Reduced cholecystokinin in the brain of LEC rats with hepatic encephalopathy

Decreased numbers of cholecystokinin-immunoreactive nerve cells in the cerebral cortex of LEC rats with a hereditary hepatitis

The distribution of CCK-immunoreactive cells was investigated by the indirect fluorescence method in the cerebral cortex of LEC (Long-Evans Cinnamon) rats which have recently been introduced as a model of jaundice and hepatic encephalopathy. Reduction of CCK-immunoreactive nerve cells was observed in the brains of LEC rats with stage III to V hepatic encephalopathy in comparison with the rats without hepatic encephalopathy. These observations were confirmed by counting the CCK-positive nerve cells at magnification x 125. 3 microscopic fields per animal were immunostained and CCK-immunoreactive nerve cells counted. The number of CCK-immunoreactive cells per field was 28.5 +/- 0.7 (mean +/- SEM, n = 5) in rats without hepatic encephalopathy, and 14.1 +/- 2.0 (n = 3) in rats with stage III to V hepatic encephalopathy. Thus, the number of CCK-immunoreactive nerve cells was significantly less in rats with stage III to V hepatic encephalopathy (p less than 0.05). A decrease in CCK-immunoreactive nerve cells was not observed in the rats with stage I or II hepatic encephalopathy. This study shows that there is a relationship between the severity of hepatic encephalopathy and the number of CCK-immunoreactive nerve cells in the cerebral cortex.

Reduced somatostatin-like immunoreactivity in the brain of LEC rats with hepatic encephalopathy

Somatostatin-14-like immunoreactivity (S14LI) and somatostatin-28(1-12)-like immunoreactivity (S28(1-12)LI) in the brain of LEC (Long Evans Cinnamon) rats with hepatic encephalopathy were measured. Significant reduction of both S14LI and S28(1-12)LI was observed in the hypothalamus, medulla oblongata, striatum and spinal cord. Both of the immunoreactivities in the hypothalamus of these rats were approx. 50% of those in LEC rats without hepatic encephalopathy. The amounts of reduction of S14LI significantly correlated with those of reduction of S28(1-12)LI. No significant difference in gel chromatographic profiles of S14LI and S28(1-12)LI was observed between LEC rats with and without hepatic encephalopathy. These results suggest that the reduction of somatostatin-like immunoreactivity in LEC rats with hepatic encephalopathy may be caused by a decrease in production of prosomatostatin rather than altered degradation.