Neurotensin and substance-P: Effects on plasma insulin and glucagon levels

The histaminergic mechanism of neurotensin-induced glucagon release from isolated rat pancreatic islets.

“…This is consistent with the previous in vivo studies which showed neurotensin-induced hyperglucagonemia in rats (Brown et al, 1976) , 1976). However, as we reported previously (Shibata et al, 1978;, the effect of neurotensin on glucagon release depends upon the concentration of glucose in the incubation medium, being rather inhibitory in a low glucose concentration (1.67mM) and most stimulatory in a high glucose concentration (16.7mM).…”

“…It was found in the present study that histamine stimulated glucagon release from the isolated islets of rats (Table 1), and this is consistent with the results reported by Pontiroli et al (1979). In addition, neurotensin-induced glucagon release was completely blocked by metiamide, an H2-receptor antagonist, but rather stimulated by diphenhydramine, an H1-receptor antagonist, which had been reported before (Itatsu et al, 1979), being inconsistent with the results of Brown et al (1976) and partially compatible with the those of Nagai et al (1978). According to the present data on 30 min incubation, diphenhydramine was likely to accelerate neurotensin-induced glucagon release.…”

“…This peptide has been shown to induce hyperglycemia (Brown et al, 1976;Ukai et al, 1976;Nagai et al, 1976;Sasaki et al, 1980), in association with low insulin and high glucagon levels in systemic plasma of rats (Brown et al, 1976) and with high insulin and high glucagon levels in the portal vein plasma (Ukai et al, 1977) or in the pancreatic vein plasma (Kaneto et al, 1978) of dogs.…”

“…Its effect on insulin release has been variously reported as inhibitory (Moltz et al, 1977) and stimulatory (Dolais- Kitabgi et al, 1979). Although the mechanism of the neurotensin-induced release of pancreatic hormones is not fully understood, the histaminergic mechanism has been thought to be involved in neurotensin-induced hyperglucagonemia, based on in vivo studies in rats (Brown et al, 1976;Nagai et al, 1978).…”

Immunoreactive Dog C-Peptide Level in the Pancreatic Vein

“…It is well known that neurotensin influences the endocrine pancreas Brown, Villarreal and Vale 1976;Patton, Brown, Dobbs, Vale and linger 1976;Nagai and Frohman 1976;Ukai, Inoue and Itatsu 1977). In the present study, a large amount (10 Mg/kg) of neurotensin caused biphasic, parallel secretions of IRI and CPR in the pancreatic vein.…”