TY - JOUR
T1 - 5-Hydroxytryptamine1-like receptors linked to increases in intracellular calcium concentration and inhibition of cyclic AMP accumulation in cultured vascular smooth muscle cells derived from bovine basilar artery
AU - Ebersole, B. J.
AU - Diglio, C. A.
AU - Kaufman, D. W.
AU - Berg, K. A.
PY - 1993
Y1 - 1993
N2 - Vascular smooth muscle cells derived from bovine basilar artery by the explant method were grown in culture. In the presence of 1 μM forskolin and the phosphodiesterase inhibitor rolipram, 5-hydroxytryptamine (5-HT) agonists inhibited by 90 to 100% the accumulation of intracellular cyclic AMP (cAMP) with a rank order of potency 5-carboxamidotryptamine (5-CT) ≥ 5-HT > 5- benzyloxytryptamine = sumatriptan > RU24969 [5-methoxy-3(1,2,3,6-tetrahydro- 4-pyridinyl)-1H indole succinate] > (±)-8-hydroxydipropylaminotetralin. In suspensions of cells loaded with the calcium-sensitive probe fura-2, 5-CT and 5-HT caused a biphasic increase in the concentration of intracellular free calcium ([Ca++](i)) that consisted of both transient and sustained phases. The transient phase was reduced and the sustained phase abolished in the absence of extracellular calcium. The EC50 for 5-CT-induced increase in [Ca++](i) (6 nM) was similar to that for inhibition of cAMP accumulation (1.3 nM). Both the inhibition of cAMP accumulation and increase in [Ca++](i) were inhibited by the antagonist methiothepin (pA2 = 8.9), but not by the antagonists ketanserin, spiperone and pindolol. Both the inhibition of cAMP accumulation and increase in [Ca++](i) were attenuated by greater than 85% in cells that were pretreated with pertussis toxin. PI turnover was not stimulated by 5-CT. The rank order of agonist potency, as well as the antagonist sensitivity, indicates responses mediated by one or more 5-HT1-like-type receptors. Bovine basilar artery cells that naturally express 5-HT1-like receptors may serve as a useful model for the study of 5- HT1-like receptor-mediated signal transduction mechanisms in vascular smooth muscle.
AB - Vascular smooth muscle cells derived from bovine basilar artery by the explant method were grown in culture. In the presence of 1 μM forskolin and the phosphodiesterase inhibitor rolipram, 5-hydroxytryptamine (5-HT) agonists inhibited by 90 to 100% the accumulation of intracellular cyclic AMP (cAMP) with a rank order of potency 5-carboxamidotryptamine (5-CT) ≥ 5-HT > 5- benzyloxytryptamine = sumatriptan > RU24969 [5-methoxy-3(1,2,3,6-tetrahydro- 4-pyridinyl)-1H indole succinate] > (±)-8-hydroxydipropylaminotetralin. In suspensions of cells loaded with the calcium-sensitive probe fura-2, 5-CT and 5-HT caused a biphasic increase in the concentration of intracellular free calcium ([Ca++](i)) that consisted of both transient and sustained phases. The transient phase was reduced and the sustained phase abolished in the absence of extracellular calcium. The EC50 for 5-CT-induced increase in [Ca++](i) (6 nM) was similar to that for inhibition of cAMP accumulation (1.3 nM). Both the inhibition of cAMP accumulation and increase in [Ca++](i) were inhibited by the antagonist methiothepin (pA2 = 8.9), but not by the antagonists ketanserin, spiperone and pindolol. Both the inhibition of cAMP accumulation and increase in [Ca++](i) were attenuated by greater than 85% in cells that were pretreated with pertussis toxin. PI turnover was not stimulated by 5-CT. The rank order of agonist potency, as well as the antagonist sensitivity, indicates responses mediated by one or more 5-HT1-like-type receptors. Bovine basilar artery cells that naturally express 5-HT1-like receptors may serve as a useful model for the study of 5- HT1-like receptor-mediated signal transduction mechanisms in vascular smooth muscle.
UR - http://www.scopus.com/inward/record.url?scp=0027340583&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027340583&partnerID=8YFLogxK
M3 - Article
C2 - 8394913
AN - SCOPUS:0027340583
SN - 0022-3565
VL - 266
SP - 692
EP - 699
JO - Journal of Pharmacology and Experimental Therapeutics
JF - Journal of Pharmacology and Experimental Therapeutics
IS - 2
ER -