Vascular desensitisation--possible role of prostaglandins.
Prolonged exposure to noradrenaline (NA) brings about an increase in the release of prostaglandin (PG)-like material from rat aortic strip. The release is greater with oxymetazoline while methoxamine decreases it. These effects are blocked by yohimbine and prazosin respectively. Pretreatment with 6-OHDA or reserpine diminishes the release of PG-like material. Barium chloride, a non-specific spasmogen, does not affect the release significantly. It appears therefore that the source of PG-like material is presynaptic and that its release mechanism is linked to an alpha 2 (alpha 2) adrenoceptor. It is proposed that this release of PG-like material contributes to the development of desensitisation in vascular tissue.
Pereira
J S
JS
Department of Pharmacology, Goa Medical College, Bambolim.
Dhume
V G
VG
D'Souza
R S
RS
Abhraham
G J
GJ
D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000502:physiology; D004351:Drug Resistance; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D008729:Methoxamine / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology*; D010109:Oxymetazoline / Q000494:pharmacology; D011453:Prostaglandins / Q000096:biosynthesis / Q000378:metabolism*; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology
D011453:Prostaglandins; D011942:Receptors, Adrenergic, alpha; D010109:Oxymetazoline; D008729:Methoxamine; D009638:Norepinephrine