Changes in alkaline phosphatase isoenzyme activity in tissues and plasma of Atlantic salmon (Salmo salar) before and during smoltification and gonadal maturation

Abstract

Changes in tissue and plasma isoenzymes of alkaline phosphatase (ALP) were qualitatively and quantitatively determined for male and female Atlantic salmon parr, silvery parr, smolt, immature grilse, prespawning grilse and postspawning grilse using cellulose acetate electrophoresis, densitometry and spectrophotometry. Tissue ALP isoenzymes were isolated from intestine, kidney, bone, liver, and gonad and compared to plasma isoenzymes. Parr plasma displayed three isoenzymes from bone and liver (slow and fast). During smoltification, ALP activity increased in tissue extracts from liver, gonad, and kidney of males and females. Total plasma ALP activity also increased and was due to slow and fast liver isoenzymes. During ovarian development, total ALP plasma activity increased in females and was due mostly to liver isoenzymes and an incompletely identified isoenzyme or isoenzyme mixture (band 2). However, in males total ALP plasma activity did not increase during maturation and no band 2 was evident. In male and female maturing adult grilse, bone ALP activity declined and the isoenzyme band evident in parr plasma could not be detected. ALP activity declined in the plasma of postspawning males and females. In females this was due partly to the total clearance of band 2 from the plasma, together with lowered levels of liver isoenzymes. Treatment of postspawned grilse in February and March with triiodothyronine and thyroxine elevated plasma thyroid hormone levels and increased plasma ALP levels. In conclusion, plasma ALP isoenzyme activities change with physiological state, and knowledge of the conditions governing these changes is important when using these enzymes as a diagnostic tool.

Tartrate resistant acid phosphatase as a marker for scale resorption in rainbow trout, Oncorhynchus mykiss: effects of estradiol-17? treatment and refeeding

“…As expected, the rainbow trout intestine exhibited strong staining for ALP (Johnston et al 1994), whereas in the scales, only the skin was stained for ALP (data not shown).…”

“…Scales were sampled as described earlier, and fixed in 10% formalin in 0.05 M cacodylate buffer at pH 7.4, and stained using a 0.05 M 2-amino-2-methyl-1,3-propanediol solution (Sigma) containing 1 M naphtol AS BI phosphate sodium salt (Sigma) and 1.3 M fast blue RR (Sigma). Rainbow trout intestine was used as a positive control for this method (Johnston et al 1994).…”

Changes in hydrolytic enzyme activities of naïve Atlantic salmon Salmo salar skin mucus due to infection with the salmon louse Lepeophtheirus salmonis and cortisol implantation

“…These results were consistent with the observations reported in this study. In another study, changes in the levels of tissue and blood alkaline phosphatase isoenzymes were associated with smolting and gonadal development (Johnston et al 1994). However, alkaline phosphatase isoenzymes in skin and mucus were not examined.…”

Dietary phosphorus requirement of juvenile black seabream, Sparus macrocephalus

“…ALP is closely associated with the metabolism of Ca and P, and takes part in chondrogenic and osteoblastic activities in birds (Viñuela et al, 1991). It is influenced by many factors including water chemistry (Bowser et al, 1989), feed intake (Sauer and Haider, 1979), temperature (Sauer and Haider, 1977;Sakaguchi and Hamaguchi, 1979;Lie et al, 1988) and life stage (Johnston et al, 1994). Contrary to our results, Shearer and Hardy (1987) reported plasma ALP activity in rainbow trout was not significantly affected by feeding phosphorus sufficient and deficient diets (P b 0.05); however, Sakamoto and Yone (1980) found a low phosphorus intake by red sea bream increased plasma ALP activity.…”