Progesterone fate in rabbit cornea.

Area of Science:

• Ophthalmology
• Endocrinology
• Biochemistry

Background:

• Progesterone plays a role in various physiological processes.
• Understanding steroid metabolism in ocular tissues is crucial for ophthalmology.

Purpose of the Study:

• To investigate the metabolic fate of progesterone in excised rabbit corneas.
• To identify progesterone metabolites and the enzymes involved in corneal tissue.

Main Methods:

• Excised adult New Zealand rabbit corneas were incubated with progesterone-4-14C for 96 hours.
• Metabolites were isolated and identified using paper chromatography at 24-hour intervals.
• Enzyme activity was inferred from the identified metabolites.

Main Results:

• 20 alpha-Hydroxy-pregnen-3-one was the predominant progesterone metabolite, showing a linear increase over 96 hours.
• Other identified metabolites included 20-hydroxy-4-pregnen-3-one, 5 alpha-pregnane-3,20-dione, 5 beta-pregnane-3,20-dione, and 6 beta-hydroxy-4-pregnen-3,20-dione.
• Enzyme systems such as 20 alpha/beta-reductase, 5 alpha/beta-reductase, and 6 beta-hydroxylase were implicated in corneal progesterone metabolism.

Conclusions:

• The rabbit cornea possesses enzymatic pathways for progesterone metabolism.
• Specific reductase and hydroxylase enzymes are active in the cornea, converting progesterone into various metabolites.
• No evidence of fungal or bacterial contamination influencing the metabolic profile was found.