9-cis-Retinal is a retinoid with Kd of 8 nM and 5 nM for cellular retinol binding protein-I (CRBP-1) and CRBP-II, respectively. 9-cis-Retinal accelerates the differentiation and maturation of rod photoreceptors in retinal organoids, reduces the toxicity of unliganded opsins, and can be used to study congenital stationary night blindness caused by G90D rhodopsin.

b>METHODS: The binding of 9-cis-retinol, 9-cis-retinal, and 9-cis-RA to CRBPI and CRBPII was monitored through fluorescence spectroscopy, and the data were analyzed using nonlinear regression to determine the apparent dissociation constant K'(d) .
RESULTS: CRBPI and CRBPII bind to 9-cis-retinol (K'(d), 11nM and 68nM) and 9-cis-retinal (K'(d), 8nM and 5nM) respectively with high affinity; CRBPI or CRBPII have not been observed yet. Significant binding of CRBPII to 9-cis-RA. [1]

b>METHODS: After recording baseline ERG, IRBP-deficient mice were allowed to rest for 12 hours, and 0.375 mg of 9-cis-retinal was injected intraperitoneally. ERG before and after were analyzed to test 11-cis-retinal in cones of IRBP-deficient mice. retinal defects.
RESULTS: 9-cis-retinal treatment significantly increased cone photoreceptor responses; the cones of IRBP-deficient mice were particularly sensitive to exogenous 9-cis-retinal, and the recovery of cone photoreceptor function to WT levels indicated that IRBP deletion had minimal Cone dysfunction in mice is caused by 11-cis-retinal deficiency. [4]