Circadian rhythm of plasma prolactin, growth hormone, glucose and free fatty acid in juvenile kokanee salmon, Oncorhynchus nerka

Plasma prolactin levels during smolting in Atlantic salmon, Salmo salar

“…data, 1987). The discrepancy with other data indicating a marked circadian rhythm in juvenile kokanee salmon may come from the use, in this previous study, of a heterologous radioimmunoassay for PRL measurement or possibly by a species difference (Leatherland et al, 1974). Interestingly, in our study this absence of PRL die1 variation was observed during the smolting period at three different dates corresponding to pre-smolt, smolt and post-smolt.…”

Plasma prolactin levels during smolting in Atlantic salmon, Salmo salar

“…data, 1987). The discrepancy with other data indicating a marked circadian rhythm in juvenile kokanee salmon may come from the use, in this previous study, of a heterologous radioimmunoassay for PRL measurement or possibly by a species difference (Leatherland et al, 1974). Interestingly, in our study this absence of PRL die1 variation was observed during the smolting period at three different dates corresponding to pre-smolt, smolt and post-smolt.…”

Melatonin Modulates Secretion of Growth Hormone and Prolactin by Trout Pituitary Glands and Cells in Culture

“…Our results are consistent with previous findings showing that 1) pinealectomy affected PRL content in the pituitary (2, 13); 2) daytime melatonin administration reduced by 10-fold pituitary PRL content (the effects depended on the photoperiod (13): and 3) PRL cell activity and PRL plasma levels vary during the 24-h light-dark cycle; higher rates are usually found at dawn or midday than during nighttime (33,44,45). We suggest that nocturnal melatonin production contributes to lower PRL secretion, maybe by a direct action on PRL cells, and that the release of this inhibition during day favors an increase in PRL release.…”

Circadian pattern of hepatosomatic index, liver glycogen and lipid content, plasma non-esterified fatty acid, glucose, T3, T4, growth hormone and cortisol concentrations in Oncorhynchus mykiss held under different photoperiod regimes and fed using demand-feeders

“…9) (as measured by means of a sensitive homologous ELISA based on monoclonal antibodies), are in general agreement with earlier reports of higher somatotropic cell activity in rainbow trout and tilapia (Sarotherodon mossambicus), based on histological criteria (Leatherland and Nuti 1982;Carrillo et al 1980), and higher plasma GH concentrations, measured using a heterologous RIA, in kokanee salmon during the early scotophase (Leatherland et al 1974).…”

Plasma prolactin levels during smolting in Atlantic salmon, Salmo salar

“…data, 1987). The discrepancy with other data indicating a marked circadian rhythm in juvenile kokanee salmon may come from the use, in this previous study, of a heterologous radioimmunoassay for PRL measurement or possibly by a species difference (Leatherland et al, 1974). Interestingly, in our study this absence of PRL die1 variation was observed during the smolting period at three different dates corresponding to pre-smolt, smolt and post-smolt.…”

Melatonin Modulates Secretion of Growth Hormone and Prolactin by Trout Pituitary Glands and Cells in Culture

“…Our results are consistent with previous findings showing that 1) pinealectomy affected PRL content in the pituitary (2, 13); 2) daytime melatonin administration reduced by 10-fold pituitary PRL content (the effects depended on the photoperiod (13): and 3) PRL cell activity and PRL plasma levels vary during the 24-h light-dark cycle; higher rates are usually found at dawn or midday than during nighttime (33,44,45). We suggest that nocturnal melatonin production contributes to lower PRL secretion, maybe by a direct action on PRL cells, and that the release of this inhibition during day favors an increase in PRL release.…”

Circadian pattern of hepatosomatic index, liver glycogen and lipid content, plasma non-esterified fatty acid, glucose, T3, T4, growth hormone and cortisol concentrations in Oncorhynchus mykiss held under different photoperiod regimes and fed using demand-feeders

“…9) (as measured by means of a sensitive homologous ELISA based on monoclonal antibodies), are in general agreement with earlier reports of higher somatotropic cell activity in rainbow trout and tilapia (Sarotherodon mossambicus), based on histological criteria (Leatherland and Nuti 1982;Carrillo et al 1980), and higher plasma GH concentrations, measured using a heterologous RIA, in kokanee salmon during the early scotophase (Leatherland et al 1974).…”

Plasma prolactin levels during smolting in Atlantic salmon, Salmo salar

“…data, 1987). The discrepancy with other data indicating a marked circadian rhythm in juvenile kokanee salmon may come from the use, in this previous study, of a heterologous radioimmunoassay for PRL measurement or possibly by a species difference (Leatherland et al, 1974). Interestingly, in our study this absence of PRL die1 variation was observed during the smolting period at three different dates corresponding to pre-smolt, smolt and post-smolt.…”

Melatonin Modulates Secretion of Growth Hormone and Prolactin by Trout Pituitary Glands and Cells in Culture

“…Our results are consistent with previous findings showing that 1) pinealectomy affected PRL content in the pituitary (2, 13); 2) daytime melatonin administration reduced by 10-fold pituitary PRL content (the effects depended on the photoperiod (13): and 3) PRL cell activity and PRL plasma levels vary during the 24-h light-dark cycle; higher rates are usually found at dawn or midday than during nighttime (33,44,45). We suggest that nocturnal melatonin production contributes to lower PRL secretion, maybe by a direct action on PRL cells, and that the release of this inhibition during day favors an increase in PRL release.…”

Circadian pattern of hepatosomatic index, liver glycogen and lipid content, plasma non-esterified fatty acid, glucose, T3, T4, growth hormone and cortisol concentrations in Oncorhynchus mykiss held under different photoperiod regimes and fed using demand-feeders

“…9) (as measured by means of a sensitive homologous ELISA based on monoclonal antibodies), are in general agreement with earlier reports of higher somatotropic cell activity in rainbow trout and tilapia (Sarotherodon mossambicus), based on histological criteria (Leatherland and Nuti 1982;Carrillo et al 1980), and higher plasma GH concentrations, measured using a heterologous RIA, in kokanee salmon during the early scotophase (Leatherland et al 1974).…”