+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Contractile responses of longitudinal muscle strip to 5-HT and influences of divalent cations in the guinea-pig isolated colon

Contractile responses of longitudinal muscle strip to 5-HT and influences of divalent cations in the guinea-pig isolated colon

Journal of Smooth Muscle Research 30(2): 65-72

The contractile effects of 5-hydroxytryptamine (5-HT) and influences of several kinds of divalent cations were investigated on longitudinal muscle strips of the guinea-pig isolated distal colon. 5-HT (10 nM-10 microM) produced phasic contractions which were partially inhibited by atropine (1 microM) and markedly inhibited by tetrodotoxin (1 microM), indicating that 5-HT acts mainly on the myenteric plexus and releases transmitters to cause contraction of the longitudinal muscle. The contractile response to 5-HT (3 microM) was almost completely inhibited by spantide (10 microM), a substance P antagonist, in the presence of atropine (1 microM), while spantide alone did not block 5-HT-induced contraction. Of several divalent cations including Cd2+, Co2+, Mg2+, Mn2+, Ni2+, Sr2+ and Zn2+, Cd2+ ions (10 mu-100 microM), which block L- and N-type Ca2+ channels, were most effective inhibitor of the 5-HT-induced contractions. While Sr2+ and Co2+ at a concentration of 100 microM did not have a significant effect. The order effectiveness of inhibition was Cd2+ >> Mn2+ > Mg2+ = Ni2+ = Zn2+. Bay K 8644 (1 microM), a L-type Ca2+ channel activator, did not influence the contractile response of the longitudinal muscle strip to 5-HT (3 microM). The present results suggest that 5-HT may mainly act on N-type Ca2+ channels in the myenteric neurones and cause the release of at least acetylcholine and substance P to induce contractions of the longitudinal muscle in the guinea-pig distal colon.

Please choose payment method:

(PDF emailed within 1 workday: $29.90)

Accession: 008382382

Download citation: RISBibTeXText

PMID: 7519908

Related references

The contractile effect of 5 hydroxytryptamine in the isolated longitudinal muscle strip from guinea pig ileum evidence for 2 distinct release mechanisms. Naunyn-Schmiedeberg's Archives of Pharmacology 329(1): 36-41, 1985

Some differences in contractile responses of isolated longitudinal and circular muscle from the guinea-pig stomach. Journal of Physiology 251(2): 317-331, 1975

The effect of nifedipine on the contractile responses of the longitudinal and circular muscle of the isolated guinea-pig ileum to various agonists. Archives Internationales de Pharmacodynamie et de Therapie 289(2): 165-176, 1987

Pharmacological characterization of the contractile responses to angiotensin analogues in guinea-pig isolated longitudinal muscle of small intestine. British Journal of Pharmacology 108(4): 1150-1155, 1993

Longitudinal muscle responses induced by intraluminal drug application in the isolated guinea pig colon on the nonadrenergic non cholinergic relaxation. Japanese Journal of Pharmacology 39(SUPPL): 204P, 1985

Effect of ascorbate on the contractile response induced by DMPP in guinea-pig ileal longitudinal muscle strip. European Journal of Pharmacology 89(3-4): 229-234, 1983

Influence of cations on the contractile responses of isolated guinea pig gallbladder. Japanese Journal of Pharmacology 25(SUPPL): 33P-34P, 1975

Electrical reflex responses of myenteric neurons, circular and longitudinal muscle to mucosal stimulation in isolated guinea-pig distal colon. Gastroenterology 118(4 Suppl 2 Part 1): AGA A668, 2000

Measurement of the recovery from an acid load in the isolated guinea pig papillary muscle in media free of divalent cations. Journal of Physiology (Cambridge) 452: 163P, 1992

Mode of contractile responses of smooth muscle cells in guinea pig ileal longitudinal muscle. Japanese Journal of Pharmacology 55(SUPPL 1): 316P, 1991

Contractile effects of 16-methyl analogues of PGE2 on the circular and longitudinal muscles of the guinea-pig isolated colon. Prostaglandins 42(6): 579-586, 1991

Contractile responses of the guinea pig ileal longitudinal muscle to antispasmodics. Nihon Yakurigaku Zasshi. Folia Pharmacologica Japonica 73(7): 851-859, 1977

The influence of extracellular pH upon the intracellular activity of sodium in isolated guinea pig papillary muscle perfused with a medium free of divalent cations. Journal of Physiology (Cambridge) 467(0): 329P, 1993

Contractile responses to a 23187 in guinea pig ileal longitudinal smooth muscle. Federation Proceedings 37(3): 558, 1978

Contractile response to a cannabimimetic eicosanoid, 2-arachidonoylglycerol, of longitudinal smooth muscle from the guinea-pig distal colon in vitro. European Journal of Pharmacology 444(3): 203-207, 2002