Effects of intestinal ischemia on in vitro activity of adjacent jejunum in samples obtained from ponies.
OBJECTIVE
To determine whether intestinal ischemia would alter activity of the jejunum in vitro or alter staining characteristics for certain types of enteric neurotransmitters.


METHODS
Jejunal samples obtained from 10 ponies.


METHODS
Jejunal samples were obtained from locations proximal and distal to an area of small intestine made ischemic for 60 minutes. A portion of each sample was stained to detect substance P-like immunoreactivity, cholinergic and adrenergic neurons, and nitric oxide synthase. Portions of the remaining samples were suspended in muscle baths. General activity patterns (frequency and amplitude of contraction), responses to neuronal depolarization induced by electrical field stimulation (EFS), and responses to 1 microM norepinephrine (NE) were compared with responses of a normal section of small intestine obtained prior to ischemic insult.


RESULTS
Staining patterns were not altered. Proximal and distal sections had evidence of decreased contractility, compared with the normal section. Contraction frequency also was decreased, and distal sections had lower contraction frequency than proximal sections. Relaxation responses were decreased in distal sections. Responses to NE differed significantly for distal and proximal sections, compared with normal sections.


CONCLUSIONS
Short-term ischemia can significantly affect adjacent bowel. Contractile and relaxation responses are impaired. Discrepancies in intestinal motility patterns and alterations in response to NE for sections proximal and distal to ischemic intestine could lead to clinical ileus or slowed transit of ingesta.
Malone
E D
ED
Department of Clinical and Population Sciences, College of Veterinary Medicine, University of Minnesota, St Paul 55108, USA.
Kannan
M S
MS
D000818:Animals; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D004558:Electric Stimulation; D006734:Horse Diseases / Q000503:physiopathology*; D006736:Horses; D007150:Immunohistochemistry / Q000662:veterinary; D066298:In Vitro Techniques; D007511:Ischemia / Q000503:physiopathology / Q000662:veterinary*; D007583:Jejunum / Q000098:blood supply*; D009119:Muscle Contraction / Q000502:physiology; D009130:Muscle, Smooth / Q000098:blood supply* / Q000187:drug effects; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009638:Norepinephrine / Q000097:blood / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D013373:Substance P / Q000032:analysis / Q000096:biosynthesis
D013373:Substance P; D011189:Potassium Chloride; D019001:Nitric Oxide Synthase; D004299:Dopamine beta-Hydroxylase; D002795:Choline O-Acetyltransferase; D009638:Norepinephrine