Figure 3. Effects of bilateral microinjection of methscopolamine into the lateral hypothalamic nucleus on pancreatic secretion in conscious rats.

A, microinjection of methscopolamine (MSCP) into the lateral hypothalamic nucleus (LH) resulted in a significant decrease in unstimulated pancreatic secretion, indicating that basal cholinergic tone in the hypothalamus regulates basal pancreatic secretion. B, time course of peptone-induced pancreatic secretion in the presence and absence of MSCP. C, cumulative net increases in pancreatic protein output. MSCP injection into the LH significantly reduced basal pancreatic protein secretion and peptone-stimulated pancreatic protein secretion, suggesting that muscarinic cholinergic receptors in the hypothalamus are involved in mediating pancreatic secretion. Values are means ± S.E.M. for 4 rats in each group.