Role of the Peripheral Sympathetic Innervations in Controlling Cerebral Blood Flow after the Transection of Bilateral Superior Cervical Sympathetic Ganglia Two Weeks

Background: Cerebral blood vessels are mainly supplied by sympathetic nerves arising from the superior cervical ganglia and cerebral blood volume may be influenced by bilateral superior cervical ganglionectomy (SCG). Various stages of cerebral blood volume changes depended on the time following bilateral excision of SCG. In this study, we emphasize the subacute effect (two weeks) on the local cerebral blood flow (LCBF). Material and Methods: Sprague-Dawley rats weighing 250- 400 gm (n = 20) were selected into two groups. Under the ambient temperature 20˚C, the first group animals (n = 10) received sham operation and the other group animals (n = 10) underwent bilateral SCG. The LCBF and O2 delivery of 14 brain structures were measured for each animal by the use of 14C-iodoantipyrine technique two weeks after the operation. Results: The average of LCBF was decreased from 150 ml/100 gm/min to 129 ml/100 gm/min after bilateral SCG. Only the LCBF at basal ganglia was increased from 108 ml/min/100 g in the sham-operated group to 118 ml/min/100g in the SCG group. A mean of 14 % reduction of LCBF was estimated. In 14 brain structures, the delivery amount of O2 was all decreased, except in basal ganglia. However, these changes of LCBF and the delivery amount of O2 at these 14 brain structures did not reach the significant differences. Conclusions: The present results show that chronic effect (two weeks) of bilateral SCG on LCBF was not only in a de