Alpha1- and alpha2-adrenoceptors at different levels of the canine saphenous vein

  • S. Guimarães
  • D. Moura
  • J. P. Nunes
  • M. J. Vaz-da-Silva
  • J. T. Guimarães
Conference paper
Part of the Journal of Neural Transmission book series (NEURAL SUPPL, volume 34)


Presynaptic alpha2- and postsynaptic alpha1-adrenoceptors were compared at the distal and proximal parts of the dog saphenous vein. The results obtained show that: (1) yohimbine is more effective against postsyaptic responses to phenylephrine distally than proximally. On the contrary, WB- 4101 is more effective proximally; (2) phenylephrine increases inositol monophosphate production at both levels, but the increase is more pronounced distally; (3) UK-14,304 and adrenaline reduce and yohimbine and phentolamine increase the release of 3H-noradrenaline caused by electrical stimulation at both levels. However, while adrenaline as well as the antagonists are equipotent at the two levels, UK-14,304 is more potent distally than proximally.

In conclusion, we suggest that: more alpha1A-adrenoceptors exist distally than proximally; imidazoline sites can exist at the distal level which contribute to the higher potency of UK-14,304 distally.


Saphenous Vein Inositol Phosphate Distal Level Proximal Level Human Saphenous Vein 
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  1. Bevan JA, Bevan RD, Laher I (1985) Role of alpha-adrenoceptors in vascular control. Clin Sci 68 [Suppl 10]: 83s–89sPubMedGoogle Scholar
  2. Berridge MJ, Dawson RMC, Downes CP, Heslop, JP, Irvine RF (1983) Changes in the levels of inositol phosphates after agonist-dependent hydrolysis of membrane phosphoinositides. Biochem J 212: 473–482PubMedGoogle Scholar
  3. Constantine JW, Lebel W, Archer R (1982) Functional postsynaptic α2- but not ar adrenoceptors in dog saphenous vein exposed to phenoxybenzamine. Eur J Pharmacol 85: 325–329PubMedCrossRefGoogle Scholar
  4. De Mey JC, Vanhoutte PM (1981) Uneven distribution of postjunctional alphar and alpha2-like adrenoceptors in canine arterial and venous smooth muscle. Circ Res 48: 875–884PubMedGoogle Scholar
  5. Docherty JR, Hyland L (1985) Evidence for neuro-effector transmission through postjunctional α2-adrenoceptors in human saphenous vein. Br J Pharmacol 84: 573–576PubMedGoogle Scholar
  6. Docherty JR, MacDonald A, McGrath JC (1979) Further subclassification of α-adrenoceptors in the cardiovascular system, vas deferens and anococcygeus of the rat. Br J Pharmacol 67: 421P–422 PPubMedGoogle Scholar
  7. Drew GM, Whiting SB (1979) Evidence for two distinct types of postsynaptic α-adrenoceptors in vascular smooth muscle in vivo. Br J Pharmacol 67: 207–215PubMedGoogle Scholar
  8. Flavahan NA, Rimele JP, Cooke JP, Vanhoutte PM (1984) Characterization of postjunctional alphar and alpha2-adrenoceptors activated by exogenous or nerve released norepinephrine in the canine saphenous vein. J Pharmacol Exp Ther 230: 399–705Google Scholar
  9. Flavahan NA, Cooke JP, Shepherd JT, Vanhoutte PM (1987) Human postjunctional alphar and alpha2-adrenoceptors: differential distribution in arteries of the limbs. J Pharmacol Exp Ther 241: 361–365PubMedGoogle Scholar
  10. Gonçalves J, Carvalho F, Guimaraes S (1989) Uptake inhibitors do not change the effect of imidazoline α2-adrenoceptor agonists on transmitter release evoked by single pulse stimulation in mouse vas deferens. Naunyn-Schmiedebergs Arch Pharmacol 339: 288–292PubMedGoogle Scholar
  11. Guimarães S, Osswald W (1969) Adrenergic receptors in the veins of the dog. Eur J Pharmacol 5: 133–140PubMedCrossRefGoogle Scholar
  12. Guimarães S, Nunes JP (1990) The effectiveness of α2-adrenoceptor activation increases from the distal to the proximal part of the veins of canine limbs. Br J Pharmacol 101: 387–393PubMedGoogle Scholar
  13. Guimarães S, Brandao F, Paiva MQ (1978) A study of the adrenoceptor-mediated feedback by using adrenaline as a false transmitter. Naunyn-Schmiedebergs Arch Pharmacol 305: 185–188PubMedCrossRefGoogle Scholar
