Blood Pressure; Hypertension/complications; Kidney Diseases/prevention & control; Kidney/metabolism; Ovariectomy; Renin/metabolism; Aging/metabolism; Angiotensin I/metabolism; Angiotensin II/metabolism; Animals; Animals, Congenic; C-Reactive Protein/metabolism; Cell Adhesion Molecules/genetics; Cell Adhesion Molecules/metabolism; Disease Models, Animal; Female; Fibrosis; Hypertension/etiology; Hypertension/genetics; Hypertension/metabolism; Hypertension/physiopathology; Hypertrophy; Insulin-Like Growth Factor I/genetics; Insulin-Like Growth Factor I/metabolism; Intracellular Signaling Peptides and Proteins/genetics; Intracellular Signaling Peptides and Proteins/metabolism; Kidney/pathology; Kidney/physiopathology; Kidney Diseases/etiology; Kidney Diseases/metabolism; Kidney Diseases/physiopathology; Membrane Proteins/genetics; Membrane Proteins/metabolism; Peptide Fragments/metabolism; Proteinuria/etiology; Proteinuria/metabolism; Proteinuria/physiopathology; Proteinuria/prevention & control; RNA, Messenger/metabolism; Rats; Rats, Inbred Lew; Renin/genetics; Renin-Angiotensin System; Sodium Chloride, Dietary