Insulin administration in the frog Rana tigrina: studies on the blood glucose and the histology of the endocrine pancreas.
The effect of various doses of insulin (25-, 50-, and 150 U/kg body weight) on the blood glucose level and islet-cytology of the frog Rana tigrina was studied until 96 h. Following the hormonal administration the frogs exhibited hypoglycemia, abnormal neuromuscular activity and degranulation of both the insulin secreting beta- and glucagon secreting alpha-(alpha2-) cells of the pancreatic islets. The action of insulin was dose and temperature dependent; the higher the dose and temperature, the greater the hypoglycemia and atrophy of islet tissue. The insulin-induced convulsive activity appears to be due to the direct action of this hormone on the nervous system; the shocks are not influenced by thermal variation. The great sensitivity of Rana tigrina to exogenous insulin seems to be related to only a few alpha2-cells in the endocrine pancreas and consequently, a smaller amount of circulating glucagon in this animal.
D000818:Animals; D001001:Anura; D001786:Blood Glucose / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005934:Glucagon / Q000378:metabolism; D007003:Hypoglycemia / Q000139:chemically induced; D007328:Insulin / Q000008:administration & dosage*; D007515:Islets of Langerhans / Q000187:drug effects* / Q000473:pathology; D010179:Pancreas / Q000187:drug effects; D011898:Ranidae; D012640:Seizures / Q000139:chemically induced; D013696:Temperature
D001786:Blood Glucose; D007328:Insulin; D005934:Glucagon