title: Cerebral microcirculatory responses of insulin-resistant rats are preserved to physiological and pharmacological stimuli.
abstract: OBJECTIVE
  Previously, we have shown that IR impairs the vascular reactivity of the major cerebral arteries of ZO rats prior to the occurrence of Type-II diabetes mellitus. However, the functional state of the microcirculation in the cerebral cortex is still being explored.
  
  
  METHODS
  We tested the local CoBF responses of 11-13-week-old ZO (n = 31) and control ZL (n = 32) rats to several stimuli measured by LDF using a closed cranial window setup.
  
  
  RESULTS
  The topical application of 1-100 μm bradykinin elicited the same degree of CoBF elevation in both ZL and ZO groups. There was no significant difference in the incidence, latency, and amplitude of the NMDA-induced CSD-related hyperemia between the ZO and ZL groups. Hypercapnic CoBF response to 5% carbon-dioxide ventilation did not significantly change in the ZO compared with the ZL. Topical bicuculline-induced cortical seizure was accompanied by the same increase of CoBF in both the ZO and ZL at all bicuculline doses.
  
  
  CONCLUSIONS
  CoBF responses of the microcirculation are preserved in the early period of the metabolic syndrome, which creates an opportunity for intervention to prevent and restore the function of the major cerebral vascular beds.
authors: Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA. instiadam@gmail.com
authors: Adam
authors: A
authors: Institoris
authors: Laura
authors: L
authors: Lenti
authors: Ferenc
authors: F
authors: Domoki
authors: Edina
authors: E
authors: Wappler
authors: Tamás
authors: T
authors: Gáspár
authors: Prasad V
authors: PV
authors: Katakam
authors: Ferenc
authors: F
authors: Bari
authors: David W
authors: DW
authors: Busija
mesh_terms: D000818:Animals; D001640:Bicuculline / Q000009:adverse effects / Q000494:pharmacology*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D003292:Convulsants / Q000009:adverse effects / Q000494:pharmacology*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000503:physiopathology*; D006935:Hypercapnia / Q000378:metabolism / Q000503:physiopathology; D007333:Insulin Resistance; D008297:Male; D008833:Microcirculation / Q000187:drug effects*; D051381:Rats; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology
chemical_list: D003292:Convulsants; D001640:Bicuculline