[Effects of drugs on the upper urinary tract of the human]

The effects and the possible mode of action of some drugs were studied in isolated preparations of the human upper urinary tract. Norepinephrine, histamine and serotonin had excitatory effects, whereas isoprenaline had inhibitory effects on smooth muscle activity. Norepinephrine induced different types of mechanical activity in different tissues of the human upper urinary tract suggesting different and separate coupling mechanism between the receptors involved and the calcium pools responsible for initiation of contraction. Acetylcholine had only little effects on smooth muscle activity even in high concentrations. Contractions which were triggered by action potentials or depolarizing extracellular potassium concentrations were highly sensitive to calcium channel blockers. Other drugs with relaxing properties such as papaverine, bencyclane, flavoxate or pitofenone seem to have effects on different calcium activation or calcium storing mechanisms.