Introduction: Calcitonin (CT) regulates blood calcium (Ca+2) levels in mammals, but the results of experiments on its role in fish are uncertain, its functions exceeded the limits of regulation of Ca+2.
Aim: This experience represents a trial to remove that ambiguity and determine role of calcitonin by clarifying its relationship with different biochemistry parameters. Therefore, we investigate the effect of (CT) on some biochemical parameters of blood in female fish Poecilia latipinna, these are Ca+2, urea, creatinine, alkaline phosphatase enzyme (ALP), follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The study also deals with the follow up of histological changes that are caused by (CT) in the liver, kidney, and intestines of the fish.
Material and Methods: The fish were brought from ornamental fish shops and were adapted and reared in the laboratory. The sample of fish was divided into two groups; The first group was injected with 4 microliters of (CT) for ten consecutive days. At the end of the experiment, blood was drawn from the fish and then it anatomized and tissue sections of organs under study were prepared.
Result: The finding show calcitonin works to reduce level of Ca+2 in the blood with a significant difference (0.03) at the probability level P ≤ 0.05. And was not affected urea and creatinine by the hormone, while the level of ALP enzyme increased with a significant difference (0.04) at the probability level P ≤ 0.05. With sex hormones, the effect was limited to LH without FSH. LH levels increased significantly with (0.02) at P ≤ 0.05. CT caused histological changes in the kidney and intestines, while the liver was not affected by (CT).
Conclusion: Calcitonin has been shown to play a role in Ca+2 regulation in fish blood and its work overlaps with different organs of the fish body.