Centrally applied atrial natriuretic factor diminishes bile secretion in the rat

BIANCIOTTI LG; VATTA MS; VESCINA C; TRIPPODI V; SABBATINI M; FERNADEZ BE

REGULATORY PEPTIDES

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2001 vol. 102 p. 127 - 133

0167-0115

Little is known about the role of centrally applied peptides in the regulation of bile secretion. We previously reported that theintravenous injection of atrial natriuretic factor ?ANF. reduces bile acid dependent flow without affecting portal venous pressure in therat. In the present work, we studied the effects of centrally applied ANF on bile secretion and the possible pathways involved. Rats werecannulated in the brain lateral ventricle for the administration of 1, 10 and 100 ngrml ANF. After 1 week, the common bile duct wascannulated and bile samples were collected every 15 min for 60 min after the administration of ANF. The excretion rate of various biliarycomponents was assessed. Bile secretion experiments were also performed after bilateral truncal vagotomy or atropine administration toevaluate the participation of a vagal pathway. In addition, the role of the sympathetic system was addressed by combined administrationof propranolol and phentolamine. Centrally applied ANF did not modify blood pressure but diminished bile flow and bile acid output. Italso reduced sodium and potassium secretion but did not modify protein or phospholipid excretion. Neither bilateral truncal vagotomy noratropine administration abolished ANF response. Furthermore, combined administration of adrenergic antagonists did not alter ANFinhibitory effect on bile flow. In conclusion, centrally applied ANF reduced bile acid dependent flow not through a vagal or adrenergicpathway in the rat, suggesting the involvement of a peptidergic pathway.