[Is it possible to obtain a reduction of body weight exclusively via a loss in fat mass? Experience with d-fenfluramine]. / E possibile ottenere la riduzione del peso corporeo esclusivamente attraverso una perdita di massa adiposa? Esperienze con d-fenfluramina.

Aim of the study was to observe if the administration of an anorectic drug, d-fenfluramine, in addition to hypocaloric diet, could influence the body composition and adipose mass distribution during a weight decrease programme in 17 obese women. Drug's effects plus diet on body weight changes were compared with those of a "only-diet programme" in another group of 18 obese subjects, sex and age matched. Both groups were observed for a 6-month period. All subjects were selected on the base of Index Body Weight % within 120-200 and without any therapy for other diseases. Blood samples were drawn before, during (3rd month) and after the period of observation for the measurement of OGTT, serum lipids, liver and kidney function parameters, blood cells count. Body weight and height, body composition, waist-to-hip ratio were also evaluated. Results documented: 1) significant reduction of body weight in the group kept on the combined therapy; 2) significant variation of body composition with increment of fat free mass and adipose mass decrease; 3) significant improvement of glucose tolerance, liver and kidney function parameters. In conclusion, our data show beneficial effects of d-fenfluramine on appetite reduction, influencing the carbohydrates assumption and the consequent fat mass loss with a good tolerability of the drug.

Block of the cardiac pacemaker current (If) in the rabbit sino-atrial node and in canine Purkinje fibres by 9-amino-1,2,3,4-tetrahydroacridine.

We have investigated the action of 9-amino-1, 2, 3, 4-tetrahydroacridine (THA) on the pacemaker current If in rabbit sino-atrial node myocytes and in canine Purkinje fibers. THA at concentrations in the range 3-300 microM blocked If in a voltage-independent manner, as revealed by measurements on the fully activated I/V relation for If. The dose/response relationship of the If maximal slope conductance (Gf) can be fitted by assuming a cooperative binding reaction where two THA molecules are required to block one If channel. Half-maximal block occurred at 18.2 microM in the sino-atrial node and 36.6 microM in Purkinje fibers. THA also affected the If kinetic properties. This was examined in the sino-atrial node where the current activation curve was shifted in the negative direction on the voltage axis (- 21 mV at 30 microM THA). The delayed rectifier current, IK, was also reduced by THA in sino-atrial node myocytes: at - 40 mV the IK fully activated value was decreased to 37% of its control value by 30 microM THA, with only a minor modification of the position of the activation curve at the same potential. Thus, although THA blocks If at a lower concentration than other known If-channel blockers [DiFrancesco (1982) J Physiol (Lond) 329:485-507], its action on the pacemaker current is not specific.