“…In these condtions, a 4-fold increase in the smooth muscle cell number was demonstrated. Further analysis confirmed the persistence of the proliferative capacity of the adult's smooth muscle in the ureter of other species as a consequence of an obstruction [Gee and Kiviat, 1975] and, recently, as a conSmooth Muscle Cell Hypertrophy and Hyperplasia in the Partially Obstructed Gut of the Rat: A Quantitative Evaluation sequence of systemic treatment with epidermal growth factor [Vinter-Jensen et al, 1997]. In addition, the capacity for cell proliferation in the smooth muscle has been assessed in other organs under particular experimental and/or pathological conditions, such as vessels of hypertensive rats [Owens and Reidy, 1985;Owens, 1985Owens, , 1989, myometrium during treatment with estrogen [Martin et al, 1973], airway smooth muscle underlying bronchial asthma [Page and Coyle, 1989;Ebina et al, 1993], smooth muscle at various levels of the gastroenteric system, after resection [Jurukova and Atanassova, 1974;Nguyen et al, 1996] and after partial obstruction [Gabella, 1975[Gabella, , 1979[Gabella, , 1990Brossa et al, 1992a, Canavese et al, 1992.…”