Endothelin-1 in human intestine resected for necrotizing enterocolitis.
OBJECTIVE
We asked if the tissue concentration of the potent vasoconstrictor endothelin-1 (ET-1) is greater in areas of human preterm intestine that demonstrate histologic evidence of necrotizing enterocolitis (NEC) when compared with relatively healthy areas within the same resection specimen. We then evaluated if ET-1 participates in hemodynamic regulation within intestinal subserosal arterioles harvested from portions of human preterm intestine that demonstrate NEC.


METHODS
Human preterm intestine resected for NEC was divided into three zones based on proximity to the perforation (zone 1 most proximal, zone 3 most distal). Histologic evidence of NEC was determined in each zone (normal = 0, advanced necrosis = 6). The tissue concentration of ET-1 was determined by enzyme-linked immunosorbent assay within intestinal homogenates prepared from each zone. Arteriolar hemodynamics were determined in vitro on subserosal arterioles harvested from different zones. Arteriolar flow rate, diameter, and resistance were determined at pressure gradients (DeltaP) of 20 and 40 mmHg under control conditions and again after blockade of endothelin ET A receptors with BQ610 (10 -9 mol/L).


RESULTS
The tissue concentration of ET-1 (pg/mg protein) and histologic score in the three zones were: zone 1: 84 +/- 14, 5.5 +/- 0.3; zone 2: 99 +/- 12, 4.7 +/- 0.4, and zone 3: 33 +/- 9, 0.8 +/- 0.6, respectively (M +/- SD, n = 10 resection specimens, P < .05, zone 3 vs zones 1 and 2). Zone 2 arterioles demonstrated significantly lower flow rate and diameter and increased resistance under control conditions than zone 3 arterioles when DeltaP was either 20 or 40 mmHg (n = 7, P < .05). Treatment with BQ610 had no effect on zone 3 arterioles but significantly vasodilated zone 2 arterioles, increasing flow rate and vessel diameter, and decreasing vascular resistance (n = 7, P < .05).


CONCLUSIONS
The tissue concentration of ET-1 is greater in human preterm intestine that demonstrates histologic evidence of NEC. Arterioles harvested from intestine exhibiting histologic evidence of NEC demonstrate vasoconstriction when compared with arterioles from relatively healthy intestine in the same resection specimen. This vasoconstriction was reversed by blockade of endothelin ET A receptors.
Center for Cell and Vascular Biology, Columbus Children's Research Institute, Department of Pediatrics, Division of Neonatology, Ohio State University, USA. nowickip@pediatrics.ohio-state.edu
Philip T
PT
Nowicki
David J
DJ
Dunaway
Craig A
CA
Nankervis
Peter J
PJ
Giannone
Peter J
PJ
Giannnone
Kristina M
KM
Reber
Susan B
SB
Hammond
Gail E
GE
Besner
Donna A
DA
Caniano
D001160:Arterioles / Q000378:metabolism*; D001783:Blood Flow Velocity; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1 / Q000378:metabolism*; D020345:Enterocolitis, Necrotizing / Q000378:metabolism* / Q000503:physiopathology / Q000601:surgery; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D066298:In Vitro Techniques; D007223:Infant; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000098:blood supply / Q000601:surgery; D009842:Oligopeptides / Q000494:pharmacology; D014661:Vasoconstriction; D014665:Vasodilator Agents / Q000494:pharmacology
D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1; D009842:Oligopeptides; D014665:Vasodilator Agents; C087220:BQ 610