Evidence for selective release of somatostatin-14 and somatostatin-28(1-12) from rat hypothalamus.
Cysteamine administration to rats results in a marked depletion of hypothalamic somatostatin-14 (SS14) and a decrease of the potassium-evoked in vitro release of SS14 without a significant change in the content or release of somatostatin-28(1-12)-like immunoreactivity (SS28(1-12)-L1). Furthermore, cysteamine enhances the spontaneous release and markedly potentiates the potassium-evoked release of SS14 in the in vitro slice preparation. However, in vitro-administered cysteamine does not alter the spontaneous or potassium-evoked release of SS28(1-12)-LI. Immunohistochemical visualization of hypothalamic neuronal cell bodies and fibers following cysteamine administration shows a disappearance of the SS14 immunoreactive fibers and cell bodies with no apparent change in the SS28(1-12) immunoreactive fibers and cell bodies. These data suggest that, in rat hypothalamus, selective release of SS14 and SS28(1-12) can occur. The results are discussed in relation to possible sites of storage and release of the somatostatin-related peptides from synaptic nerve terminals.
D000818:Animals; D003543:Cysteamine / Q000494:pharmacology; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008856:Microscopy, Fluorescence; D010446:Peptide Fragments / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000378:metabolism*; D053561:Somatostatin-28
D010446:Peptide Fragments; D013004:Somatostatin; D003543:Cysteamine; D053561:Somatostatin-28; C037197:somatostatin 28-(1-12); D011188:Potassium