Circadian metabolic patterns in cultured hamster adrenal glands

1. 1. Circadian patterns in respiration and steroid secretion have been observed for hamster ( Mesocricetus auratus) glands which have been maintained in culture. 2. 2. Reversal of the lighting regimen for young animals reversed the phase profile of adrenal metabolic patterns. 3. 3. Cultured phase-reversed glands did not sustain the reversed metabolic pattern but re-established patterns intermediate between reversed and control times. 4. 4. The biorhythmic property of relative temperature independence was displayed by cultured glands. 5. 5. The secretory pattern profiles resembled respiratory patterns, but did not have the same phase relationships. 6. 6. The relationship between stimulated steroid secretion and oxygen consumption by the cultured glands must be indirect.