Analgesic and Thermic Effects, and Cerebrospinal Fluid and Plasma Pharmacokinetics, of Intracerebroventricularly Administered Morphine in Normal and Sensitized Rats

Author:

Bhargava Hemendra N1,Villar Vincent M12,Cortijo Julio12,Morcillo Esteban J12

Affiliation:

1. Department of Pharmaceutics and Pharmacodynamics, College of Pharmacy, The University of Illinois at Chicago, Chicago, Illinois, USA

2. Department of Pharmacology, Faculty of Medicine and Odontology, University of Valencia, Valencia, Spain

Abstract

Abstract The relationship between asthma and opioids has barely been investigated. This study examines whether active sensitization of rats changes the analgesic and thermic effects of intracerebroventricular morphine or the pharmacokinetics of the drug. Morphine (5, 10 and 20 μg) was given intracerebroventricularly to sensitized (active immunization to ovalbumin and Al(OH)3 then airway challenge with ovalbumin after 12 days) and normal (i.e. non-sensitized) male Sprague-Dawley rats. The tail-flick latencies and changes in colon temperature were determined before morphine injection and at 30 min intervals for a period of 300 min afterwards. Results were expressed as the area under the time-response curve. The analgesic and hyperthermic response to morphine for sensitized rats was less than that obtained for normal rats. Cerebrospinal fluid and blood samples were collected periodically for a period of 240 min and morphine levels were determined by a highly sensitive radioimmunoassay. The pharmacokinetic parameters half-life, terminal elimination rate constant and the mean residence time were determined in both cerebrospinal fluid and plasma by non-compartmental analysis. The area under the cerebrospinal fluid concentration-time curve from time zero to infinity was higher for sensitized rats than for normal rats for all three doses of morphine but these differences did not correspond with similar changes in pharmacological responses. In conclusion, the attenuated analgesic and thermic responses to intracerebroventricular morphine in the sensitized rats might be a result of pharmacodynamic alterations rather than to pharmacokinetic changes.

Funder

National Institute of Drug Abuse

CICYT (Comision Interministerial Investigación Científica y Técnica, Madrid, Spain).

Publisher

Oxford University Press (OUP)

Subject

Pharmaceutical Science,Pharmacology

Reference21 articles.

1. Analgesic and hyperthermic effects of intravenously administered morphine in the rat are related to its serum levels;Bhargava;J. Pharmacol. Exp. Ther.,1991

2. Binding of [3H][D-Ala2, MePhe4, Gly5-ol]enkephalin, [3H][D-Pen2, D-Pen5]enkephalin, and [3H]U-69,593 to airway and pulmonary tissues of normal and sensitized rats;Bhargava;Peptides,1997

3. IgE antibody-mediated inflammation of rat lung: histologic and bronchoalveolar lavage assessment;Blythe;Am. Rev. Respir. Dis.,1986

4. The role of endogenous opioids and their receptors in the immune system;Carr;Proc. Soc. Exp. Biol. Med.,1991

5. Enkephalins and endorphins;Copolov;Clinical pharmacological and therapeutic implications. Drugs,1983

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3