Regulation of the ASC system and Na+/K + pump activities in brown trout (Salmo trutta) hepatocytes
نویسندگان
چکیده
The present study investigates the regulation of Na+/K+ pump activity and alanine uptake in trout hepatocytes. Pump activity increased when cells were incubated in an amino-acid-free medium, while it was reduced in cells from fasted animals. Short-term exposure (3 h) to glucagon modified the activity of the pump in a complex seasonally dependent pattern: in experiments carried out in autumn and winter there was some inhibition, while in spring the pump was activated by this hormone. Pharmacological modification of levels of two intracellular signal transducers, namely cyclic AMP and Ca2+, always led to a reduction in pump activity. These experiments were conducted in May, when activation of the pump by glucagon exposure occurred. There is no apparent explanation for the mechanism by which this hormone modifies the activity of the pump. Glucagon also regulates the activity of system ASC (a Na+-dependent amino acid carrier with short-chain neutral amino acids as preferred substrates). This regulation also showed a seasonally dependent pattern, although the pattern was opposite to that found for the regulation of Na+/K+ pump activity.
منابع مشابه
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متن کامل
Growth and mortality of brown trout, Salmo trutta fario in Lar dam, Iran
The length-weight relationship, age, growth parameters, sex ratio, mortality and exploitation rate of Salmo trutta fario were determined in Lar dam. The sex ratio (male: female) was 1:1.84 which differed significantly from the expected 1:1. The length-weight regression was (females) and (males) indicating a negative allometric growth for both sexes. Growth parameters were estimated as L∞ = ...
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عنوان ژورنال:
- The Journal of experimental biology
دوره 199 Pt 11 شماره
صفحات -
تاریخ انتشار 1996