EFFECT OF CAVAL-PORTAL SHUNT ON OVARIAN TISSUE IN RATS .1. HISTOLOGICAL OBSERVATION

Forty-three female Sprague Dawley rats were divided into five groups, with groups 1-4 subjected to end-to-side caval-portal shunt (CPS). In addition to CPS, group 1 (n = 13), group 2 (n = 10), and group 3 (n = 7) rats had undergone removal of the right ovary and one-half of the l eft ovary, the left ovary, and one-half of the left ovary, respectivel y. Group 4 (n = 6) rats were not subjected to ovariectomy. Group 5 (n = 7) animals were not subjected to CPS but underwent left ovarian hemi resection. The ovarian volume of the hemiresected ovaries increased to 393.00 +/- 4.83 mm3 and 126.00 +/- 44.3 mm3 from 18.40 +/- 0.54 mm3 a nd 18.40 +/- 0.59 mm in groups 1 and 3, respectively, at the end of th ree postoperative months. The nonresected ovaries enlarged to 339.98 /- 5.09 mm3 and 226.3 +/- 46.2 mm3 from 36.79 +/- 1.09 mm3 in groups 2 and 3, respectively. When no ovaries were resected, the CPS animals i n group 4 showed an increment of ovarian volume of 1.75-2.2 times as m uch as the preoperative ones. In the animals that had undergone simple hemiovariectomy (group 5), the contralateral ovaries showed a signifi cant increase in volume (40.2 +/- 8.3 mm3 to 243.1 +/- 114.8 mm3) at 3 months. The hemiresected ovarian volume increased from 27.1 +/- 5.5 m m3 to 44.1 +/- 11.8 mm3. The histological sections of ovaries in group 1 showed early formation of theca-luteoma 3 months postoperatively, a nd there were demonstrable corpora atretica 6 months postoperatively. In the group 2 ovarian sections, there were multiple follicular cysts, and these cysts were lined by clusters of granulosa cells. There were nondisintegrated ova ejected from the cumulus oophorus in the ovarian sections from group 2 3 and 6 months postoperatively. In the group 3 ovaries, there were abundant theca-luteal cells in the sections. Promi nent granulosa-theca cell activity was present in the ovaries subjecte d to CPS. A similar observation was made in group 4, where more ovaria n mass was left in situ. Group 5 animals not subjected to CPS showed c ompensatory hyperplasia in the nonresected ovaries, and the hemiresect ed ovaries showed a slight enlargement. No typical granulosa-theca cel l tumors were formed in any of the groups of rats, indicating that gon adotrophin-estrogen imbalance could not be achieved as a result of the large quantity of the ovary remaining in situ.