Site - dependent effects of ions on µ - , "d" - and k - opioid binding in suspensions of guinea - pig brain membranes Two different copies of Linda E Robson, Stewart J Paterson and Hans W Kosterlitz, 'Site - dependent effects of ions on µ - , "d" - and k - opioid binding in suspensions of guinea - pig brain membranes' reprinted from J W Holaday, P - Y Law and A Herz, eds., 'Progress in Opioid Research (Proceedings of the 1986 International Narcotics Research Conference); NIDA [National Institute on Drug Abuse] Research Monograph 75' (Washington D C, 1986), 61 - 63. 1986