Related Experiment Video
Updated: Jun 7, 2026

Genetically-encoded Molecular Probes to Study G Protein-coupled Receptors
Published on: September 13, 2013
The mechanism of (R,R) ZX-5 on increasing NO release
1Department of Marine Pharmacy, College of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, Jiangsu Province, China; E-Mails: xuhanmei@yahoo.com.cn (H.-M.X.); tiandezhijian@126.com (J.W.); panli0225@163.com (L.P.); hongyin7719@sina.com (H.L.); wwq1979@163.com (W.W.).
Abstract:
(R,R) ZX-5 has been proven to have positive effects on choroidal blood flow without affecting the sclera and ciliary bodies in New Zealand white rabbits. This study was designed to investigate the mechanisms of (R,R) ZX-5 on improving the choroidal blood flow and promoting NO production. HUVECs (human umbilical vein endothelial cells) were used to determine the production of eNOS, p-eNOS, AKT and Erk1/2 by Western blot analysis. iNOS and eNOS mRNA levels were investigated by RT-PCR and the effect of (R,R) ZX-5 on NO production were determined by eNOS activity assay. We found (R,R) ZX-5 upregulated protein expression of eNOS and iNOS, increased NO production, and reduced ERK and Akt protein level. Therefore, (R,R) ZX-5 may promote the choroidal blood flow in New Zealand white rabbits without affecting the blood flow in the iris or ciliary bodies via increasing NO production. These results suggest that (R,R) ZX-5 may function to cure and prevent Age-related macular degeneration (AMD).
Related Concept Videos
Rate-Determining Steps
In a multistep reaction mechanism, one of the elementary steps progresses significantly slower than the others. This slowest step is called the rate-limiting step (or rate-determining step). A reaction cannot proceed faster than its slowest step, and hence, the rate-determining step limits the overall reaction rate.
The concept of rate-determining step can be understood from the analogy of a 4-lane freeway with a short-stretch of traffic-bottleneck caused due to...
Multi-Step Reactions
Nitric Oxide Signaling Pathway
GPCR Desensitization
Desensitization and Tachyphylaxis
Several...
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism

