Article |

Investigations on the Filter Capacity of the Dog's Brain:  A Contribution to the Question of Cerebral Arteriovenous Shunts

Pius Prosenz, MD
Arch Neurol. 1972;26(6):479-488. doi:10.1001/archneur.1972.00490120019001.
Text Size: A A A
Published online

In 28 dogs with controlled ventilation and circulation, the passage of microspheres (MS) injected into the carotid in size ranges from 1μ to 100μ through the brain was observed. A cannula placed into a cortical vein provided recovery of MS from pure cortical venous blood and a semicontinuous outflow measurement. In control animals MS up to 7μ passed freely through the brain; bigger MS were almost completely entrapped. In states of ischemic and hypoxemic hypoxia, as well as in prolonged reactive hyperperfusion caused by a previous hypoxic exposure, MS up to 76μ passed through the brain within two minutes after injection. Hypercapnia did not change the filter capacity. The presence in the dog's brain of arteriovenous connections much larger than capillaries, but not larger than 76μ, is postulated. These connections, closed in the normal brain, are opened by hypoxia.


Sign In to Access Full Content

Don't have Access?

Register and get free email Table of Contents alerts, saved searches, PowerPoint downloads, CME quizzes, and more

Subscribe for full-text access to content from 1998 forward and a host of useful features

Activate your current subscription (AMA members and current subscribers)

Purchase Online Access to this article for 24 hours





Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).
Submit a Comment


Some tools below are only available to our subscribers or users with an online account.

Sign In to Access Full Content

Related Content

Customize your page view by dragging & repositioning the boxes below.