Diabetogenic role of insulin's counterregulatory hormones in the isletectomized, diabetic goby.

摘要: In an experimental model of insulin-dependent diabetes mellitus (IDDM) in the teleost fish, goby Gillichthys mirabilis, isletectomy procedure completely removes pancreatic endocrine tissue without affecting exocrine acini or other essential tissues. Interestingly, isletectomized (Ix) gobies do not exhibit a significant hyperglycemia until 10–15 d after this procedure, suggesting lack initial diabetogenic actions factor(s). Administering exogeneous glucagon otherwise nonsymptomatic 7-d Ix gobies, however, induces hyperglycemic state comparable to that severely diabetic rats (after 20 post-Ix). The spontaneously arising observed between 10 and 15d post-Ix, on hand, is significantly correlated with increasing serum cortisol concentrations, both exhibiting sustained elevated levels (approx 23 mmol/L >100 ng/mL, respectively) at 20- 25-d post-Ix. Exogenous treatment also induced nonsymptomatic, gobies. By contrast, growth hormone (GH) had no detectable effect Serum ammonia, principal nitrogenous waste species, were affected by but reduced slightly GH (30% reduction; p<0.05). Cortisol treatment, increased ammonia twofold, glucocorticoid negative nitrogen balance. These results indicate counterregulatory hormones—glucagon cortisol—are effective factors goby, capable driving metabolic imbalance IDDM.