Vitamin C deficiency in the catfishClarias gariepinus

Abstract

Regardless of the absence of spinal deformities, vitamin C deprivation in adult-sized Clarias gariepinus challenged the physical integrity and survival of ®sh, inducing changes that greatly resembled those of ®ngerlings of other species. Vitamin C was presumed to be a dietary facilitator, which when deprived in the diet of C. gariepinus, would obstruct intestinal absorption of iron and/or impair its release from the reticulo-endothelial stores. This impaired erythrocyte synthesis led into anaemia (as indicated by lowered levels of red blood cells, haemoglobin and haematocrit). Leukopenia noted in ®sh on a scorbutic (lacking vitamin C) diet suggested functional depression of phagocytic engulfment with increased susceptibility to the deteriorating action of pathogenic agents. Changes in histology included hypertrophy, oedematous separation and telangiectasia of gill lamellae. Shrunken glomeruli, sloughed Bowman's capsules and tubular dilation and distortion were also shown. Shrunken hepatocytes and the occurrence of yellowish ceroid pigments were the concrete histopathological signs in liver. Vitamin C is thus suggested as a potent antioxidant that oers protection against oxidative damage to various ®sh tissues. KEY KEY WORDS

Haemato-biochemical disorders associated with nodavirus like-agent in adult leaping mullet Liza saliens (Risso, 1810) in the Caspian Sea

“…Unlikely, the reduction of leukocytes and lymphocytes as well as the increase of neutrophils and myelocyts were seen in long time starvation [45,46]. Vitamin C and amino acids have important roles on regulation of innate and adaptive immunity [1,18]. Thus, it seems that the long time malnutrition disturbed the haemopoiesis of these cells and caused incompetency of the fish immunity in the infected group.…”

Effects of Vitamin C and E Administration on Leukocyte Counts in Rainbow Trout (Oncorhynchus mykiss)

“…Safarpour-Amlashi et al reported higher lymphocytes in Beluga (Huso huso) fed with the high levels of vitamin E (400 mg/kg diet) for 8 weeks [37]. It has also shown a significant increase of lymphocytes in fish fed vitamin C at an elevated dose for longer periods [20,38]. In contrast to our findings, Menezes et al pointed out that vitamin E supplemented in fish diet reduces the number of total thrombocytes, lymphocytes and neutrophils, and increases eosinophils [39].…”

“…Furthermore, they are important antioxidants offering protection against oxidative damages [20], enhancing the resistance of red blood cell membranes [18,[21][22][23][24], protecting leukocyte functions [5,18,20,25,26], and influencing blood cell indices such as leukocytes profile [24,27].…”

Efeito da vitamina C sobre os parâmetros hematológicos de kinguio (Carassius auratus)

“…No processo metabólico a vitamina C auxilia na maturação dos eritrócitos, na coagulação sanguínea e na manutenção da hemoglobina em níveis normais, apesar de ainda não ser conhecida a dosagem ideal para cada espécie. Adham et al (2000), constataram uma redução do hematócrito, da hemoglobina e da contagem de eritrócitos em animais que não receberam suplementação vitamínica de ácido ascórbico, caracterizando como anemia.…”

“…O menor nível de hemoglobina, mesmo que não diferindo estatisticamente, pode ser atribuído a redução na absorção e redistribuição de Ferro e, consequentemente, na síntese de hemoglobina (Adham et al, 2000). Pois, a vitamina C participa na liberação do ferro da trasnferrina e ferritina, da forma oxidada para forma reduzida, que é subsequentemente, incorporada à hemoglobina e outros compostos essenciais, favorecendo o seu transporte no organismo (Delvin, 1998).…”