scholarly journals Effects of Various Selective Phosphodiesterase Inhibitors on Carbachol-Induced Contraction and Cyclic Nucleotide Contents in the Guinea Pig Gall Bladder

2005 ◽  
Vol 67 (7) ◽  
pp. 659-665 ◽  
Author(s):  
Takeharu KANEDA ◽  
Akitoshi WATANABE ◽  
Kazumasa SHIMIZU ◽  
Norimoto URAKAWA ◽  
Shinjiro NAKAJYO
Keyword(s):  
Gall Bladder ◽  
Guinea Pig ◽  
Cyclic Nucleotide ◽  
Phosphodiesterase Inhibitors

scholarly journals The identification of a new cyclic nucleotide phosphodiesterase activity in human and guinea-pig cardiac ventricle. Implications for the mechanism of action of selective phosphodiesterase inhibitors

1987 ◽  
Vol 241 (2) ◽  
pp. 535-541 ◽  
Author(s):  
M L Reeves ◽  
B K Leigh ◽  
P J England
Keyword(s):  
Cyclic Amp ◽  
Guinea Pig ◽  
Cardiac Muscle ◽  
Cyclic Gmp ◽  
Cyclic Nucleotide ◽  
Gel Filtration ◽  
Phosphodiesterase Inhibitors ◽  
Cyclic Nucleotide Phosphodiesterase ◽  
Kinetic Properties ◽  
Cardiac Ventricle

Four cyclic nucleotide phosphodiesterase (PDE) activities were separated from low-speed supernatants of homogenates of human cardiac ventricle by DEAE-Sepharose chromatography, and designated PDE I-PDE IV in order of elution with an increasing salt gradient. PDE I was a Ca2+/calmodulin-stimulated activity, and PDE II was an activity with a high Km for cyclic AMP which was stimulated by low concentrations of cyclic GMP. Human ventricle PDE III had Km values of 0.14 microM (cyclic AMP) and 4 microM (cyclic GMP), and showed simple Michaelis-Menten kinetics with both substrates. PDE IV is a previously unrecognized activity in cardiac muscle, the human enzyme having Km values of 2 microM (cyclic AMP) and 50 microM (cyclic GMP). PDE III and PDE IV were not activated by cyclic nucleotides or calmodulin. Four PDE activities were also isolated from guinea-pig ventricle, and had very similar kinetic properties. By gel filtration, the Mr of PDE III was 60,000, and that of PDE IV 45,000. The drug SK&F 94120 selectively and competitively inhibited PDE III with a Ki value of 0.8 microM (human), showing simple hyperbolic inhibition kinetics. Rolipram (Schering ZK 62711) and Ro 20-1724 (Roche), which have previously been reported to inhibit PDE III-like activities strongly, were shown to be weak inhibitors of human and guinea-pig PDE III enzymes (Ki values greater than 25 microM), but potent inhibitors of PDE IV [Ki values 2.4 microM (Rolipram) and 3.1 microM (Ro 20-1724) with human PDE IV]. The inhibition in all cases demonstrated simple hyperbolic competition. These observations suggest that the previously reported complex inhibition of PDE III-type activities from cardiac muscle was caused by incomplete separation of the PDE III from other enzymes, particularly PDE IV.

Effects of ethanol on contractile response of gall bladder isolated from guinea pig

1993 ◽  
Vol 248 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Hidehisa Masui ◽  
Ichiro Wakabayashi ◽  
Katsuhiko Hatake ◽  
Sachiko Yoshimoto ◽  
Kunihiro Sakamoto
Keyword(s):  
Gall Bladder ◽  
Guinea Pig ◽  
Contractile Response
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