  14. Guimarães S, Paiva MQ, Polonia J J (1983) Alphar and alpha2-adrenoceptors of the dog saphenous vein and their relation to the sympathetic nerve terminals. Prog Neuropsychopharmacol (Abstr) [Suppl]: 155Google Scholar
  15. Guimarães S, Paiva MQ, Moura D (1987) Alpha2-adrenoceptor-mediated responses to so-called selective alpharadrenoceptor agonists after partial blockade of alphar adrenoceptors. Naunyn-Schmiedebergs Arch Pharmacol 335: 397–402PubMedCrossRefGoogle Scholar
  16. Han L, Abel PW. Minneman KP (1987) Alpharadrenoceptor subtypes linked to different mechanisms for increasing intracellular Ca2+ in smooth muscle. Nature 329: 333–335Google Scholar
  17. Hicks PE, Barras M, Herman G, Mauduit P, Armstrong JM, Rossignol B (1991) α-Adrenoceptor subtypes in dog saphenous vein that mediate contraction and inositol phosphate production. Br J Pharmacol 102: 151–161Google Scholar
  18. Langer SZ, Shepperson NB (1982) Recent developments in vascular smooth muscle pharmacology: the post-synaptic α2-adrenoceptor. Trends Pharmacol Sci 3: 440–444CrossRefGoogle Scholar
  19. McGrath JC, Brown CM, Wilson VG (1989) Alpha-adrenoceptors: a critical review. Med Res Rev 9: 407–533PubMedCrossRefGoogle Scholar
  20. Michel MC, Hanft G, Gross G (1990) Alpha1B-but not alpha1A-adrenoceptors mediate inositol phosphate generation. Naunyn-Schmiedebergs Arch Pharmacol 341: 385–387PubMedGoogle Scholar
  21. Minneman LP, Han C, Abel PW (1988) Comparison of alpharadrenoceptor subtypes distinguished by chloroethylclonidine and WB4101. Mol Pharmacol 33: 509–514PubMedGoogle Scholar
  22. Pereira O, Moura D, Nunes P, Vaz-da-Silva MJ, Guimaraes S (1991) Involvement of α1 and α2-adrenoceptors in the responses of proximal and distal segments of the canine saphenous vein to exogenous and endogenous noradrenaline. Naunyn- Schmiedebergs Arch Pharmacol 343: 616–622PubMedGoogle Scholar
  23. Polónia JJ, Paiva MQ, Guimaraes S (1985) Pharmacological characterization of postsynaptic α-adrenoceptor subtypes in five different dog arteries in vitro. J Pharm Pharmacol 37: 205–208PubMedCrossRefGoogle Scholar
  24. Ruffolo RR, Jr. Waddel JE, Yaden EC (1982) Heterogeneity of postsynaptic alpha adrenergic receptors in mammalian aorta. J Pharmacol Exp Ther 221: 309–314Google Scholar
  25. Shepperson NB, Langer SZ (1981) The effects of the 2-aminotetrahydronaphtalene derivative M7 a selective α2-adrenoceptor agonist in vitro. Naunyn-Schmiedebergs Arch Pharmacol 318: 10–13PubMedCrossRefGoogle Scholar
  26. Shoji T, Tsuru H, Shigei T (1983) A regional difference in the distribution of postsynaptic alpha-adrenoceptor subtypes in canine veins. Naunyn-Schmiedebergs Arch Pharmacol 324: 246–255PubMedCrossRefGoogle Scholar
  27. Starke K (1972) Alpha sympathomimetic inhibition of adrenergic and cholinergic transmission in the rabbit heart. Naunyn-Schmiedebergs Arch Pharmacol 274: 18–45PubMedCrossRefGoogle Scholar
  28. Thom S, Calvete J, Hayes R, Martin G, Sever P (1985) Human vascular smooth muscle responses mediated by alpha2 mechanisms in vivo and in vitro. Clin Sci 68: 147s–150sPubMedGoogle Scholar
  29. Wilffert B, Timmermans PBMWM, Van Zwieten PA (1982) Extrasynaptic location of alpha-2 and noninnervated beta-2 adrenoceptors in the vascular system of the pithed normotensive rat. J Pharmacol Exp Ther 221: 762–768PubMedGoogle Scholar
  30. Yamaguchi I, Kopin IJ (1988) Differential inhibition of alpha-1 and alpha-2 adrenoceptor-mediated pressor responses in pithed rats. J Pharmacol Exp Ther 214: 275–287Google Scholar

Copyright information

© Springer-Verlag 1991

Authors and Affiliations

  • S. Guimarães
    • 1
  • D. Moura
    • 1
  • J. P. Nunes
    • 1
  • M. J. Vaz-da-Silva
    • 1
  • J. T. Guimarães
    • 2
  1. 1.Department of PharmacologyFaculty of MedicinePortoPortugal
  2. 2.Department of BiochemistryFaculty of MedicinePortoPortugal

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