111: Studies on a hypothalamic islet-stimulating factor in childhood obesity

Abstract

The ventrolateral hypothalamus secretes a factor that in experimental animals stimulates insulin secretion both in vitro and in vivo. This hypothalamic humoral factor is also demonstrable in serum (Martin et al.: J. Endocrinol. 1973:58:681). We studied the activity of this factor in sera of obese children. Urea treated serum was fractionated through Amicon membranes and the serum fractions between 1,000-10,000 Daltons were tested for islet-stimulating activity by measuring insulin released by isolated rat islets exposed to 5.5. mM glucose plus the test fraction. So far we have analysed sera of 12 obese children. In two cases a significant stimulation of the islets has been found. The same children presented hyperinsulinemia at OGTT. One of these patients had become obese after operation of a hypothalamic tumor. The preliminary results indicate that a hypothalamic humoral factor may play a role in the etiology of some forms of childhood obesity Grant: Sigrid Juselius Foundation.