0000000000462514
AUTHOR
M. Angeles Martinez-cuesta
Involvement of neuronal processes and nitric oxide in the inhibition by endotoxin of pentagastrin-stimulated sastric acid secretion
Administration of E. coli endotoxin (1 mg kg-1, i.v.) abolished the acid response induced by the i.v. infusion of pentagastrin (8 micrograms kg-1 h-1) in the continuously perfused stomach of the anaesthetized rat. Local serosal application of tetrodotoxin (36 ng per rat) completely restored acid responses to pentagastrin in endotoxin-treated rats. However, pretreatment with atropine (0.5 mg kg-1, s.c.), capsaicin (20, 30, and 50 mg kg-1, s.c. 2 weeks before the study) or guanethidine (16 mg kg-1, s.c. 3 and 16h before) did not influence the inhibitory effects of endotoxin. Continuous i.v. infusion with NG-nitro arginine methyl ester (L-NAME, 10 mg kg-1 h-1) restored the secretory responses …
A cerebral nitrergic pathway modulates endotoxin-induced changes in gastric motility
1 This study analyses the neural pathway involved in the modulation of gastric motor function by stress. 2 Systemic administration of low doses of endotoxin (40 m gk g 71 , i.v.) prevents the increase in gastric tone induced by 2-deoxy-D-glucose (200 mg kg 71 , i.v., 2-DG) in urethane-anaesthetized rats. 3 Functional inhibition of aAerent neurones by systemic administration of capsaicin (20+30+50 mg kg 71 , i.m.) in adult rats prevented the inhibitory eAects of endotoxin. 4 Pre-treatment with the nitric oxide synthase (NOS) inhibitor, N G -nitro-L-arginine methyl ester (LNAME), both i.v. (10 mg kg 71 ) and i.c. (200 mg rat 71 ), prevented the inhibitory eAects of endotoxin on gastric tone i…
Role of the Endothelium in the Relaxation Induced by Propofol and Thiopental in Isolated Arteries from Man
Abstract Induction of anaesthesia with intravenous propofol and thiopental is often accompanied by hypotension. This study evaluates whether propofol and thiopental induce relaxation of isolated arteries from man and whether this effect is modulated by the endothelium. Mesenteric artery rings (with and without endothelium) from 12 patients were placed in organ baths and precontracted with phenylephrine before addition of propofol (10−3 M) or thiopental (10−3 M). Relaxation induced by propofol and thiopental was evaluated for rings with intact endothelium in the presence of the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME; 10−4 M) or the cyclooxygenase inhibitor i…
Anatomical differences in responsiveness to vasoconstrictors in the mesenteric veins from normal and portal hypertensive rats
The present study evaluates the effects of pre-hepatic portal hypertension, induced in rats by partial portal vein ligation, on the responsiveness of rostral (proximal) and caudal (distal) rings from the mesenteric vein. The anatomical origin of the sample influenced the response to vasoconstrictors in sham-operated animals, and this pattern of reactivity was specifically modified in portal-ligated rats. In veins from sham-operated rats, contraction induced by a submaximal concentration of KCl (60 mM) was greater in proximal than in distal rings. Vasopressin and 5-hydroxytryptamine contracted mainly distal rings, methoxamine showed a greater effect on proximal rings, and endothelin-1 and an…