[Role of PAF for the formation of gastric mucosal injury induced by ischemia-reinfusion in the rat].
Oxyradicals of neutrophils are supposed to play a role in the formation of gastric mucosal injury induced by ischemia-reinfusion (I-R). Recently, platelet-activating factor (PAF) is suggested to be involved in the I-R injury as one of chemical mediators since this substance may be produced in hypoxic tissue, stimulating oxyradical generation of neutrophils. In the present study, using CV-3988, a PAF antagonist, the severity of gastric mucosal damage and chemiluminescence (CL) activity of neutrophils of circulating blood were measured to evaluate the role of PAF in the I-R injury. SD rats fasted overnight were anesthetized and instilled 0.1N HCl into the stomach. Rats were then subjected to reduction of blood pressure to 20-30 mmHg for 20 min by bleeding followed by reinfusion of shed blood for 20 min. Two groups of rats each received 10 mg/kg CV-3988 (PAF-A grup) or saline (I-R group) i.v. 5 min prior to bleeding. After killing rats, the area of gross gastric lesions and the index of histologic damage were assessed. In separate PAF-A and I-R groups of rats, and control rats received saline i.v. and no hypotension, blood samples were collected from the portal vein and the abdominal aorta 45 min after acid instillation. Luminol-dependent CL stimulated by PMA of blood samples was measured using the photometer Monolight 401. CL activity was expressed as [peak CL/neutrophils number].(ABSTRACT TRUNCATED AT 250 WORDS)
Iwai
A
A
First Department of Internal Medicine, Nagoya City University Medical School.
Itoh
M
M
Yokoyama
Y
Y
Yasue
N
N
Imai
S
S
Matsusako
K
K
Kawai
T
T
Matsuba
S
S
Katoh
N
N
Okayama
N
N
D000818:Animals; D005609:Free Radicals; D005753:Gastric Mucosa / Q000098:blood supply* / Q000473:pathology; D008297:Male; D009504:Neutrophils / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010972:Platelet Activating Factor / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D015427:Reperfusion Injury / Q000378:metabolism* / Q000473:pathology
D005609:Free Radicals; D010972:Platelet Activating Factor; D010100:Oxygen