The pancreatic islets in spontaneously hypertensive rats: islet blood flowand insulin production

Citation
M. Iwase et al., The pancreatic islets in spontaneously hypertensive rats: islet blood flowand insulin production, EUR J ENDOC, 144(2), 2001, pp. 169-178
Citations number
47
Categorie Soggetti
Endocrinology, Nutrition & Metabolism
Journal title
EUROPEAN JOURNAL OF ENDOCRINOLOGY
ISSN journal
08044643 → ACNP
Volume
144
Issue
2
Year of publication
2001
Pages
169 - 178
Database
ISI
SICI code
0804-4643(200102)144:2<169:TPIISH>2.0.ZU;2-5
Abstract
The aim of the study was to investigate if hypertension affects pancreatic islet blood flow and endocrine function. For this purpose. spontaneously hy pertensive rats (SHR) were compared with normotensive control Wistar-Kyoto rats (WKY). Both islet size and islet cell replication in 4-month-old SHR w as increased compared with WKY. The (pro)insulin biosynthesis was reduced i n islets isolated from SHR, whereas the insulin content was unchanged. A hy perinsulinemic response to glucose in vivo was observed in 4- and 12-month- old SHR. Pancreatic blood flow, measured using a microsphere technique, was lower in. SHR than in WKY in rats aged 5 weeks. 4 months or 1 year. Islet blood flow was lower in 4-month-old and 1-year-old SHR. In 4-month-old anim als, islet blood flow was unaffected by administration of enalaprilate and prazosin in both strains, but was markedly decreased by the administration of N-G-methyl-L-argimine. It was concluded that the islets of SHR have a de creased insulin production in vitro and a decreased islet blood perfusion. The reasons for this are likely to be multifactorial. Because SHR maintaine d an essentially normal glucose tolerance, an adaptation of the beta -cells to the metabolic and hemodynamic changes imposed by hypertension occurred.