EPITHELIAL SURFACE CHANGES AND INDUCTION OF GALLSTONES IN THE MALE SYRIAN-HAMSTER GALLBLADDER AS A RESULT OF A 2-MONTH SEX STEROID TREATMENT

Transmission (TEM) and scanning (SEM) electron microscopic observation s were correlated to characterize morphologic changes induced in the g allbladder of male Syrian hamsters following a two-month estradiol (E) and estradiol + medroxyprogesterone (E + MP) treatment. Compared to c ontrol (C), E-treated surface epithelial cells show pleomorphism, cyto plasmic vacuolizations, apical granules, excrescences and decapitation s, and small gallstone-like deposits. Following both E + MP treatment, a large accumulation of apical granules containing acidic mucoid prod ucts, abundant intraluminal deposits and numerous fields of observatio n suggest that cell debris and mucous condensation could participate i n the formation of the large intraluminal gallstone-like deposits dete cted as a result of this treatment. In control gallbladders these even ts were never observed. MP added to E also increases liver and gallbla dder weight as well as blood lipid levels. These findings complement a nd confirm other previous data obtained following short steroid treatm ent in male, ovariectomized and intact female hamsters. In addition, t hese results support our hypothesis that gallstone nucleation and grow th originate from multiple factors, hormonal disturbance, modulation o f liver lipid metabolism, production of cell debris and mucus, can be responsible for the initial gallstone nucleation.