Cardiovascular aspects of pharmacology of berberine: I. α-adrenoceptor blocking action of berberine in isolated rat anococcygeus muscle and rabbit aortic strip

1987 ◽  
Vol 7 (4) ◽  
pp. 239-241 ◽  
Author(s):  
Cheng Bin ◽  
Luo Lai-yuan ◽  
Fang Da-chao ◽  
Jiang Ming-xing
Keyword(s):  
Anococcygeus Muscle ◽  
Aortic Strip ◽  
Rabbit Aortic Strip ◽  
Rat Anococcygeus Muscle ◽  
Isolated Rat

The Mechanisms of Peroxynitrite-Induced Relaxations in Isolated Rat Anococcygeus Muscle

Pharmacology ◽  
2002 ◽  
Vol 66 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Feyza Ademoğlu ◽  
Bilgen Başgut ◽  
Nurettin Abacioğlu ◽  
Iclal Çakıcı
Keyword(s):  
Anococcygeus Muscle ◽  
Rat Anococcygeus Muscle ◽  
Isolated Rat

Interaction between neurotransmitters and exogenous norepinephrine in isolated rat anococcygeus muscle

1996 ◽  
Vol 27 (2) ◽  
pp. 193-197 ◽  
Author(s):  
Ramagopal V. Mudumbi ◽  
Lonnie L. Parmeter ◽  
Margaret S. McIntyre ◽  
H.Jeff Leighton
Keyword(s):  
Anococcygeus Muscle ◽  
Rat Anococcygeus Muscle ◽  
Isolated Rat

Heat production of rat anococcygeus muscle during isometric contraction

1988 ◽  
Vol 255 (4) ◽  
pp. C536-C542 ◽  
Author(s):  
J. S. Walker ◽  
I. R. Wendt ◽  
C. L. Gibbs
Keyword(s):  
Energy Expenditure ◽  
Heat Production ◽  
Progressive Increase ◽  
Isometric Contractions ◽  
Shortening Velocity ◽  
Anococcygeus Muscle ◽  
Cross Bridge ◽  
Time Integral ◽  
Rat Anococcygeus Muscle ◽  
Cross Bridges

Heat production, unloaded shortening velocity (Vus), and load-bearing capacity (LBC) were studied in the isolated rat anococcygeus muscle during isometric contractions at 27 degrees C. The relation between the total suprabasal heat produced and the stress-time integral for isometric contractions of various durations was curvilinear, demonstrating a decreasing slope as contractile duration increased. The rate of heat production at 600 s was approximately 68% of the peak value of 6.55 mW/g that occurred at 10 s. At the same time, force rose from a mean of 92 mN/mm2 at 10 s to a value of 140 mN/mm2 at 600 s. This produced a nearly threefold increase in the economy of force maintenance. The decline in the rate of heat production was accompanied by a decline in Vus from 0.56 Lo/s at 10 s to 0.28 Lo/s at 600 s, where Lo is the length for optimal force development. This suggests the fall in the rate of heat production was caused, at least in part, by a slowing of cross-bridge kinetics. The ratio of LBC to developed tension at 10 s was not significantly different from the ratio at 600 s, suggesting that the increase in tension was due to an increased number of attached cross bridges. The decline in heat production, therefore, appears contradictory, since an increased number of attached cross bridges would predict an increased rate of energy expenditure. The observations can be reconciled if either 1) the increase in force is caused by a progressive increase in the attachment time of a constant number of cross bridges that cycle at a lower frequency or 2) the decline in energy expenditure caused by the slowing of cross-bridge cycling is sufficient to mask the increase caused by the recruitment of additional cross bridges.

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