NEUROPEPTIDE-Y POTENTIATES CONTRACTILE RESPONSE TO NOREPINEPHRINE IN SKATE CORONARY-ARTERY

Citation
C. Bjenning et al., NEUROPEPTIDE-Y POTENTIATES CONTRACTILE RESPONSE TO NOREPINEPHRINE IN SKATE CORONARY-ARTERY, The American journal of physiology, 265(2), 1993, pp. 80000661-80000665
Citations number
31
Categorie Soggetti
Physiology
ISSN journal
00029513
Volume
265
Issue
2
Year of publication
1993
Part
2
Pages
80000661 - 80000665
Database
ISI
SICI code
0002-9513(1993)265:2<80000661:NPCRTN>2.0.ZU;2-7
Abstract
The skate is an extant representative of the first vertebrate group wi th a coronary circulation, the elasmobranch fish. Histochemical studie s have revealed that skate coronary arteries are innervated by adrener gic nerves as well as by nerves showing neuropeptide Y (NPY)-like immu noreactivity. This study investigates the effect of NPY in the coronar y system of an elasmobranch fish, a vertebrate that first evolved 450 million years before mammals and the mammalian coronary circulation. T he responses of vascular ring preparations of the coronary artery from the longnose skate (Raja rhina) were measured using isometric force t ransducers. The main effect of NPY was a potentiation of the amplitude of the norepinephrine-induced contraction, leaving the pD2 value (-lo g 50% effective concentration) for norepinephrine unaffected. NPY per se occasionally contracted the coronary rings in higher concentrations . The potentiation response may not involve the endothelium and was ab olished by pretreatment with tetrodotoxin. We conclude from this study that NPY potentiates norepinephrine-induced contraction in skate coro nary artery via an indirect pathway.