Submission Number: WAI-4-10-6

Abstract Number: 287

GALACTOSEMIA AND RAT GRANULOSA CELL APOPTOSIS.

KW Lai ¹, L Cheng ², Benjamin K Tsang* ³ and WS O* ¹

Dept. of Anatomy, Univ. of Hong Kong ¹
Dept. of Biochemistry, Univ. of Hong Kong ²
Dept. of Obstetrics & Gynaecology and Cellular & Molecular Medicine, Univ. of Ottawa and Loeb Health Research Institute, Ottawa, Canada ³

Abstract:
Galactosemia is a genetic disease with deficiency of galactose-1-uridyltransferase resulting in the accumulation of galactose or galactose-1-phosphate in blood and tissues. Clinical consequences include mental retardation, visual cataract and ovarian failure. We postulate that a change in the molecular mechanism controlling apoptosis may be involved in the decreased ovulation and fertility of galactosemic females. A rat model was developed to study the molecular mechanism involved in ovarian failure associated with galactosemia. 3-4 weeks old female Sprague-Dawley rats (8 per group) were fed with normal or with 50% galactose diet (galactosemic group) for 4 weeks. Both groups were induced to ovulate on Day 3 of the oestrous cycle with eCG (50IU/100g body weight) and hCG (50IU/100g) 48 h thereafter. Rats were killed 18 h post-hCG by sodium pentobarbitone overdose. Blood galactose levels (p<0.001), kidney and liver (p<0.001), uterine and ovarian (p<0.05) weights were significantly different between galactosemic and control groups. The ovaries were fixed in neutral buffered formalin for morphometric analysis. Ovulated oocytes flushed from the oviducts showed that the number of ovulation in galactosemic rats was significantly lower than that of the control (5.1 1.9 vs 18.6 5.2; mean s.e.m.; p<0.001). When rats were killed at different time points after hCG injection to assess granulosa cell apoptosis and Fas/Fas ligand (FasL) expression by in situ TUNEL and Western blot, respectively, Fas and FasL contents and apoptosis were significantly higher in the galactosemic group than controls. These findings support our hypothesis that ovarian dyfunction in galactosemic subjects is due to increased apoptosis in granulosa cells of maturing follicles [Supported by a grant from HKU (7289/98M)]. .

Keywords: galactosemia, granulosa cell, apoptosis

This abstract is being presented at: 8:00 AM in session:
Follicular Development II