| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Pediatrics, College of Medicine and Public Health, The Ohio State University and Children's Research Institute, Columbus, Ohio 43205
Newborn
intestine is uniquely prone to vasoconstriction in response to a wide
variety of perturbations. To test the hypothesis that endothelin (ET)-1
is an important factor in this process, we determined the effects of
exogenous ET-1 administration and blockade of endogenous ET-1 in vivo
and in vitro in 3- and 35-day-old swine. Intramesenteric artery
administration of exogenous ET-1 to vascularly isolated in vivo gut
loops (10
9 M/kg bolus) caused vasoconstriction and
reduced gut O2 uptake similarly in these age groups.
Selective blockade of ETA or ETB receptors with
BQ-610 or BQ-788, respectively, in vascularly isolated in vivo gut
loops had no effect on gut vascular resistance or O2 uptake
in either age group; within in vitro gut loops, BQ-610 significantly
increased vasoconstriction when perfusion pressure was reduced below
baseline, but only in 3-day-old animals; i.e., it impaired the
autoregulatory response to perfusion pressure reduction. Exogenous ET-1
significantly decreased capillary perfusion within in vitro gut loops,
as evidenced by a decrease in capillary filtration coefficient, but
only in 3-day-old animals; furthermore, blockade of endogenous ET-1
activity with BQ-610 significantly enhanced capillary filtration
coefficient in 3-day-old animals and increased O2
extraction ratio. ET-1 did not depress intestinal metabolic rate, as
evidenced by its effect on the O2 uptake-blood flow
relationship; it did compromise tissue oxygenation because of its
effects on intestinal O2 transport. ET-1 concentration in
mesenteric venous effluent exceeded arterial concentration, but only in
3-day-old intestine, suggesting production of ET-1 by newborn
intestine. We conclude that ET-1 exerts an age-dependent effect on
intestinal hemodynamics in postnatal intestine, having a greater impact
in 3- than in 35-day-old intestine.
swine; newborn intestine; intestinal circulation physiology
This article has been cited by other articles:
|
|
 |
|
  P. T. Nowicki IL-1beta alters hemodynamics in newborn intestine: role of endothelin Am J Physiol Gastrointest Liver Physiol, September 1, 2006; 291(3): G404 - G413. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. M. Reber, B. Y. Su, K. R. Clark, D. L. Pohlman, C. E. Miller, and P. T. Nowicki Developmental expression of eNOS in postnatal swine mesenteric artery Am J Physiol Gastrointest Liver Physiol, December 1, 2002; 283(6): G1328 - G1335. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. A. Nankervis, D. J. Dunaway, and C. E. Miller Endothelin ETA and ETB receptors in postnatal intestine Am J Physiol Gastrointest Liver Physiol, April 1, 2001; 280(4): G555 - G562. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. A. Nankervis, D. J. Dunaway, and P. T. Nowicki Determinants of terminal mesenteric artery resistance during the first postnatal month Am J Physiol Gastrointest Liver Physiol, April 1, 2001; 280(4): G678 - G686. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. A. Nankervis, G. M. Schauer, and C. E. Miller Endothelin-mediated vasoconstriction in postischemic newborn intestine Am J Physiol Gastrointest Liver Physiol, October 1, 2000; 279(4): G683 - G691. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
