Efferent branchial artery reactivity in the Blacktip reef shark, Carckarhinus melanopterus (Carcharhinidae: Elasmobranchii)

Efferent branchial arterial ring preparations from the Blacktip reef shark, Carcharhinus melanopterus, were used to investigate the tissue reactivity to a range of pharmacological agents. The arterial responses elicited by adrenaline and noradrenaline were somewhat variable. Isoprenaline, a β-adreno...

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Bibliographic Details
Published inComparative biochemistry and physiology. C, Comparative pharmacology and toxicology Vol. 114; no. 2; pp. 165 - 170
Main Author Bennett, M.B.
Format Journal Article
LanguageEnglish
Published Elsevier Inc 01.06.1996
Subjects
Adenosine
adrenergic
artery
Carcharhinus
cholinergic
elasmobranch
histamine
purinergic
Adenosine
histamine
purinergic
cholinergic
adrenergic
Carcharhinus
artery
elasmobranch
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Summary:Efferent branchial arterial ring preparations from the Blacktip reef shark, Carcharhinus melanopterus, were used to investigate the tissue reactivity to a range of pharmacological agents. The arterial responses elicited by adrenaline and noradrenaline were somewhat variable. Isoprenaline, a β-adrenoceptor agonist, always produced a vasodilatation and phenylephrine, an α-adrenoceptor agonist, always produced a vasoconstrictory response. The cholinergic agonists, acetylcholine, methylcholine and carbamylcholine, all constricted these branchial arteries. Atropine could successfully antagonise the effects of acetylcholine; suggesting that muscarinic receptors were being activated. Histamine produced modest increases in tension. Adenosine ADP and ATP all produced bimodel tissue responses, with initial contractions reversing to relaxations at higher concentrations. The arterial responses could not be adequately explained with reference to the accepted mammalian purinoceptor scheme.
ISSN:0742-8413
DOI:10.1016/0742-8413(96)00023-0