PMID: 6108518Oct 1, 1980Paper

Effects of some alpha-adrenoceptor agonists and antagonists on the guinea-pig ileum

Naunyn-Schmiedeberg's Archives of Pharmacology
M AndréjakH Schmitt

Abstract

The purpose of the present study was to further characterize the alpha-adrenoceptors located on parasympathetic fibres. Segments of guinea-pig ileum were stimulated by transmural electrical pulses, and the ensuing contractions, which are due to the release of acetylcholine from postganglionic parasympathetic fibres, were monitored. Clonidine and tramazoline, which are thought to act preferentially on presynaptic alpha-adrenoceptors, reduced the contractions, whereas phenylephrine and methoxamine, postsynaptic alpha-adrenoceptor agonists, were ineffective. Contractions induced by acetylcholine were not changed by clonidine but were abolished by atropine. Yohimbine, piperoxan, phentolamine and the thymoxamine reversed or prevented the inhibitory effect of clonidine. Prazosin and AR-C239 did not antagonize this effect. The inhibitory effect of tramazoline was antagonized by piperoxan but not AR-C239 or by prazosin. Naloxone did not alter the action of clonidine, and piperoxan did not change the inhibitory effect of morphine. In conclusion, these experiments suggest the presence on cholinergic postganglionic fibres of both opiate receptors and alpha-adrenoceptors.. The latter appear to resemble more closely alpha 2-adrenoceptors th...Continue Reading

References

Nov 3, 1975·Naunyn-Schmiedeberg's Archives of Pharmacology·K StarkeH D Taube
Jan 1, 1977·Reviews of Physiology, Biochemistry and Pharmacology·K Starke
Sep 1, 1977·Naunyn-Schmiedeberg's Archives of Pharmacology·H D TaubeE Borowski
Nov 1, 1979·Naunyn-Schmiedeberg's Archives of Pharmacology·H Kilbinger, I Wessler
Apr 29, 1978·Lancet·M S GoldH D Kleber
Jan 1, 1972·Naunyn-Schmiedeberg's Archives of Pharmacology·K Starke
Jul 1, 1974·Biochemical Pharmacology·S Z Langer
Jun 1, 1968·British Journal of Pharmacology and Chemotherapy·H W Kosterlitz, A J Watt
Jun 1, 1963·British Journal of Pharmacology and Chemotherapy·B G BENFEY, S A GRILLO

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Citations

Sep 1, 1986·Naunyn-Schmiedeberg's Archives of Pharmacology·R E Loiacono, D F Story
Apr 1, 1983·Naunyn-Schmiedeberg's Archives of Pharmacology·R A LefebvreM G Bogaert
Dec 1, 1985·Naunyn-Schmiedeberg's Archives of Pharmacology·K J Broadley, P F Grassby
Mar 1, 1982·Naunyn-Schmiedeberg's Archives of Pharmacology·Y PommierH Schmitt
May 1, 1984·Naunyn-Schmiedeberg's Archives of Pharmacology·R A LefebvreM G Bogaert
Mar 25, 2011·Attention Deficit and Hyperactivity Disorders·Barbara Langen, Rita Dost
Sep 10, 1982·European Journal of Pharmacology·W H Hsu
Aug 21, 1990·European Journal of Pharmacology·R A LefebvreF A De Beurme
Jan 1, 1986·Comparative Biochemistry and Physiology. C, Comparative Pharmacology and Toxicology·T KitazawaH Kondo
Jan 1, 1986·Comparative Biochemistry and Physiology. C, Comparative Pharmacology and Toxicology·T KitazawaH Kondo
Apr 1, 1994·Journal of Veterinary Pharmacology and Therapeutics·S MaugeriG Soldani
Mar 1, 1996·British Journal of Pharmacology·L Liu, I M Coupar
Oct 1, 1990·The Journal of Pharmacy and Pharmacology·C BlandizziM del Tacca
Sep 19, 2001·American Journal of Veterinary Research·G ReC Girardi
May 1, 1985·Naunyn-Schmiedeberg's Archives of Pharmacology·M MarcoliG M Frigo
Sep 1, 1984·Naunyn-Schmiedeberg's Archives of Pharmacology·G SoldaniM Impicciatore
Sep 1, 1985·Clinical and Experimental Pharmacology & Physiology·A M HuchetH Schmitt
Nov 1, 1980·Naunyn-Schmiedeberg's Archives of Pharmacology·A T Sullivan, G M Drew
Oct 1, 1981·British Journal of Pharmacology·K Morita, R A North
Jan 1, 1994·Pharmacology & Therapeutics·R R Ruffolo, J P Hieble

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