A re-investigation of questionable subclassifications of presynaptic α2-autoreceptors: rat vena cava, rat atria, human kidney and guinea-pig urethra

1997 ◽  
Vol 356 (6) ◽  
pp. 721-737 ◽  
Author(s):  
A.-U. Trendelenburg ◽  
Igor Sutej ◽  
Christian Andreas Wahl ◽  
Gerhard Josef Molderings ◽  
Lars Christian Rump ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Vena Cava ◽  
Human Kidney ◽  
Rat Atria ◽  
Rat Vena Cava

17-Oxidoreduction of 17β-Estradiol, Estrone and Their 3-Sulfates by Kidney Slices from Guinea Pig and Human

1975 ◽  
Vol 53 (12) ◽  
pp. 1333-1336 ◽  
Author(s):  
R. Hobkirk ◽  
Mona Nilsen ◽  
Barbara Jennings
Keyword(s):  
Guinea Pig ◽  
Marked Reduction ◽  
Human Kidney ◽  
Kidney Cortex ◽  
Limited Extent ◽  
Tissue Slices ◽  
Ample Evidence ◽  
Sulfatase Activity ◽  
17Β Estradiol ◽  
Dehydrogenation Reactions

Slices of whole kidney and kidney cortex from the female guinea pig catalyzed a marked reduction of estrone 3-sulfate (E13S) and estrone (E1) to 17β-estradiol 3-sulfate (E23S) and 17β-estradiol (E2), respectively, as well as the reverse (dehydrogenation) reactions. Slices of medulla did not appear active in E23S–E13S interconversion but did possess the ability to interconvert E2 and E1, besides possessing considerable sulfatase activity. The use of [3H-35S]E13S and [3H-35S]E23S as substrates, together with a demonstrated lack of estrogen sulfate synthesis by the tissue slices, provided ample evidence that the intact sulfates were involved in direct oxidoreduction. Slices of human kidney cortex catalyzed the reduction of E13S to a very limited extent. Slices of whole kidney and of cortex from guinea pig formed small amounts of estrogen glucuronide(s).

Influence of spaceflight, hindlimb suspension, and venous occlusion on alpha 1-adrenoceptors in rat vena cava

1995 ◽  
Vol 78 (5) ◽  
pp. 1882-1888 ◽  
Author(s):  
I. Sayet ◽  
G. Neuilly ◽  
J. Mironneau ◽  
C. Mironneau
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Dissociation Constant ◽  
Binding Capacity ◽  
Vena Cava ◽  
Venous Occlusion ◽  
Hindlimb Suspension ◽  
Scatchard Analysis ◽  
Kinase C ◽  
Rat Vena Cava

Effects of hindlimb suspension, spaceflight, and venous occlusion were examined in isolated strips from rat vena cava by using both [3H]prazosin-binding and contraction responses evoked by norepinephrine. Sensitivity to norepinephrine was decreased without modification of the maximal contractile response. Furthermore, the high K(+)-induced contractions were not affected, suggesting that there was no interference with voltage-dependent Ca2+ channels. The sensitivity of the norepinephrine-induced contraction to prazosin was decreased, and Scatchard analysis of [3H]prazosin binding indicated an increase in the dissociation constant without variation in maximal binding capacity. A similar increase in the dissociation constant was obtained in control rats after pretreatment with 3 microM norepinephrine or 0.1 microM phorbol 12,13-dibutyrate to desensitize the protein kinase C. This effect was completely abolished in the presence of GF-109203X, a selective inhibitor of protein kinase C. Taken together, these data indicate that altered gravity conditions induce a desensitization of alpha 1B-adrenoceptors depending on increased protein kinase C activity. This effect can be mimicked by venous occlusion and may be responsible for reduced contractile responses to norepinephrine.

A model for passive elastic properties of rat vena cava

2007 ◽  
Vol 40 (14) ◽  
pp. 3130-3145 ◽  
Author(s):  
Georg Wolfgang Desch ◽  
Hans Werner Weizsäcker
Keyword(s):  
Elastic Properties ◽  
Vena Cava ◽  
Rat Vena Cava

Microfibrillar Elastic Polymer Wrapping of Rat Vena Cava for the Study of Engineered Arterial Vein Grafts

2010 ◽  
Author(s):  
Qiang Wang ◽  
Wei He ◽  
Yi Hong ◽  
William R. Wagner ◽  
David A. Vorp
Keyword(s):  
Saphenous Vein Graft ◽  
Vena Cava ◽  
Wall Stress ◽  
Cellular Injury ◽  
Vein Grafts ◽  
Ample Opportunity ◽  
Circumferential Wall Stress ◽  
Rat Vena Cava ◽  
Elastic Polymer ◽  
Polymer Wrapping

The autologous saphenous vein graft remains the graft of choice for 95% of surgeons performing coronary artery or peripheral bypass procedures. Within the first 5 years after implantation, 20%–40% of arterial vein grafts (AVG) fail due to intimal hyperplasia (IH)1. This adverse pathological response by AVGs may be in part due to their abrupt exposure to the significantly elevated circumferential wall stress associated with the arterial system2. We believe that if an AVG is given an ample opportunity to adapt and remodel to the stresses of the arterial environment, cellular injury may be reduced, thus limiting the initiating mechanisms of IH.

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