Some physiological effects of M99 etorphine
on immobilized free-ranging moose.
It became apparent that agonists such as morphine, antagonists such as naloxone and mixed agonist-antagonists such as nalorphine must act on multiple receptors and this was confirmed in the early 1970s with (3) H-labeled levorphanol (2), naloxone (3), etorphine (4) and dihydromorphine (5) that bound specifically to sites in the central nervous system.
Stereospecific binding of the potent narcotic analgesic [3H] etorphine to rat-brain homogenate.
Metabolic and hormonal responses to neuroleptanalegesia (etorphine
and acepromazine) in the horse.
After trying several drugs over an extended period, they found the ideal one--a synthesised version of morphine called M99 or etorphine
The method utilizes etorphine as the internal calibrator, conversion of the analytes to the pentafluoropropionyl esters, and chromatography on a packed column.
The method was optimized by using N-n-propylnorbuprenorphine, a closer structural analog of buprenorphine than the etorphine used by Cone et al.
Different immobilizing agents were used over the years (Table 1); the narcotics etorphine
and carfentanil (Lanthier et al., 1999) were replaced, first with medetomidine-zolazepam-tiletamine (MZT), then with medetomidine-ketamine (MK) (R.E.A.
Recommended doses are carfentanil at 0.01 mg/kg or etorphine
at 7.5 mg/adult.
The animals were immobilized with an intramuscular injection of etorphine
HC1 that was reversed with diprenorphine HO, as described by Griffiths et al.
We examined to what extent winter chemical immobilization using etorphine
and subsequent handling affected the immediate risk of mortality and subsequent calving success and early calf mortality in a Norwegian moose population.
Adult female moose were immobilised with etorphine
and xylazine (Sandegren et al.