Digoxin-Induced Reversible Dysfunction of the Cone Photoreceptors in Monkeys

Kinoshita, Junzo; Iwata, Noriaki; Kimotsuki, Tomofumi; Yasuda, Mitsuya

doi:10.1167/iovs.13-13296

Cited by 12 publications

(8 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Immediately before the photopic ERG section of the standard full-field ERGs recording period, responses for the a-wave analysis were recorded in the same manner as that described in our previous reports. 12,13 Briefly, three steps of stimuli were used to elicit the rod-and cone-driven response in the fully dark-adapted state. Thereafter, the cone-driven response in the fully dark-adapted state was elicited by means of a transient rod-saturation procedure, in which the white test stimulus was delivered 500 ms after the conditioning white flash of 4.0 log scot td-s. To elicit the cone-driven response, three steps of test stimuli, which were identical to those used to elicit the rod-and conedriven response, were used.…”

Section: Erg Recording and Analysismentioning

confidence: 99%

N-Methyl-N-Nitrosourea–Induced Acute Alteration of Retinal Function and Morphology in Monkeys

Kinoshita

Iwata

Maejima

et al. 2015

Invest. Ophthalmol. Vis. Sci.

Self Cite

View full text Add to dashboard Cite

PURPOSE. The purpose of this study was to investigate both functional and morphologic alteration of the retina acutely induced by N-methyl-N-nitrosourea (MNU) in monkeys.METHODS. The MNU was administered intravenously at a single dose of 40 mg/kg to six cynomolgus monkeys, and standard full-field electroretinograms (ERGs) were recorded 1, 3, and 7 days after dosing. In addition, the rod and cone a-waves in response to high-intensity flashes were analyzed by the a-wave fitting model (a-wave analysis). The photopic negative response (PhNR) was also recorded at the same time points. Furthermore, the retinas of two animals each were examined histopathologically 1, 3, or 7 days after dosing. RESULTS.The MNU attenuated all the standard full-field ERGs including the rod-driven and cone-driven responses; in the combined rod-cone response, the b-wave was more affected than the a-wave. In the a-wave analysis, the sensitivity parameters (S) of the rod and cone awaves had decreased on the day after dosing and remained unchanged thereafter. The maximum response parameter (R max ) of the rod a-wave gradually decreased. On the other hand, the R max in the cone a-wave transiently increased on the day after dosing and decreased thereafter; the PhNR amplitude showed a similar time course change. Histopathologically, the retinal lesion on the day after dosing mainly consisted of pyknosis and karyorrhexis in the photoreceptor nucleus. Depletion of some photoreceptor nuclei, and shortening and disorientation of the photoreceptor segments became prominent at 3 and 7 days after dosing. Localization of degenerated photoreceptors was consistent with that of rhodopsin-positive photoreceptors, resulting in a well-preserved central fovea. CONCLUSIONS.Our results indicated that MNU acutely induced rod-dominant photoreceptor degeneration in monkey retinas, but the photoreceptor function was impaired in both the rods and cones. Functional involvement of the postreceptoral components was also indicated.

show abstract

Section: Erg Recording and Analysismentioning

confidence: 99%

N-Methyl-N-Nitrosourea–Induced Acute Alteration of Retinal Function and Morphology in Monkeys

Kinoshita

Iwata

Maejima

et al. 2015

Invest. Ophthalmol. Vis. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The dog also suffered suspected digitalis‐related retinopathy. Visual disturbances have been reported in people and laboratory animals with digoxin toxicosis; they are reversible with withdrawal of the drug . It is speculated that the visual disturbances are due to inhibition of Na + /K + ATPase that induces concentration‐dependent reductions in the light response of photoreceptors …”

Section: Discussionmentioning

confidence: 99%

Successful use of digoxin‐specific immune Fab in the treatment of severeNerium oleandertoxicosis in a dog

Pao‐Franco¹,

Weatherton²,

DeClementi

et al. 2017

J Vet Emergen Crit Care

View full text Add to dashboard Cite

show abstract

“…Immediately before the photopic ERG section of the standard full-field ERGs recording period, responses for the a-wave analysis were recorded in the same manner as that described in our previous report. 16 Briefly, three steps of stimuli were used to elicit the rod-and conedriven response in the fully dark-adapted state. Thereafter, the cone-driven response in the fully dark-adapted state was elicited by means of a transient rod-saturation procedure, in which the white test stimulus was delivered 500 ms after the conditioning white flash of 4.0 log scot td-s. To elicit the conedriven response, three steps of test stimuli, which were identical to those used to elicit the rod-and cone-driven response, were used.…”

Section: Recording and Analysismentioning

confidence: 99%

Sildenafil-Induced Reversible Impairment of Rod and Cone Phototransduction in Monkeys

Kinoshita¹,

Iwata²,

Shimoda³

et al. 2015

Investigative Ophthalmology & Visual Science

View full text Add to dashboard Cite

Sildenafil produced reversible impairment of the rod and cone phototransduction in monkeys. Meanwhile, involvement of the postreceptoral retinal components was suggested. These findings contribute to the clarification of sildenafil-induced visual disturbances. It is suggested that the photoreceptors are predominantly, but not exclusively, affected in the retina of humans with sildenafil-induced visual disturbances.

show abstract

Digoxin-Induced Reversible Dysfunction of the Cone Photoreceptors in Monkeys

Cited by 12 publications

References 23 publications

N-Methyl-N-Nitrosourea–Induced Acute Alteration of Retinal Function and Morphology in Monkeys

N-Methyl-N-Nitrosourea–Induced Acute Alteration of Retinal Function and Morphology in Monkeys

Successful use of digoxin‐specific immune Fab in the treatment of severeNerium oleandertoxicosis in a dog

Sildenafil-Induced Reversible Impairment of Rod and Cone Phototransduction in Monkeys

Contact Info

Product

Resources

About