THE EFFECT OF EXPERIMENTAL UVEITIS ON THE UPTAKE OF PROSTAGLANDIN E₁ IN THE RABBIT IRIS‐CILIARY BODY

Abstract

Disruption of the blood-aqueous barrier in rabbits was elicited by infrared irradiation of the iris or by alpha-melanocyte stimulating hormone (alpha-MSH) given subcutaneously. One group of animals was pretreated with topical imidazole before the injection of alpha-MSH. The aqueous flare response was followed and the rabbits were killed at the expected height of the uveitis. The uptake of 3H-prostaglandin E1 in the iris with the ciliary body was then determined and found to be significantly decreased in the rabbits in which alpha-MSH had caused a severe damage of the blood-aqueous barrier. When alpha-MSH caused a more moderate aqueous flare response the prostaglandin uptake was on the contrary significantly increased. Pretreatment of the animals with topical imidazole enhanced parallelly the prostaglandin uptake and the aqueous flare response to alpha-MSH. Topical imidazole per se was found to increase the accumulation of prostaglandin. The prostaglandin uptake values were, however, unchanged in eyes in which infrared irradiation of the iris induced a moderate flare response.

The EFFECT OF POLYPHLORETIN PHOSPHATE ON THE AQUEOUS FLARE RESPONSE TO Α‐MELANOCYTE STIMULATING HORMONE

“…Assuming that PPP is a specific PG-antagonist (Eakins et al 1970) the present results support earlier studies indicating that PGs take part in the barrier damaging action of a-MSH, not via enhanced PG-synthesis (Bengtsson 1975) but possibly by pathologically increased PG accumulation in the iris and ciliary lhdy (Bengtsson & Ehinger 1977). On the other hand, it has not been proved at which cellular level PPP exerts its PG-antagonism in the eye.…”

“…However, imidazole administered topically instead of intraperitoneally strongly facilitated and potentiated the a-MSH response while there was no effect on PG mediated stimuli (Bengtsson 1976). In a recent study a-MSH was found effectively to increase the PG accumulating capacity of the iris-ciliary body (Bengtsson & Ehinger 1977). This study also indicated that topical imidazole facilitates and potentiates the protein leakage after a-MSH by further promoting the increase of PG accumulation caused by a-MSH.…”

“…The purpose of this study was to find out whether the damaging effects of a-MSH on the blood aqueous barrier are in some way dependent on PG-activity, though the a-MSH effects have been shown earlier to differ from PG-actions in many respects (Bengtsson 1975(Bengtsson , 1976Bengtsson & Ehinger 1977).…”

The Effects of Hormones on The eyes and Blurry Vision in Rabbits, Kittens, Rats, and Humans

“…It is uveitis that lowers prostaglandin uptake in the ciliary body of the rabbit iris. Imidazole and alpha-MSH also affect prostaglandin uptake (25). A study investigated the effects of injecting prostaglandins E1, E2, F1a, F2a, and A1 directly into the eye on the intraocular pressure (IOP) of rabbits that were under urethane anesthesia showed that except prostaglandin F1a, all prostaglandins studied caused a significant and lasting increase in intraocular pressure (IOP), often accompanied by miosis.…”