Effects of hypophysectomy and cortisol on the catecholamine biosynthesis and catecholamine content in chromaffin tissue from rainbow trout, Salmo gairdneri.
The in vitro activities of dopamine beta-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT) were determined in the chromaffin tissue of hypophysectomized and cortisol-treated rainbow trout, Salmo gairdneri. In addition, the content of adrenaline and noradrenaline was estimated. DBH activity increased after both hypophysectomy and cortisol administration. The increased activity after hypophysectomy was restored with administration of pituitary extract, ADP. The PNMT activity seemed to increase slightly after hypophysectomy, while the activity remained unchanged after cortisol administration. A small decrease in catecholamine content was seen after hypophysectomy or treatment with cortisol but the A/NA ratio was not changed. A regulation of the biosynthesis of catecholamines in trout chromaffin tissue is suggested and discussed in relation to mammalian conditions.
D000818:Animals; D002395:Catecholamines / Q000032:analysis / Q000096:biosynthesis*; D002838:Chromaffin System / Q000201:enzymology / Q000378:metabolism*; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D004837:Epinephrine / Q000032:analysis; D006854:Hydrocortisone / Q000008:administration & dosage*; D007016:Hypophysectomy; D009638:Norepinephrine / Q000032:analysis; D010625:Phenylethanolamine N-Methyltransferase / Q000378:metabolism; D012487:Salmonidae / Q000502:physiology*; D014337:Trout / Q000502:physiology*
D002395:Catecholamines; D004299:Dopamine beta-Hydroxylase; D010625:Phenylethanolamine N-Methyltransferase; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine