TY - JOUR
T1 - Induction of Taurocholate Release from Isolated Rat Hepatocytes in Suspension by α‐Adrenergie Agents and Vasopressin
T2 - Implications for Control of Bile Salt Secretion
AU - Gewirtz, David A.
AU - Randolph, Joyce K.
AU - Goldman, I. David
PY - 1984
Y1 - 1984
N2 - Hepatocytes incubated with 25 μM. [3H]taurocholate rapidly deplete the extracellular medium of [3H]taurocholate and achieve a steady‐state level of intracellular bile salt within 15 min. Exposure of cells at steady state ith extracellular taurocholate to the catecholamines norepinephrine or epinephrine results in release of 3H from the cells into the incubation medium; the 3H released represents almost exclusively unmetabolized [3H]taurocholate. The hierarchy of effectiveness of the catecholamines, norepinephrine ≈ epinephrine > phenylephrine ≫ isoproterenol, is indicative of an α‐adrenergic mechanism. Induction of [3H]taurocholate release by norepinephrine is inhibited by the β‐antagonists phenoxybenzamine and phentolamine and by chlorpromazine, but is not affected by the β‐antagonist propranolol, further supporting an α‐adrenergic basis for this phenomenon. Arginine vasopressin, at concentrations of 1 ± 10−9 M and greater, also induces bile salt release. Classical α‐ and β‐antagonists have minimal effects on vasopressin induced bile salt release. While the peptide hormones angiotensin and oxytocin are, alone, relatively ineffective inducers of bile salt release, oxytocin potentiates the induction of bile salt release by vasopressin, suggesting complex interactions with membrane receptor function. Further studies assessing the interaction of sympathetic neurotransmitters and peptide hormones with bile salt transport and release in the hepatocyte may provide insight into the regulation of hepatic secretory function in the intact animal.
AB - Hepatocytes incubated with 25 μM. [3H]taurocholate rapidly deplete the extracellular medium of [3H]taurocholate and achieve a steady‐state level of intracellular bile salt within 15 min. Exposure of cells at steady state ith extracellular taurocholate to the catecholamines norepinephrine or epinephrine results in release of 3H from the cells into the incubation medium; the 3H released represents almost exclusively unmetabolized [3H]taurocholate. The hierarchy of effectiveness of the catecholamines, norepinephrine ≈ epinephrine > phenylephrine ≫ isoproterenol, is indicative of an α‐adrenergic mechanism. Induction of [3H]taurocholate release by norepinephrine is inhibited by the β‐antagonists phenoxybenzamine and phentolamine and by chlorpromazine, but is not affected by the β‐antagonist propranolol, further supporting an α‐adrenergic basis for this phenomenon. Arginine vasopressin, at concentrations of 1 ± 10−9 M and greater, also induces bile salt release. Classical α‐ and β‐antagonists have minimal effects on vasopressin induced bile salt release. While the peptide hormones angiotensin and oxytocin are, alone, relatively ineffective inducers of bile salt release, oxytocin potentiates the induction of bile salt release by vasopressin, suggesting complex interactions with membrane receptor function. Further studies assessing the interaction of sympathetic neurotransmitters and peptide hormones with bile salt transport and release in the hepatocyte may provide insight into the regulation of hepatic secretory function in the intact animal.
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U2 - 10.1002/hep.1840040207
DO - 10.1002/hep.1840040207
M3 - Article
C2 - 6142855
AN - SCOPUS:0021236565
SN - 0270-9139
VL - 4
SP - 205
EP - 212
JO - Hepatology
JF - Hepatology
IS - 2
ER -