Changes in some innate defence parameters of seabream (Sparus aurata L.) induced by retinol acetate

Tumouricidal activity of gilthead seabream (Sparus aurata L.) natural cytotoxic cells: the role played in vitro and in vivo by retinol acetate

“…The results showed how retinol acetate TUMORICIDAL ACTIVITY OF S. AURATA CYTOTOXIC CELLS enhances this innate activity in a dose-dependent manner although the positive e#ect is lost after 5 days. Higher injected amounts were lethal for the seabream [16], direct evidence that hypervitaminosis with vitamin A also has deleterious e#ects in fish. Adequate dosages of i.p.…”

“…For example, salmonids treated with vitamin A increased their resistance to infection [14,15], while gilthead seabream specimens fed high retinol acetate diets (the same as those used in this experiment) increased the leucocyte myeloperoxidase content and respiratory burst activity, e#ects which might be related to the antioxidant properties assigned to vitamin A [16].…”

“…In salmonids, vitamin A has been shown to increase disease resistance [14] or to decrease the mortality rate of Atlantic salmon after Aeromonas salmonicida injection although neither their humoural immune response nor phagocytosis were a#ected [15]. Cuesta et al [16] have previously described the e#ect of vitamin A (retinol acetate) on some gilthead seabream immune system responses. Dietary supplements of retinol acetate increased the leucocyte myeloperoxidase content and respiratory burst activity and it also produced mortality when administered by intraperitoneal (i.p.)…”

Leukocytes respiratory burst and lysozyme level in pacu (Piaractus mesopotamicus Holmberg, 1887)

“…Measurement of ROS production by phagocytes is of critical importance to investigate the physiological consequences resulting from cellular mechanisms that lead to the oxidative burst. In teleost fish, several methodologies can be used to measure ROS production during the respiratory burst such as chemiluminescence assay (Verlhac et al, 1996;Verlhac et al, 1998;Cuesta et al, 2002), reduction of ferricytochrome C (Jorgensen et al, 1993;Jeney et al, 1997;Santarém et al, 1997;Lee et al, 2004) and nitroblue tetrazolium (NBT) assay (Jeney and Anderson, 1993;Jeney et al, 1997;Castro et al, 1999;Cook et al, 2003;Sahoo et al, 2005). In this study, two such methodologies were selected to evaluate leukocyte burst oxidative in pacu: the chemiluminescence assay and NBT reduction assay.…”

“…When the outer cell wall of Gram-negative bacteria is disrupted due to the action of complement and other enzymes exposing the inner peptidoglycan layer of bacteria, then lysozyme becomes effective (Verlhac and Gabaudan, 1997). Lysozyme is measured by a turbidimetric assay based on the lysis of Gram positive bacteria, Micrococcus lysodeikticus, and this methodology is the most used in fish (Sankaran and Gurnani, 1972;Lie et al, 1989;Jorgensen et al, 1993;Verlhac et al, 1996;Jeney et al, 1997;Santarém et al, 1997;Verlhac et al, 1998;Cuesta et al, 2002;Balfry and Iwama, 2004).…”