Comparative Effects of theN-Methyl-d-aspartate Antagonist MK-801 and the Calcium Channel Blocker KB-2796 on Neurologic and Metabolic Recovery after Spinal Cord Ischemia

1998 ◽  
Vol 149 (1) ◽  
pp. 203-208 ◽  
Author(s):  
Viera Danielisová ◽  
Mikuláš Chavko
2003 ◽  
pp. 425-432 ◽  
Author(s):  
T. Winkler ◽  
Hari Shanker Sharma ◽  
E. Stålberg ◽  
R. D. Badgaiyan ◽  
T. Gordh ◽  
...  

1996 ◽  
Vol 84 (3) ◽  
pp. 636-643 ◽  
Author(s):  
Keiichi Omote ◽  
Mikito Kawamata ◽  
Osamu Satoh ◽  
Hiroshi Iwasaki ◽  
Akiyoshi Namiki

Background Four different voltage-dependent calcium channels (L-, N-, T-, and P-types) are distinguished in the central nervous system. Both L- and N-type calcium channels have been implicated in the release of neurotransmitters from sensory neurons in the spinal cord. It has been demonstrated that intrathecal L-type calcium channel blockers, which alone do not exhibit any antinociceptive effects, potentiate the antinociceptive effect of intrathecal morphine. The current study was designed to investigate the antinociceptive effects of the intrathecally administered N-type calcium channel blocker, omega-conotoxin GVIA (omega-CgTx). The interaction between morphine and omega-CgTx at the level of the spinal cord also was examined. Methods In male Sprague-Dawley rats, lumbar intrathecal catheters were chronically implanted. Tail flick and mechanical paw pressure tests were used to assess thermal and mechanical nociceptive thresholds, respectively. Morphine, omega-CgTx, or a combination of morphine and omega-CgTx was administered intrathecally, and the nociceptive thresholds were determined. Isobolographic analyses were used to define the nature of the functional interactions between morphine and omega-CgTx. Results Intrathecal omega-CgTx produced antinociception in a dose- and time-dependent manner. Isobolographic analyses revealed that intrathecal omega-CgTx and morphine interacted synergistically in both nociceptive tests. Conclusions This study indicates the importance of the N-type calcium channel in the spinal cord on nociception and suggests the functional interaction between the N-type calcium channel blocker and opioid at the level of the spinal cord.


1996 ◽  
Vol 134 (2) ◽  
pp. 477-486 ◽  
Author(s):  
P Liesi ◽  
J M Wright

The weaver mutation impairs migration of the cerebellar granular neurons and induces neuronal death during the first two weeks of postnatal life. To elucidate the molecular mechanisms for the impaired neuronal migration, we investigated the rescue mechanisms of the weaver (wv/wv) granule neurons in vitro. We found that Fab2 fragments of antibodies against a neurite outgrowth domain of the B2 chain of laminin enhanced neurite outgrowth and neuronal migration of the weaver granule neurons on a laminin substratum and in the established cable culture system. The rescue of the weaver granule neurons by antibodies against the B2 chain of laminin may result from the neutralizing effect of these antibodies against the elevated B2 chain levels of the weaver brain. The L-type calcium channel blocker, verapamil (1-5 microM), also rescued the weaver granule neurons. High concentrations of MK-801 (10-20 microM), a glutamate receptor antagonist and voltage-gated calcium channel blocker, rescued the weaver granule neurons similar to verapamil, but low concentrations of MK-801 (1 microM) had no rescue effect. Simultaneous patch-clamp studies indicated that the weaver granule neurons did not express functional N-methyl-D-aspartate receptors further indicating that the rescue of the weaver granule neurons by MK-801 resulted from its known inhibition of voltage-gated calcium channels. The present results indicate that antibodies against the B2 chain of laminin, verapamil, and high concentrations of MK-801 protect the weaver granule neurons from the otherwise destructive action of the weaver gene. Thus, both the laminin system and calcium channel function contribute to the migration deficiency of the weaver granule neurons.


1990 ◽  
Vol 122 (3) ◽  
pp. 403-408
Author(s):  
Ph. Touraine ◽  
P. Birman ◽  
F. Bai-Grenier ◽  
C. Dubray ◽  
F. Peillon ◽  
...  

Abstract In order to investigate whether a calcium channel blocker could modulate the protein kinase C activity in normal and estradiol pretreated rat pituitary, female Wistar rats were treated or not (controls) with ± PN 200-110 (3 mg · kg−1 · day−1, sc) for 8 days or with estradiol cervical implants for 8 or 15 days, alone or in combination with PN 200-110 the last 8 days. Estradiol treatment induced a significant increase in plasma prolactin levels and pituitary weight. PN 200-110 administered to normal rats did not modify these parameters, whereas it reduced the effects of the 15 days estradiol treatment on prolactin levels (53.1 ± 4.9 vs 95.0 ±9.1 μg/l, p<0.0001) and pituitary weight (19.9 ± 0.4 vs 23.0 ± 0.6 mg, p <0.001), to values statistically comparable to those measured after 8 days of estradiol treatment. PN 200-110 alone did not induce any change in protein kinase C activity as compared with controls. In contrast, PN 200-110 treatment significantly counteracted the large increase in soluble activity and the decrease in the particulate one induced by estradiol between day 8 and day 15. We conclude that PN 200-110 opposed the stimulatory effects of chronic in vivo estradiol treatment on plasma prolactin levels and pituitary weight and that this regulation was related to a concomitant modulation of the protein kinase C activity.


2020 ◽  
Vol 16 ◽  
Author(s):  
Seiji Umemoto ◽  
Toshio Ogihara ◽  
Masunori Matsuzaki ◽  
Hiromi Rakugi ◽  
Kazuyuki Shimada ◽  
...  

Background: In the trial known as COPE (Combination Therapy of Hypertension to Prevent Cardiovascular Events) three benidipine (a calcium channel blocker; CCB) regimens were compared. Hypertensive Japanese outpatients aged 40–85 years (n=3,293) who did not achieve the target blood pressure of <140/90 mmHg with benidipine 4 mg/day were treated with the diuretic thiazide (n=1,094) or a β-blocker (n=1,089) or an additional angiotensin receptor blocker (ARB; n=1,110). A significantly higher incidence of hard cardiovascular composite endpoints and of fatal or non-fatal strokes was observed in the benidipine-β-blocker group compared to the benidipine-thiazide group. Objective and Methods: We further evaluated the treatment effects of the three benidipine-based regimens on vascular and renal events in a sub-analysis of the COPE patients. Results: A total of 10 vascular events (0.8 per 1,000 person-years) including one aortic dissection (0.1 per 1,000 person-years) and nine cases of peripheral artery disease (0.8 per 1,000 person-years) were documented, as was a total of seven renal events (0.6 per 1,000 person-years). No significant differences in vascular and renal events were revealed among the three treatment groups: vascular events p=0.92 renal events p=0.16 log-rank test. Conclusions: Blood pressure-lowering therapy with benidipine combined with an ARB, β-blocker, or thiazide was similarly effective in the prevention of vascular and renal events in hypertensive outpatients, although there is no enough these events to compare the difference in the three treatment groups.


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