Abstract
To evaluate the effects of midazolam on the angiokinesis of segments of rabbits’ thoracic aorta stripped of endothelium and stimulated by adrenaline.
Two groups of aortic rings removed from albinic rabbits anesthetized with thiopental were used (Group I - 6 animals; Group II - 12 animals), stripped of endothelium, studied in an organ chamber, perfused by Krebs-Henseleit solution. The groups were stimulated by adrenaline, recording the maximum contraction and dT/dt at 12″, 36″, 60″ and 120″. When the plateau phase was reached, the vessel was washed with perfusion solution, recording relaxation at 2´, 4´ and 6´. When the base values were reached, Group I underwent a new adrenergic stimulus; and Group II was stimulated with midazolam and then with adrenaline, and the same values were recorded. T test was applied as a statistical analysis when two variables were studied. When studying more than two variables the Anova test was used, supplemented by the Tuckey test.
Group I did not show any significant difference between the two stimuli. Group II - the midazolam significantly reduced the maximum contraction induced by adrenaline (83.01 ±4.11%) (p < 0.01). The Dt/dt was reduced at (57.06±8.47%), and also at 36″(70.59±5.26%). There was no signigicance at 60″ and 120″(P<0.01).
The relaxation increased significantly at all measurements-at 2´-adrenaline/midozolam:44.06±9.62%(p<). At 4´-adrenaline:53.08±8.3%; adrenaline/midazolam: 61.68±8.50%(p<0.01), At 6´-adrenaline: 76.26±5.45%; adrenaline/midazolam: 84.20±7.96%(p<0.01) (Mol Cell Biochem 246: 13-17,2003)
Midazolam signigicantly reduced the maximum contraction obtained by the adrenergic stimulus as well as the Dt/dt in the initial phases of contraction. The relaxation speed also increased.
Article FootNote
Fundacâ Cardiovascular Sâo Francisco de EMESCAN, Santa Monica Assis/ServCor Belo Horizonte,Brasil
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Reference
Fragen RJ, Gahl F, Caldwell N: A water soluble benzodiazepine, RO21398, for induction of anesthesia. Anesthesiology 49: 41–43,1978
Shafer A: Complications of sedation with midazolam in the Intensive Care Unit: A comparison with other sedative regimens. Crit Care Med 26: 947–956,1998
Al-Khudairi D, Whitwam JG, McCloy W: Midazolam and diazepam for gastrocopy. Anaesthesia 37: 1001–1006,1982
Anley DF Pozo M: Treatment of status epilepticus with midazolam in the critic care setting. Int J Clin Pract 1: 34–35,2000
Aun C. Flynn PJ, Richar DSJ, Major E: A comparison of midazolam and diazepam for intravenous sedation in dentistry. Anaesthesia 39: 589–591 1984
Baber R, Hobest A, Munro I, Purcell G, Binstead R: Midazolam as an intravenous induction agent for general anahestesy: A clinical trial. Anaesth Intens Care 10: 29–35,1982
Blumer JL: Clinical pharmacology of midazolam in infants and children. Clin Pharmacol 35: 37–47,1998
Bergreen L, Erikson I, Mollhenolt P, Sunzel M: Changes in respiratory pattern after repeated doses of diazepam and midazolam in healthy subjects. Acta Anaesthiol Scand 3: 667–678,1987
Knudsen L, Cold GE, Holgard HO, Johansen UT, Jensen S: The effects of midazolam on cerebral blood flow and oxygen consumption. Anaesthesia 45: 1016–1019,1990
Marty J, Nitemberg A, Blanchet F, Zouioueche S, Desmonts JM: Effects of midazolam on the coronary circulation in patients with coronary artery disease. Anaesthesiology 14: 206–300,1986
Rao RB, Ely SF, Hoffman RS: Deaths related to liposuction. New Engl J Med 13: 1471–1475,1999
Vanhoute PM, Rubany GM, Miller VM, Houston DS: Modulation of vascular smooth muscle contraction by the endothelium. Ann Rev Physiol 48: 307–320,1986
Furchgott RF: Role of endothelium in responses of vascular smooth muscles. Ann Rev Pharmacol Toxicol 24: 175–179,1984
Angus JA, Cocks TM, Sato K: The alpha adrenoreceptors on endothelial cells. Fed Proc 45: 2355–2359,1986
Nilsson H: Interactions between membrane potential and intracellular calcium concentration in vascular smooth muscle. Acta Physiol Scand 1664: 559–566,198?
Walsh MP: Regulation of vascular smooth muscle tone. Can J Physiol Pharmacol 72: 919–935,1994
Jaggar JH, Wellman GC, Heppner TJ et al.: Calcium channel, ryanodine receptors and calcium activated potassium channels: A functional unit for regulating arterial tone. Acta Physiol Scand 164: 577–585, 1998
Karaki H, Osaki H, Hold M, Saito MM, Amano KI, Myamoto S, Nakazawa H, Won KJ, Sato K: Calcium movements, distribution and function in smooth muscle. Pharmacol Rev 49: 157–230,1997
Shiraishi Y, Kanmura Y, Yamagushi S, Yoshimura N, Hob T: Possible mechanisms underlying the midazolam induced relaxation of the nor adrenaline contraction in rabbit mesenteric resistance artery. Br J Pharmacol 121: 1155–1163,1997
Yamaguchi S, Kanmura Y, Yoshimura N: Effects of midazolam in smooth muscle of the rabbit mesenteric artery. Anesth Anal 84: 199–205, 1997
Cheng EY, Mazzeo AJ, Bosnjak ZJ, Coon RL, Kampine JP: Direct relaxant effects of intravenous anesthesics on airway smooth muscles. Anesth Anal 83: 162–168,1996
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2003 Springer Science+Business Media Dordrecht
About this chapter
Cite this chapter
Borges, A.A.F.R., Gomes, O.M. (2003). Effects of midazolam on the contraction and relaxation of segments of thoracic aorta stripped of endothelium and stimulated by adrenaline — Experimental study in rabbits. In: Zahradka, P., Wigle, J., Pierce, G.N. (eds) Vascular Biochemistry. Molecular and Cellular Biochemistry: An International Journal for Chemical Biology in Health and Disease, vol 41. Springer, Boston, MA. https://doi.org/10.1007/978-1-4615-0298-2_2
Download citation
DOI: https://doi.org/10.1007/978-1-4615-0298-2_2
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-5010-1
Online ISBN: 978-1-4615-0298-2
eBook Packages: Springer Book Archive