Effect of graded doses of methysergide on basal and pentagastrin stimulated gastric secretion in anaesthetised rats.
The effect of continuous infusion (iv) of graded doses of methysergide (0.1-50 microgram(s)/kg/hr) was studied on basal and pentagastrin (5 microgram(s)/kg/hr) stimulated gastric acid secretion in anaesthetised rats by the slow, continuous stomach perfusion method. Both basal and pentagastrin stimulated acid secretion indicated a biphasic response. Methysergide induced stimulation at a lower dose of 1 microgram(s)/kg/hr and inhibition at higher doses of 20-50 microgram(s)/kg/hr. The stimulatory effect may be due to postsynaptic receptor blockade while the inhibitory effect at higher dose may be due to blockade of presynaptic 5-HT autoreceptors, or due to a direct inhibitory effect of unknown basis.
Goel
R K
RK
Department of Pharmacology, Banaras Hindu University, Varanasi, India.
Maiti
R N
RN
Bhattacharya
S K
SK
D000777:Anesthetics; D000818:Animals; D001481:Basal Metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008784:Methysergide / Q000494:pharmacology*; D010418:Pentagastrin / Q000494:pharmacology*; D051381:Rats; D012702:Serotonin Antagonists / Q000494:pharmacology*
D000777:Anesthetics; D012702:Serotonin Antagonists; D010418:Pentagastrin; D008784:Methysergide