The effect of ammonium chloride concentrationson the content of carotenoid pigments in the body of Lymnaea stagnalis

The paper deals with the peculiarities of distribution of β-carotene and xanthophylls in the body of Lymnaea stagnalis (Linnaeus, 1758) (Pulmonata, Lymnaeidae) in the normal conditions and under the action of different concentrations of NH4Cl, depending on duration of exposure (2, 7, 14 and 21 days). L. stagnalis (300 copies) were collected in September 2013–2014 (in Zhytomyr region). Toxicant NH4Cl was used in concentrations corresponding to 0.5, 2, 5 and 10 MAC. The content of β-carotene and xanthophylls was determined by the Taylor method. 2400 biochemical analyses were carried out. The article shows that under the action of 0.5 MPC NH4Cl adaptive processes are stimulated in the body of L. stagnalis and total antioxidant activity is activated, as evidenced by changes in the content of β-carotene and xanthophylls in the organs (hepatopancreas, pallium and foot) and tissues (hemolymph) of the mollusks under study. The research proves that the action of concentration discussed above during 2, 14 and 21 days causes the increase in the content of β-carotene in hepatopancreas (1.63–5.73 times), pallium (1.68–5.37 times) and foot (1.81–3.89 times) of animals. Incubation of mollusks in solutions of NH4Cl (0.5 MAC) for 7 days resulted in the decrease of figures in these organs by 23,6–38,8% relatively to control. It should be noted that from the overall dynamics hemolymph is somewhat distracting; for it 1.35–1.46 times’ decrease in the content of β-carotene after short-term action of the toxicant (2 and 7 days) and β-carotene increase by 2.79–7.38 times under conditions of prolonged exposure (14 and 21 days) is recorded. The content of xanthophylls correlates with the content of β-carotene on the 2nd, 7th and 14th day of toxic action, but by increasing the time of contact with toxic substances to 21 days the decrease in figures by 20,9–40,7% in foot and pallium is recorded. When the toxicant concentration is increased to 2 MAC (with 2 days’ exposition) β-carotene content grows 2,08–5.98 times throughout the body of L. stagnalis and xanthophyll content decreases in hepatopancreas, pallium and foot (by 51,8–67,3%). When increasing duration of exposure in solutions of this concentration to 7, 14 and 21 days the decrease is recorded in both parameters studied: β-carotene (by 52.1–73,8% in hepatopancreas, by 31,7–69,0% in pallium, by 56,1–80,6% in foot) and xanthophylls (by 44,6–82,6% in hepatopancreas, by 51,6–68,2% in pallium, 75,6–83,8% in foot). Increase in the toxicant concentration to 5 and 10 MAC regardless of the length of the exposure leads to reduction of the content of animals’ β-carotene in hemolymph (by 39,9 – of 92.6%) and hepatopancreas (11,2– 95,7%). In the mollusk foot the decrease of figures under action of 5 and 10 MAC of the toxicant during 7, 14 and 21 days (by 33,2–94,8% relative to control) irrespective of the exposure duration is recorded. Long stay (14 and 21 days) in solutions of the toxicant at the concentration of 5 and 10 MAC causes the reduction of xanthophyll content throughout the body of L. stagnalis. Tissue-specific distribution of β-carotene and xanthophylls in the tissues (organs) of L. stagnalis is shown. Hemolymph is characterized by minimum content of investigated pigments, and maximum values vary between organs (tissues) depending on the concentration and duration of exposure of animals to the toxic solution.