Studies on pituitary [TSH]-thyroid [T3, T4, FT4]-liver axis during seasonal variation at two different ages of male camel [camelus dromedarius]

ABSTRACT

This study was undertaken to investigate the intricate relationship between pituitary, thyroid and liver of male camel. Thyroids and corresponding livers and blood at two ages during breeding and non-breeding seasons were collected from slaughter houses. Tissues were used for histological examination and evaluation of T3 and T4 content. Serum was used for determination of TSR, T3, T4 and FT4. Some fat and protein profiles were estimated. Serum activity of certain enzymes as ALT, AST, LDH, and ALP were also measured. The data showed that most of the thyroid follicles were large in old non-breeding and were small in young and old breeding animals. Mild to moderate fatty infiltration and small to medium sized lipid inclusions were common feature in hepatocytes of all tested animals especially in old age. TSFI and T3 in old non-breeding were significantly decreased than old breeding. No significant variation between the different seasons and ages concerning FT4 while a significant decrease in serum T4 was observed in old non-breeding than young breeding camel. No significant variation in the amount of T3 and T4 in the liver extracts while thyroid extract obtained from camel in the non-breeding season showed a significant increased in T4 at both ages than breeding season at any age. Old camel had a significant increased in serum triglyceride, total lipids and cholesterol than young. No significant variation between the two different seasons and ages concerning total protein, albumin, globulin, albumin globulin ratio, ALP and LDH. In the breeding season, level of serum AST was significantly higher in old than young camel, while, old camel during non-breeding season showed a significant increase in serum ALT than young at any season. It is clearly that the old camel during the non-breeding season [summer], their physiological activities concerning pituitary [TSH], thyroid hormones [T3 and T4] and liver function parameters [fat metabolism, ALT and AST] were negatively affected