Serum retinoids in retinitis pigmentosa patients treated with vitamin A.

Abstract

BACKGROUND:

Patients with retinitis pigmentosa have been suggested to benefit from treatment with moderate doses of retinyl palmitate. Retinyl palmitate is not an active retinoid in itself but is metabolised to active components in the body. To find out which metabolites of retinyl palmitate were formed and at which concentrations, we measured the concentrations of retinol, retinyl palmitate, retinoic acids and tocopherol in serum of patients treated with oral retinyl palmitate for retinitis pigmentosa.

METHODS:

Nine male patients and one female diagnosed as having retinitis pigmentosa after a complete ophthalmological examination including a full-field electroretinogram were given vitamin A at their own request as one daily morning dose of 16600 IU vitamin A. Blood samples were obtained before and after > 2 weeks of treatment. The concentrations of retinoids and tocopherol were measured with established methods.

RESULTS:

The patients were not deficient in vitamin A or vitamin E as judged from the serum vitamin concentrations. Treatment with retinyl palmitate significantly increased the serum concentration of retinyl palmitate and of 13-cis-retinoic acid but not of retinol, tocopherol or all-trans-retinoic acid.

CONCLUSIONS:

Neither retinyl palmitate nor 13-cis-retinoic acid, are known to be biologically active. However, 13-cis-retinoic acid can isomerise to the active vitamin A derivative, all-trans-retinoic acid. It is suggested that patients may be treated with a small dose of 13-cis-retinoic acid instead, to avoid the relatively long metabolic detour from retinyl palmitate.

• Authors: G A Fex, S Andréasson, B Ehinger
• Journal: Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie (Graefes Arch Clin Exp Ophthalmol) Vol. 234 Suppl 1 Pg. S18-21 (Aug 1996) ISSN: 0721-832X [Print] Germany
• PMID: 8871145 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anticarcinogenic Agents
• Diterpenes
• Retinoids
• Retinyl Esters
• Vitamin A
• Vitamin E
• retinol palmitate
• 4-oxoretinoic acid
• Tretinoin

Topics

• Administration, Oral
• Adult
• Aged
• Anticarcinogenic Agents (blood)
• Chromatography, High Pressure Liquid
• Diterpenes
• Electroretinography
• Female
• Humans
• Male
• Middle Aged
• Retinitis Pigmentosa (blood, drug therapy, physiopathology)
• Retinoids (blood)
• Retinyl Esters
• Tretinoin (analogs & derivatives, blood)
• Vitamin A (analogs & derivatives, blood, therapeutic use)
• Vitamin E (blood)