Local cerebral blood flow response to locally infused 2-chloroadenosine during hypotension in piglets.
Brain Res Dev Brain Res
; 61(1): 73-7, 1991 Jul 16.
Article
en En
| MEDLINE
| ID: mdl-1914158
ABSTRACT
Brain interstitial adenosine increases during hypotension in piglets. If adenosine is to participate in the regulation of neonatal cerebral blood flow (CBF) during hypotension, it must retain its vasodilatory action under that condition. To examine this issue, we studied the effects of locally infused 2-chloroadenosine (2-CADO), a stable adenosine analog, on local CBF in the piglet frontal cortex during normotension and graded hemorrhagic hypotension. We used the modified brain microdialysis/hydrogen clearance technique to simultaneously infuse 2-CADO into the frontal cortex and measure local CBF from the same area. When 2-CADO from 10(-8) M to 10(-3) M was infused under control conditions (n = 7), CBF increased 61% at 10(-5) M, 167% at 10(-4) M, and 210% at 10(-3) M. In hypotension experiments, local infusion of 10(-5) M 2-CADO (n = 8) caused significant increases in CBF (P less than 0.05) under control conditions (MABP = 65 mmHg) and at hypotensive blood pressures of 55 mmHg and 44 mmHg, respectively. At a blood pressure of 33 mmHg, however, infusion of the analog failed to increase CBF. Local infusion of 10(-3) M 2-CADO also produced a similar change in CBF during graded hypotension. These results indicate that 2-CADO dilates intracerebral vessels during normotension, and mild and moderate hypotension, and support the hypothesis that endogenous adenosine mediates autoregulatory adjustments of CBF during hypotension in newborn piglets.
Buscar en Google
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
2-Cloroadenosina
/
Corteza Cerebral
/
Circulación Cerebrovascular
/
Hipotensión
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
Idioma:
En
Revista:
Brain Res Dev Brain Res
Asunto de la revista:
CEREBRO
/
NEUROLOGIA
Año:
1991
Tipo del documento:
Article