[Effects of electrical lesioning of hippocampal CA3 region and anterior commissura hippocampi fornix on plasma insulin level and islet cells in the rat].
Bilateral electrical lesioning of the hippocampal CA3 region (HCA3-EL) or anterior commissura hippocampi (ACHF-EL) caused marked elevations in plasma basal levels of insulin. 2 weeks later, fasting blood glucose levels were also augmented with decreased glucose tolerance. In contrast, the secretory response of pancreatic B cells to glucose stimulation was markedly enhanced. Following intravenous glucose tolerance test (IVGTT), the relative amounts of glucagon-like and insulin-like immunoreactants were reduced in the pancreatic islets of both HCA3-EL and ACHF-EL rats in comparison with the controls. In the HCA3-EL group, the relative amounts of somatostatin-like immunoreactants and gross numbers of such immunostained cells in islets were also decreased as compared with the control. No difference was seen in pancreatic-polypeptide-like immunoreactivities as assessed by immunohistochemistry plus microphotometry method. The above results suggest strongly that HCA3 and ACHF exert a tonic inhibitory action on the insulin secretion in the rat.
Department of Physiology, 4th Military Medical University, Xi'an.
K
K
Jiao
Y L
YL
Zhu
Q
Q
Mei
W H
WH
Zhang
F Z
FZ
Wang
D000818:Animals; D005260:Female; D005934:Glucagon / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006624:Hippocampus / Q000502:physiology*; D007150:Immunohistochemistry; D007328:Insulin / Q000097:blood*; D007515:Islets of Langerhans / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013004:Somatostatin / Q000378:metabolism
D007328:Insulin; D010455:Peptides; C029993:somatostatin-like peptides; D013004:Somatostatin; D005934:Glucagon; D005947:Glucose