| Title: |
Effects of nifedipine on hepatic blood volume in cats: indirect venoconstriction and absence of inhibition of postsynaptic α 2 -adrenoceptor responses |
| Authors: |
Segstro, R.; Seaman, K. L.; Innes, I. R.; Greenway, C. V. |
| Source: |
Canadian Journal of Physiology and Pharmacology ; volume 64, issue 5, page 615-620 ; ISSN 0008-4212 1205-7541 |
| Publisher Information: |
Canadian Science Publishing |
| Publication Year: |
1986 |
| Description: |
Intravenous administration of hypotensive doses (30–200 μg/kg) of nifedipine to cats anesthetized with pentobarbital caused an increase in cardiac output accompanied by hepatic venoconstriction. The hepatic venoconstriction and the increase in cardiac output were abolished in animals in which the hepatic sympathetic nerves were cut, the adrenal glands were excluded, and the kidneys were removed. This contrasts with the indirect hepatic venoconstrictor action of isoproterenol which was shown previously not to be abolished by these procedures. Further experiments showed that the hepatic venoconstrictor effect of nifedipine was blocked by removal of the kidneys, but not by removal of the hepatic sympathetic nerves and adrenals. These results support the hypothesis that venoconstriction plays an important role when drugs produce increased cardiac output. In nephrectomized animals, nifedipine had no direct effects on hepatic blood volume and it did not alter the effects of infusions of norepinephrine on hepatic blood volume, which have previously been shown to be mediated through α 2 -adrenoceptors. However, it did reduce the hepatic venous responses to hepatic sympathetic nerve stimulation by 30%. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| DOI: |
10.1139/y86-102 |
| Availability: |
https://doi.org/10.1139/y86-102; http://www.nrcresearchpress.com/doi/pdf/10.1139/y86-102 |
| Rights: |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
| Accession Number: |
edsbas.4910D0E3 |
| Database: |
BASE |