Spinal cord injury (SCI) at Thl3 was induced in female Wistar rats, and changes in the urinary bladder were examined during the acute phase of SCI. Wet weights of the spinal bladders increased twofold over controls by 7 days after SCI. Intravesical volumes increased sixfold over control values by day 3, and then decreased 7 days after the injury. Maximal pressure within the bladder decreased in all spinal rats compared with controls. Smooth muscle cells were isolated from the urinary bladder, and their total protein and DNA content were measured by multiparametric cytofluorometry. DNA content of isolated smooth muscle cells decreased by day 3 and remained 7 days after the spinal injury. Total protein content of isolated smooth muscle cells was decreased 1 day after and increased 7 days after the spinal injury, just when spinal reflex of the bladder recovered. These findings suggest that hypertrophy of smooth muscle cells in urinary bladder is related to the activity of peripheral autonomic nerve and that smooth muscle cells already begin to hypertrophy during the spinal shock period to adjust themselves to the new state, that is, the spinal bladder.

A possible mechanism is presented by which reduced glutathione (GSH) regulates prostaglandin (PG) synthesis in microsomes of the porcine bladder epithelium. At a concentration of GSH less than 10(-5) M, microsomes produced more PGI2 and PGF2 alpha than PGE2. At a greater GSH concentration, PGE2 synthesis was remarkably enhanced. On the other hand, PGI2 and PGF2 alpha synthesis was inhibited. In the presence of 10(-3) M GSH, ten times more PGE2 was produced than the other PGs. The concentration of GSH in porcine bladder epithelium was about 0.6 mM. This reciprocal effect of GSH was also observed in rabbit and bovine bladder epithelium. These findings suggest that GSH is involved in the regulation of PG synthesis in urinary bladder epithelium. GSH may influence the physiological and pathophysiological changes elicited by PGs in the lower urinary tract.

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Membrane fluidity and lipid composition of rat testis in experimental bilateral cryptorchidism were studied. Membrane fluidity measured by fluorescence anisotropy of diphenylhexatriene decreased on the 3rd day of intraabdominal fixation, at an early stage of cryptorchidism. Lipid composition of testicular membrane was changed drastically by the treatment, and time-dependent changes were observed during the course of the experiment. Cholesterol content increased significantly, but phospholipid content was not affected by the treatment. The ratio of cholesterol to phospholipids increased significantly. Fatty acid moieties of phospholipids varied during the course of the experiment. The ratio of unsaturated to saturated fatty acids decreased on the 3rd day. These changes indicated a different physical state of cryptorchid membranes from normals, and the changes may be involved in the pathophysiology of cryptorchidism.

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