Responses of the prolactin cells of the stinging catfish Heteropneustes fossilis following lead intoxication

The present study investigated the effects of lead nitrate on the histo-cytological changes in prolactin cells of Heteropneustes fossilis. Catfish were subjected to 657.6 and 164.4 mg/L of lead nitrate for 96 h and 28 days, respectively. Blood from fish was collected on 24, 48, 72 and 96 h in the short-term and after 7, 14, 21, and 28 days in the long-term experiments. Blood was collected for analysis of calcium levels and pituitaries were fixed for histological studies. After short-term lead exposure, plasma calcium levels of fish remain unaffected at 24 h. The levels exhibit a decrease after 48 h which persists till end of the experiment (96 h). Plasma calcium levels of fish exposed to lead for 7 days exhibit a decrease. This decrease persists progressively till the end of the experiment (28 days).Prolactin cells of the fish exposed to lead remain unaltered throughout the short-term experiment. Whereas in chronically exposed fish the prolactin cells remain unaffected till day 7. Nuclear volume of these cells exhibits an increase and cells are noticed degranulating after 14 days of lead treatment. These changes are more pronounced 21 days onward. Also, after 28 days degeneration among prolactin cells is observed.