Biodistribution studies of bee venom and spider toxin using radiotracers

The use of radiotracers allows the understanding of the bioavailability process, biodistribution, and kinetics of any molecule labelled with an isotope, which does not alter the molecule's biological properties. In this work, technetium-99m and iodine-125 were chosen as radiotracers for biodistribution studies in mice using bee (Apis mellifera) venom and a toxin (PnTX2-6) from the Brazilian "armed" spider (Phoneutria nigriventer) venom. Incorporated radioactivity was measured in the blood, brain, heart, lung, liver, kidney, adrenal gland, spleen, stomach, testicle, intestine, muscle, and thyroid gland. Results provided the blood kinetic parameter, and different organs distribution rates.(AU)

Striatal dopamine receptor supersensitivity afte long-term haloperiodol treatment of hypophysectomized rats

Dopamine (DA) receptor sensitivity was studied after long-term treatment with haloperidol (0.5 ad 3.0 mg/Kg, ip, single daily dose) or saline in hypophysectomized and infact rats. Haloperidol treatment for seven days produced a 25 to 125% increase in [3H]-spiroperidol binding to strial DA receptors in a dose-dependent fashion. The increase in binding sits (Bmax) was ximilar in both hypophysectomized and intact rats when compared to controls. The present results show that haloperidol treatment