The relative importance of extracellular and intracellular calcium in the responses of the human vas deferens to noradrenaline and potassium: a study using Ca(2+)-deprivation and Ca(2+)-antagonists.

@article{Amobi1993TheRI,
  title={The relative importance of extracellular and intracellular calcium in the responses of the human vas deferens to noradrenaline and potassium: a study using Ca(2+)-deprivation and Ca(2+)-antagonists.},
  author={N. I. B. Amobi and C. H. Smith},
  journal={Journal of autonomic pharmacology},
  year={1993},
  volume={13 3},
  pages={
          177-92
        }
}
1. Mechanical responses of the human vas deferens, activated by noradrenaline (50-100 microM) or high potassium (130 mM), showed either biphasic shortening or lengthening or a combination of initial shortening and lengthening. These are interpreted as representing the contractions of longitudinal and circular muscle respectively. 2. Caffeine (10-20 mM) induced only shortening responses which were 86% (SE 34, n = 7) of that caused by noradrenaline (100 microM). 3. The calcium channel antagonists… 
11 Citations

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Differential inhibition in the human vas deferens by phenoxybenzamine: a possible mechanism for its contraceptive action.

The results suggest a mechanism for the male contraceptive action of phenoxybenzamine by a selective blockade of longitudinal but not circular muscle contractions in the human vas deferens.

Ryanodine- and cyclopiazonic acid-sensitive components in human vas deferens contractions to noradrenaline.

Results suggest that circular muscle contraction by NA and the initial component of longitudinal muscle to NA both utilize an intracellular pool of calcium that is triggered via a ryanodine-sensitive mechanism and replenished via a CPA-sensitive Ca2+-ATPase.

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The contractile responses of isolated rat thoracic aortic strips to norepinephrine (NE) and KCl in the absence of extracellular calcium were studied using 1,2-bis-(2-dicarboxymethylaminoethoxy)ethane

EFFECTS OF SOME ORGANIC CALCIUM ANTAGONISTS AND OTHER PROCEDURES AFFECTING Ca2+ TRANSLOCATION ON KCl‐INDUCED CONTRACTIONS IN THE RAT VAS DEFERENS

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