Rerentty, Quirion and Pert [I] reported that certain calcium antagonists displace ~3~]pkeu~~c~id~~e ~~3~]P~P~ ~~~d~~g in rat brain. They found fkat verapamif, and its methxy derivative, D-600), were potent displacers of @I]PCP binding with X; values of 1.4 and 1.7 #VI respectively. In contrast, two calcium antagonists of the 1,4-dihydropyridine series, nifedipine and nitrendipine, were very wea...

Cerebral blood flow (CBF) in the rat was monitored by a venous outflow technique with an extracorporeal circulation, which allows for the continuous recording of flow over periods of several hours. Brief periods of anoxia increase the rate of flow. The dihydropyridine calcium antagonists did not affect basal flow rate and depressed the increase in CBF elicited by anoxia. These findings may have...

NMDA-induced intrinsic voltage oscillations depend on L-type calcium channels in spinal motoneurons of adult turtles. J. Neurophysiol. 80: 3380-3382, 1998. In a slice preparation from adult turtles, bath-applied N-methyl-D-aspartate (NMDA) induced rhythmic activity in spinal motoneurons. The underlying intrinsic oscillation in membrane potential was revealed in the presence of tetrodotoxin (TTX...

Considerable progress in the medical as well as the surgical management of angina has been made in the past decade. An appreciation of the pharmacokinetics of the "oldest" antianginal drugs, the nitrates, has lead to the development of effective long acting preparations and novel techniques of administration. On the other hand, calcium antagonists represent a new approach to the treatment of an...

The usefulness of calcium antagonists to reduce restenosis after coronary angioplasty remains uncertain despite 5 randomized trials involving 919 patients. Review and meta-analysis of these trials are performed to provide insight into whether calcium antagonists reduce angiographic restenosis. In aggregate, these trials suggest that patients treated with calcium antagonists had approximately a ...

I47 Tsien’s group classified these channels as ‘N, ‘T, In the 1960s the research groups of Fleckenstein and Godfraind defined ‘calcium antagonists’ as agents which blocked the entry of calcium into cells via voltage-dependent calcium channels. In a literature search we found 74 compounds in various stages of clinical or preclinical development classed as ‘calcium antagonists’. Since the initial...

The effects of drugs were evaluated in 47 cases with variant angina (VA), 19 with resting angina showing ST depression (RA), and 84 with unstable angina (UA). In VA patients, calcium antagonists were effective in 87.1% of the cases, while other drugs were effective in 56.3%. The difference was statistically significant. In RA patients, calcium antagonists were effective in 80.0% of the cases an...

The L type calcium channel agonist (+/-)Bay K 8644 has been reported to cause characteristic motor abnormalities in adult mice. The current study shows that administration of this drug can also cause the unusual phenomenon of self-injurious biting, particularly when given to young mice. Self-biting is provoked by injecting small quantities of (+/-)Bay K 8644 directly into the lateral ventricle ...

To investigate the channels and neurotransmitters in the ventrolateral medulla (VLM) oblongata that are responsible for the maintenance of sympathetic tone and cardio-respiratory reflex regulation. Microinjections of excitant amino acid (glutamate, 100 nl, 100 mM), calcium channel blockers, agonists and antagonists were made throughout the VLM in anaesthetized rats. Arterial blood pressure, sym...