Further Studies on Cold-Induced Release of Vasopressin from Isolated Bovine Neurosecretory Granules

Publisher Website
Google Scholar
Abstract
Neurosecretory granules (NSG) were preparedfrom the bovine neurohypophysis either at 25 or 0°C. The yield of vasopressor activity associated with NSG prepared at 25°C was twice as much as the yield at 0°C. The granules prepared at room temperature were also much more susceptible to lysis by cold temperature and by hypotonicity than granules prepared at 0°C. The cold temperature-induced release of vasopressin from NSG prepared at room temperature can be potentiated by hypotonic medium. Release of hormone induced by low temperature or hypotonicity can be partially inhibited by long-term incubation in sucrose medium. A wide variety of cations and anions (including Na+, Li+, Tris+, Ca2+, OAc–, SO42– and SCN-) can substitute for K+ or Cl– for the cold temperature-induced release. La3+, methylsulfate and succinate partially inhibited the response. Lauryl alcohol is very effective in inhibiting the cold-induced release of vasopressin from NSG. Vasopressin release can also be induced with the temperature kept constant at O°C by changing the incubation medium from isotonic sucrose (where little hormone release occurs) to an ionic medium. This effect is also inhibited by lauryl alcohol. Some possible mechanisms responsible for cold temperature-induced vasopressin release are discussed.

This publication has 0 references indexed in Scilit: