BACKGROUND Pyridaben, a pyridazinone derivative, is a new acaricide and insecticide for control of mites and some insects such as white flies, aphids and thrips. OBJECTIVE This study was designed to elucidate how pyridaben can affect the sperms' morphological parameters, its DNA integrity, and to estimate the effect of various quantities of pyridaben on in vitro fertilization rate. MATERIAL...

UNLABELLED Conventional myocardial perfusion PET tracers require onsite tracer production because of their short radioactive half-lives. To investigate the potential of a new (18)F-labeled pyridazinone analog ((18)F-BMS-747158-02), we characterized this tracer in a rat model of permanent and transient coronary occlusion using small-animal PET. METHODS Myocardial (18)F-BMS-747158-02 distributi...

Pimobendan, 4, 5-dihydro-6-(2-(4-methoxyphenyl)-1H-benzimidazol-5-yl)-5-methyl-3( 2-H )-pyridazinone, is a new inotropic drug that augments Ca(2+) sensitivity and inhibits phosphodiesterase in cardiomyocytes. Pimobendan is well absorbed after oral administration and is metabolized in the liver to the O-demethyl metabolite, which is also active. This study was conducted to identify the cytochrom...

The herbicide, 4 chloro-5-(methylamino)-2-(alpha,alpha,alpha,-trifluoro-m-tolyl)-3 (2H)-pyridazinone (SAN 9789), which blocks the synthesis in higher plants of colored carotenoids but not of flavins, was used to examine the involvement of carotenoids in corn seedling phototropism. It was concluded that "bulk" carotenoids are not the photoreceptor pigment based on the results that increasing con...

This study was designed to investigate the effects on single skeletal muscle fibers of a novel thienylhydrazone, referred to as LASSBio-294, which is a bioisoster of pyridazinone compounds that inhibit the cyclic AMP-specific phosphodiesterase (PDE) 4. Twitch and fatigue were analyzed in single skeletal muscle fibers isolated from either the semitendinous or the tibialis anterior muscles dissec...

Adenosine A1 receptors in the brain are believed to play an important role in brain functioning. We have discovered a novel adenosine A1 receptor antagonist, FR194921 (2-(1-methyl-4-piperidinyl)-6-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)-3(2H)-pyridazinone), and characterized the pharmacological activity in the present study. FR194921 showed potent and selective affinity for the adenosine A1 recep...

The effect of oxadiazolyl 3(2H)-pyridazinone (ODP), a new insect growth regulator, on growth of larvae of the armyworm, Pseudaletia separata Walker (Lepidoptera: Noctuidae) was evaluated in comparison to the insecticide, toosendanin, a tetranortriterpenoid extracted from the bark of Melia toosendan that has multiple effects on insects. The digestive physiological properties of these compounds o...

Diuron and bentazon are very strong inhibitors of the photosynthetic electron transport in isolated radish chloroplasts. The chlorosis producing herbicide SAN 6706 also inhibited the photosystem II dependent oxygen evolution. Aminotriazole had no effect. The inhibitor concentration for 50% inhibition of photosystem II activity was 10-7 m for diuron and 10-4 m for bentazon and SAN 6706 respectiv...