gain of enthalpy which overcompensates the meanwhile occurring losses of entropy. 

Achike FI, Kwan CY (2002) Characterization of a novel tetrandrine-induced contraction in rat tail artery. Acta Pharmacol Sin 23(8) 698-704... 

In toxicity studies, acute toxicity tests are usually carried out in the rat, mouse, cat, and dog. Subacute toxicity studies for IM products are performed by giving SC injections to rats and IM injections to dogs. In IV studies the rat tail vein or a front leg is used. Deliberate overdosing usually washes out metabolism differences between species. In dogs it is common to give an IV dose five times that intended for humans. In rats this is increased to 10 times. 

Figure 17 Appearance kinetics of sucrose across untreated Transwell filters (0.4 Um pore size) and those coated with a cross-linked rat tail collagen matrix. In both cases the systems were stirred at 100 rpm.

Fig. 1. (A) CD spectra of rat-tail collagen in native state, heat-denatured state, and in...

Iatridis JC et al (1999) Compression-induced changes in intervertebral disc properties in a rat tail model. Spine (Phila Pa 1976) 24(10) 996-1002... 

We carefully dissected rat tail arteries and loaded them with a Ca2+ indicator, Fluo-3. After a rectangular glass capillary was inserted into the lumen of the excised arteries, [Ca2+] in smooth muscle cells within the arterial wall was visualized using a confocal microscope. Brief electrical shocks were delivered at 5 Hz to the preparations to stimulate the sympathetic nerve network present in the adventitia. We found Ca2+ signals with diverse spatiotemporal patterns, Ca2+ waves and oscillations in individual smooth muscle cells during the sympathetic nerve stimulation (lino et al 1994). 

For further purification, primary cultures of PBEC are passaged at the third day of culture by gentle trypsinization at room temperature. This enzymatic treatment selectively releases endothelial cells, leaving behind contaminating cells, such as pericytes and smooth muscle cells. Usually, contamination by nonendothelial cells should be below 1-3%. Endothelial cells are then seeded at a density of 30,000-50,000 cells/cm2 on rat-tail collagen-coated cell culture inserts (Figure 17.5). 

Martin WJ, Tsou K, Walker JM. (1998). Cannabinoid receptor-mediated inhibition of the rat tail-flick reflex after microinjection into the rostral ventromedial medulla. Neurosci Lett. 242(1) 33-36. Mascolo N, Jain R, Jain SC, Capasso F. (1989). Ethnopharmacologic investigation of ginger (Zingiber officinale). J Ethnopharmacol. Nov. 27(1-2) 129-40. 

This derivative is one of the most potent morphine-antagonists yet examined (19 X nalorphine in rats [221]) and it gives no analgesic response in the mouse hot-plate and rat tail-flick tests [222]. It is inactive, furthermore, in the mouse... 

Some 1,4-benzodiazepine derivatives, loosely regarded as cyclic versions of basic anilide analgesics, antagonize pethidine in the rat tail-flick test [246]. Activity orders are about 200 times below that of nalorphine for some 4-allyl... 

Freund, L, Deutsch, M., and Sprecher, A. 1986. Connective-tissue polarity Optical second-harmonic microscopy, crossed-beam summation, and small-angle scattering in rat-tail tendon. Biophys. J. 50 693-712. 

However, methane-diphosphonate could not prevent the growth of apatite crystals in vitro on prepared sinews of rats tail out of a metastable solution with calcium and phosphate ions. On the contrary, the precipitated crystalline particles were bigger and better crystallized than those from control solutions. This is in surprising contrast to most of the information from the literature. No other calcium phosphate minerals besides apatite have been found by X-ray diffraction, whereas under comparable conditions brushite and octacalcium phosphate grow on collagenous sinews549. ... 

These peptides were characterized in vitro and found to be powerful opioid agonists in the mouse vas deferens (MVD) and guinea pig ileum (GPI) assay. In vivo (rat tail-flick) they are only active when administered directly to the brain - a general limitation of simple linear peptides consisting of natural L-amino acids - but with less potency and shorter duration of action than morphine (Casy and Parfitt, 1986). 

Rao, T. S., Correa, L. D., Reid, R. T., Lloyd, G. K. Evaluation of anti-nociceptive effects of neuronal nicotinic acetylcholine receptor (nAChR) ligands in the rat tail-flick assay, Neuropharmacology 1996, 35, 393-405. 

Sullivan, J. P., Briggs, C. A., Donnelly-Roberts, D., Brioni, J. D., Radek, R. J., McKenna, D. G., Campbell, J. E., Arneric, S. P., Decker, M. W. (+)-Epibatidine can differentially evoke responses mediated by putative subtypes of nicotinic acetylcholine receptors (nAChR) ligands in the rat tail-flick assay, Med. Chem. Res. 1994, 4, 502-516. 

Saponara S, Sgaragli G, Fusi F. 2002. Quercetin as a novel activator of L-type Ca2 + channels in rat tail artery smooth muscle cells. Br J Pharmacol 135 1819-1827. 

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