Calcitriol protects the Blood-Brain Barrier integrity against ischemic stroke and reduces vasogenic brain edema via antioxidant and antiapoptotic actions in rats

Brain Res Bull. 2019 Aug:150:281-289. doi: 10.1016/j.brainresbull.2019.06.010. Epub 2019 Jun 18.

Abstract

Background: Vasogenic brain edema is the most important complication of ischemic stroke that aggravates primary brain injury. Ischemia-Reperfusion (IR)-induced Blood-Brain Barrier (BBB) impairment limits the use of recombinant tissue plasminogen activator (r-tPA) by increasing the possibility of hemorrhagic transformation and contributing to vasogenic edema and neuroinflammation. This study examined the effects of post-ischemic treatment with calcitriol on cerebral infarction, vasogenic edema formation and BBB disruption in a rat model of ischemic stroke.

Methods: Male Sprague-Dawley rats were divided into three main groups, including the sham, IR + vehicle and IR + calcitriol groups. Transient focal cerebral ischemia was induced by a 60-min-long occlusion of the left middle cerebral artery. The infarct volume, brain edema, BBB permeability and antioxidant enzyme activities were evaluated 24 h after ischemia. Immunohistochemical analysis was conducted to investigate cell apoptosis and Brain-Derived Neurotrophic Factor (BDNF) protein expression five days after ischemia.

Results: Compared to the IR + vehicle group, the IR + calcitriol group showed a reduced brain infarction volume, attenuated brain edema formation and improved BBB function. These protective effects were followed by the upregulation of antioxidant enzyme activities in the brain tissue. Additionally, a diminished cell apoptosis and an increased BDNF immunoreactivity were obtained in the IR + calcitriol group.

Conclusion: Calcitriol may reduce brain injury and attenuate vasogenic edema by upregulating antioxidant enzymes activities, reducing cell apoptosis and increasing BDNF protein in the brain tissue in a rat model of ischemic stroke.

Keywords: Antioxidant enzymes; Apoptosis; BDNF; Brain edema; Calcitriol; Stroke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / pharmacology
  • Apoptosis / drug effects
  • Blood-Brain Barrier / drug effects*
  • Brain / metabolism
  • Brain Edema / drug therapy*
  • Brain Ischemia / metabolism
  • Calcitriol / metabolism
  • Calcitriol / pharmacology*
  • Disease Models, Animal
  • Infarction, Middle Cerebral Artery / complications
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Stroke / metabolism
  • Tissue Plasminogen Activator / pharmacology

Substances

  • Antioxidants
  • Tissue Plasminogen Activator
  • Calcitriol