Nguyen H Oanh X, Goracke-Postle Cory J, Kaminski Lori L, Overland Aaron C, Morgan Andrew D, Fairbanks Carolyn A
Department of Pharmaceutics, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Ann N Y Acad Sci. 2003 Dec;1009:82-105. doi: 10.1196/annals.1304.009.
Agmatine has been previously proposed to represent a novel neurotransmitter. One of the criteria required to test that hypothesis is that the exogenously administered chemical produces pharmacological effects similar to the physiological effects of the putative neurotransmitter. Since agmatine was first identified in brain, approximately sixty studies of the in vivo effects of exogenously administered agmatine have been reported. Despite the assertion that agmatine functions as a neuromodulator/neurotransmitter, the vast majority of experiments have administered agmatine through systemic (rather than central) routes of administration. Systemic delivery of agmatine for studies of centrally mediated phenomenon (e.g., pain, spinal cord injury, cardiovascular responses) relies on the presumption that agmatine (a polar compound) gains appreciable access to the CNS. The mechanism by which agmatine crosses the blood-brain barrier is not well understood. A number of studies have examined the in vivo effects of agmatine following central administration (e.g., intracerebroventricular and intrathecal). This paper summarizes and provides a comparison between the systemic versus central routes of administration for delivery of agmatine in experimental subjects.
胍丁胺先前被认为是一种新型神经递质。检验该假设所需的标准之一是，外源性给予的化学物质产生的药理作用与假定神经递质的生理作用相似。自从胍丁胺首次在大脑中被发现以来，已经报道了大约60项关于外源性给予胍丁胺的体内效应的研究。尽管有人断言胍丁胺具有神经调节剂/神经递质的功能，但绝大多数实验都是通过全身（而非中枢）给药途径给予胍丁胺的。通过全身给药来研究中枢介导的现象（如疼痛、脊髓损伤、心血管反应），其依据是假定胍丁胺（一种极性化合物）能够大量进入中枢神经系统。胍丁胺穿过血脑屏障的机制尚不清楚。一些研究已经考察了中枢给药（如脑室内和鞘内给药）后胍丁胺的体内效应。本文总结并比较了在实验对象中通过全身给药与中枢给药途径给予胍丁胺的情况。
