advertisement
Abstract #5629 Published in IGR 2-1
The effect of elevated progesterone levels on intraocular pressure in lions (Panthera leo)
Ofri R; Shore LS; Kass PH; Horowitz IHResearch in Veterinary Science 1999; 67:121-123
Recently, the authors reported that intraocular pressure (IOP) in juvenile male lions (Panthera leo) is significantly higher than in juvenile lionesses. Whilst they could not ascertain the basis for this gender-related difference, they suspected that it was the result of fluctuations in levels of sex hormones. Because 19 of the 22 lions described in their previous report had to be re-anaesthetized, the authors repeated tonometry in these animals, to try and correlate between IOP and the levels of progesterone, oestrogen and/or testosterone. Based on elevated (>5 ng ml-1) levels of progesterone, lionesses were divided into a luteal (n=8) and a non-luteal (n=13) group. In the luteal group, mean IOP was 27.07±2.15 mmHg, significantly (p=0.001) higher than in the non-luteal group (21.61±2.70 mmHg). Oestrogen, testosterone, anesthesia, and age had no significant effect on IOP. It is suggested that elevated progesterone levels associated with the luteal phase in lionesses cause increased resistance to aqueous humor outflow, leading to IOP elevation. Similar ocular hypertension has been observed in rabbits following exogenous progesterone application, but this is the first report on the hypertensive effect of endogenous progesterone on IOP.
Dr. R. Ofri, Koret School of Veterinary Medicine, Hebrew University of Jerusalem, PO Box 12, Rehovot, 76100, Israel ofri@agri.huji.ac.il
Classification:
5 Experimental glaucoma; animal models
9.4.15 Glaucoma in relation to systemic disease (Part of: 9 Clinical forms of glaucomas > 9.4 Glaucomas associated with other ocular and systemic disorders)