PARENT SESSION
MALE REPRODUCTIVE TRACT

Monday, August 2, 2004
10:30 AM–12:30 PM
Buchanan Courtyard

(169) EFFECTS OF THE ANTIESTROGEN ICI 182,780 ON THE REPRODUCTIVE TRACT OF THE ADULT MALE HAMSTER.

Carnes, Kay¹, Ford, James¹, Hess, Rex ¹, ¹ University of Illinois Urbana-Champaign, Urbana, Il

ABSTRACT- The antiestrogen ICI 182,780 inhibits efferent ductule function, producing a build up of luminal fluid and subsequent effects on the epithelium and epididymal sperm maturation. However, it is not clear that such responses are consistent across species, as differences in response were noted between the rat and mouse. We are beginning studies to determine the effects ICI 182,780 in adult males of several species. Here we present data from the Golden Syrian Hamster, a seasonal breeding rodent which differs from the rat and mouse by having a rete testis/efferent duct junction located at the apex of the testis. Male Golden Syrian hamsters, 70 days of age, were housed under a photo-stimulatory diurnal light cycle (16 hr light; 8 hr dark). Weekly injections of ICI 182,780 were given subcutaneously at dosages of 50 mg/kg/week for 15 days or 200 mg/kg/wk for 30 days. Controls received the same volume of castor oil. Computer-assisted sperm analysis (CASA) and radioimmunoassay for testosterone were performed on the 200 mg/kg/week group. Light microscopy revealed mild dilation of the efferent ductule lumen at the 50 mg/kg ICI dosage and severe dilation of the ductules at the 200 mg/kg dosage animals, compared to the controls. Immunohistochemical staining for sodium hydrogen exchanger 3 and androgen receptor (AR) showed no difference between the controls and the ICI treated animals at either dosage. Estrogen receptor-alpha (ERa) staining showed no difference between controls and the low dosage, but ERa staining was reduced in the 200 mg/kg dosage. CASA analysis showed that there was no difference with regard to testis weight and sperm motility when comparing treated and controls. However, sperm concentration was significantly (p<0.05) higher in the high dose treated animals vs controls. Testosterone was higher in the treated animals but not significant statistically. The reduction of ERa expression in the hamster is similar to the rat, where a decrease on day 7 was observed and significant decreases starting on day 45 of treatment. AR was not affected in the rat or hamster. Further studies are required in the hamster to determine if an increase in testosterone is significant, as is seen in the mouse, and whether or not the increased sperm concentration in the treated hamsters is due to an interaction between testosterone and estrogen actions.

KEY WORDS: Efferent ductule, Estrogen receptor alpha, Antiestrogen, Testosterone