  In this paper we provide an extension to the Jellett-Minkowski's formula for
immersed submanifolds into ambient manifolds which possesses a pole and radial
curvatures bounded from above or below by the radial sectional curvatures of a
rotationally symmetric model space. Using this Jellett-Minkowski's generalized
formula we can focus on several isoperimetric problems. More precisely, on
lower bounds for isoperimetric quotients of any precompact domain with smooth
boundary, or on the isoperimetric profile of the submanifold and its modified
volume. In the particular case of a model space with strictly decreasing radial
curvatures, an Aleksandrov type theorem is provided.
