Abstract
In vitro effect of serotonin on glycogen level of rat diaphragm was investigated. Serotonin stimulated glycogen formation in phosphate-buffered saline, but not in Krebs-Ringer bicarbonate medium.The effect of serotonin disappeared under glycogenolytic condition.Glucose uptake was never augmented by serotonin even in the tissue in which glycogenetic action of serotonin was exhibited.Suppressive action of serotonin on glucose uptake manifested itself in diabetic as well as in glucose-fed non-diabetic rat tissue.The negative interaction was noted between glycogenetic activity of insulin and serotonin.The mechanism involved in in vitro effect of serotonin with respect to stimulation of glycogenesis and inhibition of glucose utilization is discussed along with the comparison to insulin.
