Abstract：
:In using pharmacologic stimuli, force-velocity (FV) curves are usually obtained by the method of quick release (QR) and redevelopment of shortening at peak tetanic tension; the advantage of the method being that the active state is at maximum. However, the QR may itself reduce the intensity of the active state and result in reduced values of FV constants. We tested this by delineating FV curves in canine tracheal smooth muscle using both conventional afterloaded isotonic contractions (ALI), and redevelopment of shortening after QR methods. For both these studies a supramaximal tetanizing electrical stimulus was used. The analysis of 11 experiments revealed that the latter method resulted in statistically significant reductions of all FV constants except for Po (maximum isometric tetanic tension). The means and standard errors for the sets of constants for the ALI and QR, respectively, are as follows: Vmax (maximum velocity of shortening) = 0.275 lo (optimal muscle length)/s +/- 0.024 (SE), and 0.216 lo/s + 0.023; a (hyperbolic constant with units of force) = 294 g/cm2 +/- 35 and 236 g/cm2 +/- 32; b (hyperbolic constant with units of velocity) = 0.059 lo +/- 0.004 and 0.039 lo/s +/- 0.005; a/Po = 0.214 +/- 0.028 and 0.182 +/- 0.026; and Po = 1.362 kg/cm2 +/- 0.106 and 1.294 kg/cm2 +/- 0.097. These data clearly show that the quick-release method for measuring force-velocity relationships in canine smooth muscle results in significant underestimates of muscle shortening properties.
journal_name
Can J Physiol Pharmacoljournal_title
Canadian journal of physiology and pharmacologyauthors
Stephens NLdoi
10.1139/y85-008subject
Has Abstractpub_date
1985-01-01 00:00:00pages
48-51issue
1eissn
0008-4212issn
1205-7541journal_volume
63pub_type
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journal_title：Canadian journal of physiology and pharmacology
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y91-053
更新日期：1991-03-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
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journal_title：Canadian journal of physiology and pharmacology
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journal_title：Canadian journal of physiology and pharmacology
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
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更新日期：1985-09-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
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doi：10.1139/y82-103
更新日期：1982-05-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
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更新日期：1985-07-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y90-238
更新日期：1990-12-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y90-176
更新日期：1990-09-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
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doi：10.1139/y2012-126
更新日期：2012-11-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y83-106
更新日期：1983-07-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y91-066
更新日期：1991-03-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
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更新日期：2005-10-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
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pub_type： 杂志文章
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章,评审
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更新日期：2009-02-01 00:00:00
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pub_type： 杂志文章
doi：10.1139/Y08-090
更新日期：2008-11-01 00:00:00
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pub_type： 杂志文章
doi：10.1139/y90-208
更新日期：1990-10-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y92-208
更新日期：1992-11-01 00:00:00
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pub_type： 杂志文章
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更新日期：2020-03-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：
更新日期：1999-11-01 00:00:00
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journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y92-069
更新日期：1992-04-01 00:00:00
abstract：:We studied the role of enteric opioid neurons in the spontaneous motility of the longitudinal muscle in the isolated puppy ileum. Regular fluctuations in tone that rose above and returned to the basal level occurred at an interval of 4.7 +/- 0.3 min. Naloxone (10(-8) and 10(-7) M) reduced the spontaneous tonic contrac...
journal_title：Canadian journal of physiology and pharmacology
pub_type： 杂志文章
doi：10.1139/y87-301
更新日期：1987-09-01 00:00:00
