木崎 静子 ・安孫子 保 It has been reported that spleen strips contract with an addition of adrenaline (1 3), noradrenaline (3), acetylcholine (1-3), histamine (1-2) or 5-hydroxytryptamine (2) to the bath medium. The adrenaline-induced contraction of the spleen strips can be block ed by alpha-adrenergic blocking agents (1-4). According to Bickerton (4), isoproterenol, which stimulates beta-adrenergic rec...

We examined the hypothesis that contraction of the carotid arteries to serotonin is normally inhibited by endothelial NO synthase (eNOS) and is enhanced in mice lacking the gene for eNOS. Because the influence of eNOS may vary with the sex of the mouse, we also tested whether responses to serotonin were dependent on sex. We studied carotid arteries in vitro from littermate control (eNOS(+/+)) m...

OBJECTIVE The use of drugs with herbal origin is increasing for treatment of gastrointestinal (GI) disorders. Rosa damascena (R. damascena) is a well-known plant suggested to have beneficial effect on GI system. In this study, the effect of aqueous fraction of R. damascena on the contractions of isolated guinea pig ileum was investigated. MATERIALS AND METHODS Aqueous fraction of plant was ob...

In our previous study, we found that spermine and putrescine inhibited spontaneous and acetylcholine (ACh)-induced contractions of guinea-pig stomach via inhibition of L-type voltage-dependent calcium current (VDCC(L)). In this study, we also studied the effect of spermidine on mechanical contractions and calcium channel current (I(Ba)), and then compared its effects to those by spermine and pu...

The arterial system of the marine mollusc Aplysia consists of three major arteries. One of them, the abdominal aorta, has a sphincter (the vasoconstrictor muscle) at the base of the artery. Contraction of this muscle reduces the blood flow into the abdominal aorta, thereby, playing a role in the regulation of the blood distribution in Aplysia. Here, we show the contractility of the vasoconstric...

In this study we investigated the effects of endothelium removal and L-NAME on responses to α-adrenoceptor agonists. Male Wistar rats were killed by overdose with pentobarbitone sodium, after which the left and right common carotid arteries were removed. Rings of arteries 3-4 mm in length were cut from each vessel and then mounted in 10 mL isolated organ bath, bathed in Krebs maintained at ...

Acetylstrophanthidin, 1.0 to 10.0 fig/ml, caused contraction of strips of the lateral saphenous vein of the dog in an organ bath at 37°C. The superior mesenteric vein, which exhibited spontaneous activity in the organ bath, responded to acetylstrophanthidin with an almost immediate increase in tension and an increased frequency of contractions; this was followed by a sustained contraction which...

Although the role of protein kinase C (PKC) has been suggested in agonist-induced bronchial smooth muscle contraction, the PKC isoform(s) involved in this phenomenon is not clear now. In the present study, the effects of three PKC inhibitors, GFI092603X, G66976 and rottlerin on acetylcholine (ACh)-inducecl bronchial smooth inuscle contractien were examined to identify the PKC isoform(s) involve...

in this study we investigated the effects of endothelium removal and l-name on responses to α-adrenoceptor agonists. male wistar rats were killed by overdose with pentobarbitone sodium, after which the left and right common carotid arteries were removed. rings of arteries 3-4 mm in length were cut from each vessel and then mounted in 10 ml isolated organ bath, bathed in krebs maintained at 37°c...

This study was designed to investigate the effects of polyamines on mechanical contraction and voltage-dependent calcium current (VDCC) of guinea-pig gastric smooth muscle. Mechanical contraction and calcium channel current I(Ba) were recorded by isometric tension recording and whole-cell patch clamp technique. Spermine, spermidine and putrescine inhibited spontaneous contraction of the gastric...