The effect of heat on rat pineal hydroxyindole-O-methyl transferase activity

Summary Exposure of adult male rats to continuously elevated temperature of 32–34°C caused a significant decrease of HIOMT activity involved in the specific metabolic process of production of melatonin, considered an active pineal hormone. The effect was already evident after 24 h exposure and increased further during the next 48 h. The results obtained substantiate previous data that the pineal gland may be involved in the system regulating adaptation to extreme temperature changes.Acknowledgment. The authors are indebted to MissUte Schmidt for her excellent technical assistance.     

Redox enzyme models from polymerized aminoacyladenylates

Résumé Des modèles d'enzymes d'oxydoréduction ont été préparés par polymérisation des 20 aminoacyladénylates en présence de flavine mononucléotide, d'hème et de chlorophylle. L'addition du cofacteur flavinique au cours de la polymérisation modifie la composition en acides aminés du polymère obtenu. L'article offre une discussion sur les taux de réaction, les absorptions optiques et de dispersion rotatoire et les propriétés générales des modèles d'enzymes d'oxydoréduction.

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The support from a National Science Foundation Development Program grant to the University of Texas is gratefully acknowledged as is the assistance ofDirk Schenkkan and Mrs.Sandra Smith.