RABBIT CILIARY PROCESS RESPONSES TO DIFFERENT ROUTES OF WATER-SOLUBLEMARIJUANA-DERIVED MATERIAL ADMINISTRATION

The pharmacologic and morphologic effects of water-soluble marihuana-d erived material (MDM) were examined in rabbits after different routes of administration. Subcutaneous (SC) MDM alone caused little change in intraocular pressure (IOP) yet significantly antagonized subsequent i ntravenous (IV) or intravitreal (IVT) MDM injections; this occurred de spite the failure of SC MDM alone to induce morphological changes in t he ciliary processes. Morphologic effects are usually associated with a pharmacologic response. IV MDM alone induced a large IOP fall that a ccompanied substantial morphologic changes; further IV MDM was ineffec tive in causing a change in IOP until 4 or 5 days after the initial in jection. IVT MDM after IV MDM caused a fall in IOP with additional mor phologic effects. IVT MDM alone caused marked pharmacologic and morpho logic changes, and IV MDM after IVT MDM caused additional morphologic changes that accompanied an IOP fall. IVT injections, after a prior IV T injection, were pharmacologically and morphologically potentiated. M DM injection at an initial site influenced a subsequent MDM injection at the same or another site, either by antagonism or potentiation of t he pharmacologic and morphologic response to the second injection. The quantitative impact of a second injection, regardless of its route of administration, was related to the time after the first injection. MD M offers an interesting model for the study of drug interactions when given by different routes of administration as well as a model for an inflammatory agent.