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Analysis of the responses of rainbow lizard (Agama agama Linn.). Isolated portal vein to electrical stimulation and to drugs.
Methods Find Exp Clin Pharmacol. 1983 Dec; 5(10):673-84.MF

Abstract

The responses of the rainbow lizard (Agama agama Linn.) isolated portal vein to transmural electrical stimulation and to drugs have been examined. The isolated venous muscle preparation strongly contracted in response to exogenously administered adrenaline and noradrenaline (10(-8)-2.5 x 10(-6) M) and also weakly contracted to acetylcholine and 5-hydroxytryptamine (10(-7) - 10(-5) M). The vein relaxed in response to exogenous administrations of isoprenaline (10(-8) - 2.5 x 10(-6) M) and adenosine triphosphate (ATP, 10(-7) - 10(-5) M). Transmural electrical stimulation of the isolated vein at 1-40 Hz induced frequency-dependent contractions of the venous smooth muscle which were inhibited or abolished by tetrodotoxin, alpha-adrenoceptor blockers, adrenergic neurone blocking agents, local anaesthetics, and by pretreatment of rainbow lizards with reserpine. Analysis of these findings shows that the electrical stimulation-evoked contractions of the venous blood vessel resulted from the excitation of post-ganglionic sympathetic neurones. A comparison of the relative potentiation of the venous preparation contractions induced by electrical stimulation, adrenaline and noradrenaline suggested that noradrenaline is the sympathetic transmitter mediating the contractile effects due to electrical excitation. The advantages of this preparation for studying sympathetic nerve-smooth muscle mechanisms and as a pharmacological model for investigating venous blood vessel activity are discussed.

Authors

No affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

6142991

Citation

Ojewole, J A.. "Analysis of the Responses of Rainbow Lizard (Agama Agama Linn.). Isolated Portal Vein to Electrical Stimulation and to Drugs." Methods and Findings in Experimental and Clinical Pharmacology, vol. 5, no. 10, 1983, pp. 673-84.
Ojewole JA. Analysis of the responses of rainbow lizard (Agama agama Linn.). Isolated portal vein to electrical stimulation and to drugs. Methods Find Exp Clin Pharmacol. 1983;5(10):673-84.
Ojewole, J. A. (1983). Analysis of the responses of rainbow lizard (Agama agama Linn.). Isolated portal vein to electrical stimulation and to drugs. Methods and Findings in Experimental and Clinical Pharmacology, 5(10), 673-84.
Ojewole JA. Analysis of the Responses of Rainbow Lizard (Agama Agama Linn.). Isolated Portal Vein to Electrical Stimulation and to Drugs. Methods Find Exp Clin Pharmacol. 1983;5(10):673-84. PubMed PMID: 6142991.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Analysis of the responses of rainbow lizard (Agama agama Linn.). Isolated portal vein to electrical stimulation and to drugs. A1 - Ojewole,J A, PY - 1983/12/1/pubmed PY - 1983/12/1/medline PY - 1983/12/1/entrez SP - 673 EP - 84 JF - Methods and findings in experimental and clinical pharmacology JO - Methods Find Exp Clin Pharmacol VL - 5 IS - 10 N2 - The responses of the rainbow lizard (Agama agama Linn.) isolated portal vein to transmural electrical stimulation and to drugs have been examined. The isolated venous muscle preparation strongly contracted in response to exogenously administered adrenaline and noradrenaline (10(-8)-2.5 x 10(-6) M) and also weakly contracted to acetylcholine and 5-hydroxytryptamine (10(-7) - 10(-5) M). The vein relaxed in response to exogenous administrations of isoprenaline (10(-8) - 2.5 x 10(-6) M) and adenosine triphosphate (ATP, 10(-7) - 10(-5) M). Transmural electrical stimulation of the isolated vein at 1-40 Hz induced frequency-dependent contractions of the venous smooth muscle which were inhibited or abolished by tetrodotoxin, alpha-adrenoceptor blockers, adrenergic neurone blocking agents, local anaesthetics, and by pretreatment of rainbow lizards with reserpine. Analysis of these findings shows that the electrical stimulation-evoked contractions of the venous blood vessel resulted from the excitation of post-ganglionic sympathetic neurones. A comparison of the relative potentiation of the venous preparation contractions induced by electrical stimulation, adrenaline and noradrenaline suggested that noradrenaline is the sympathetic transmitter mediating the contractile effects due to electrical excitation. The advantages of this preparation for studying sympathetic nerve-smooth muscle mechanisms and as a pharmacological model for investigating venous blood vessel activity are discussed. SN - 0379-0355 UR - https://www.unboundmedicine.com/medline/citation/6142991/Analysis_of_the_responses_of_rainbow_lizard__Agama_agama_Linn____Isolated_portal_vein_to_electrical_stimulation_and_to_drugs_ DB - PRIME DP - Unbound Medicine ER -