Antagonism by clonidine of the adenosine-induced inhibition of the twitch contraction of the guinea-pig oddi sphincter

1985 ◽  
Vol 108 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Takeshi Katsuragi ◽  
Takato Inoue ◽  
Tatsuo Furukawa
Keyword(s):  
Guinea Pig ◽  
Twitch Contraction ◽  
Oddi Sphincter

Potentiation of twitch contraction in guinea pig ureter by sodium vanadate

1992 ◽  
Vol 263 (5) ◽  
pp. C953-C958 ◽  
Author(s):  
S. Sunano ◽  
K. Moriyama ◽  
K. Shimamura
Keyword(s):  
Guinea Pig ◽  
Action Potential ◽  
Membrane System ◽  
Muscle Membrane ◽  
Sodium Vanadate ◽  
Duration Of Action ◽  
Twitch Contraction ◽  
Smooth Muscle Membrane ◽  
Prolongation Of Action Potential ◽  
Ca Agonist

The effect of sodium vanadate on action potential and twitch contraction of guinea pig ureter was studied and compared with that of ouabain, elevated K+, low temperature, and a Ca agonist (BAY K 8644), which can be expected to exert certain comparative effects. Sodium vanadate markedly potentiated twitch contraction. Potentiation by vanadate was associated with marked prolongation of relaxation time. Sodium vanadate caused only slight depolarization of the membrane but marked changes in action potential. The duration of action potential was prolonged and the number of oscillatory spike potentials increased. These effects were different from those of other treatments. It is concluded that prolongation of action potential and the increase in the number of spikes are the main cause of potentiation of twitch contraction by sodium vanadate. In addition, inhibition of Ca pump activity of the smooth muscle membrane system by vanadate might also be involved in potentiation of twitch contraction.

Effect of bay k 8644 on twitch contraction and membrane potential of guinea-pig ureter

1990 ◽  
Vol 183 (6) ◽  
pp. 2411
Author(s):  
K. Shimamura ◽  
K. Yamamoto ◽  
S. Osugi ◽  
S. Sunano
Keyword(s):  
Membrane Potential ◽  
Guinea Pig ◽  
Bay K 8644 ◽  
Twitch Contraction

scholarly journals Direct and indirect action of CCK-8 on the guinea-pig Oddi sphincter

1986 ◽  
Vol 40 ◽  
pp. 226
Author(s):  
Toshiro Harada ◽  
Takeshi Katsuragi ◽  
Tatsuo Furukawa
Keyword(s):  
Guinea Pig ◽  
Indirect Action ◽  
Oddi Sphincter

Tight coupling between the rate of rise of Ca2+ transient and peak twitch contraction in guinea-pig papillary muscle

1999 ◽  
Vol 377 (2-3) ◽  
pp. 199-207 ◽  
Author(s):  
Shigeki Miyamoto ◽  
Hiroshi Ozaki ◽  
Masatoshi Hori ◽  
Masao Endoh ◽  
Hideaki Karaki
Keyword(s):  
Guinea Pig ◽  
Papillary Muscle ◽  
Tight Coupling ◽  
Twitch Contraction

Effect of Contraceptive Steroids on the Endometrium of Guinea Pig: SEM study

1977 ◽  
Vol 35 ◽  
pp. 668-669
Author(s):  
Mai M. Said ◽  
Ramesh K. Nayak ◽  
Randall E. McCoy
Keyword(s):  
Guinea Pig ◽  
Reproductive Tract ◽  
Three Dimensional ◽  
Female Reproductive Tract ◽  
Human Female ◽  
Surface Ultrastructure ◽  
Transmission Electron ◽  
Sem Study ◽  
Uterine Mucosa ◽  
Group 1

Burgos and Wislocki described changes in the mucosa of the guinea pig uterus, cervix and vagina during the estrous cycle investigated by transmission electron microscopy. More recently, Moghissi and Reame reported the effects of progestational agents on the human female reproductive tract. They found drooping and shortening of cilia in norgestrel and norethindrone- treated endometria. To the best of our knowledge, no studies concerning the effects of mestranol and norethindrone given concurrently on the three-dimensional surface features on the uterine mucosa of the guinea pig have been reported. The purpose of this study was to determine the effect of mestranol and norethindrone on surface ultrastructure of guinea pig uterus by SEM.Seventy eight animals were used in this study. They were allocated into two groups. Group 1 (20 animals) was injected intramuscularly 0.1 ml vegetable oil and served as controls.

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