Destructive effect of digitalis overdose on blood-brain barrier in rats; an experimental study

Cardiac glycosides are widely used in critical cardiac diseases despite their unexplained mechanisms on cardio-respiratory system and other autonomic complications within both intra-uterine and post-natal life. The aim of this study is to investigate if digitalis overdose could cause a result in such complications by a destructive effect on blood-brain barrier (BBB).

Twenty-five male Sprague Dawley rats weighing 300–350 g were divided into the following groups: control (n=5), sham (isotonic) (n=5), therapeutic dose (n=5), arrhythmogenic dose (n=5), and lethal dose (n=5). The animals were euthanized and their brains were extracted. The brains were histopathologically and immunohistochemically examined to evaluate BBB morphology in the superior temporal cortex.

One animal died because of experimental procedures on the first day. Macroscopic examination of brains revealed brain edema, subarachnoid hemorrhage (SAH), and narrowed cisterns in toxic doses of digitalis-treated animals. Brain histopathological examination of these groups revealed bloody subarachnoid and cisternal spaces, cortical arteriolar vasospasm, neurodegeneration, and even peri-arteriolar neuroglial component fragmentation; these changes induced BBB destruction in the high-dose digitalis-treated animals.

Digitalis should not be used with overdoses if the cardio-respiratory arrhythmia is unexpectedly appearing in low doses against the possibility of defected or disrupted BBB.