Somatotrophic diabetes: Insulin release responses to arginine and glucagon in dogs

Abstract

Growth hormone injected daily in 6 dogs for 6 days caused a 20-fold elevation in fasting serum immunoreactive insulin (IRI) without appreciable change in serum glucose in 1 day. In the somatotrophic diabetes that occurred after 2 days, the hyperinsulinaemia was maintained and the serum IRI/glucose (I/G) ratio declined from the early high level but remained elevated. During this treatment, in response to glucose infusion, the rise in serum IRI above the initially high fasting level was 16 times the normal. In response to glucagon, the rise in IRI was twice the normal and the rise in glucose was more prolonged, resulting in a decline in the I/G ratio. In response to arginine infusion, the rise in serum IRI was 8 times the normal and the rise in the I/G ratio was twice normal. Following a meal, the rise in serum IRI was 8 times the normal. Thus, with growth hormone treatment the insulin secretory responses to these stimulating factors were magnified over the already elevated fasting level of secretion. The insulin content of the pancreas was reduced to less than 10% of normal by growth hormone treatment for 6 days, due apparently to elevation of the rate of secretion over the rae of formation of insulin.

Metasomatotrophic diabetes and its induction: Basal insulin secretion and insulin release responses to glucose, glucagon, arginine and meals

“…The injection of arginine (0.4 g/kg body weight IV) in 5 dogs at about day 20 of metasomatotrophic dia- In this arginine test in normal dogs, as reported previously [12] serum IRI rapidly rose to over 4-fold and the I/G ratio rose 3-fold, with fractional rises in serum glucose and NEFA, of about 50%.…”

“…In the control period of 4 months duration, the dogs became accustomed to the laboratory conditions and the testing procedures. The tests were performed as described previously [12] about 17 h after a meal and were preceded by the withdrawal of two 6 ml samples of venous blood. Glucose (1.0 g/kg body weight) was given IV within one minute, as a 50% solution (W/V) in 0.154 mol NaC1/1, after allowing ample time for equilibration of the a and b anomers.…”

“…Arginine (0.4 g/kg body weight) (50% W/V of L-arginine monochloride in 0.154 mol NaC1/1) was injected IV within 2 rain and blood samples were taken at 5, 10, 15, 30, 60 and 120 min. Glucagon, 0.1mg/kg body weight (Lilly, Lot 258-234-B-167-1 in 0.154mol NaC1/1, 10mg/ml) was injected IV within seconds: blood samples were taken at 2, 5, 10, 15, 20, 30, 45 and 0012-186X/80/0018/0223/$01.20 was determined [12,17]. Frozen sections of liver and other tissues were fixed and stained for lipid with Oil Red 0 dye [18].…”

Alterations of biochemical and biomechanical properties of rat tail tendons caused by non-enzymatic glycation and their inhibition by dibasic amino acids arginine and lysine

“…Sensi et al [14] studied the in vitro inhibition of NEG by lysine, the main amino acid target in proteins for the initial Schiff base reaction. While the pharmacology and diagnostic use of arginine, another dibasic amino acid, for the management of diabetes patients is amply documented [15][16][17], its role as a potential inhibitor of NEG has not been investigated as yet. In contrast to lysine proteinbound arginine seems to be no target for the aldehyde to Schiff base pathway and, therefore, for NEG in vitro [18].…”

Secretion of Glucagon and Insulin in Hypophysectomized Rats: Effect of Tolbutamide

“…This combination of growth and functional deficiency suggests the malfunction of a negative feedback for a hypothetical insulotrophic factor: a situation comparable to the TSH-induced enlargement of the thyroid following pharma cologic block of thyroid hormone biosynthesis. A prime suspect in the produc tion of this factor is the anterior pituitary, since hypopituitarism is associated with decreased B cell activity and hypoinsulinism (1,13,22,30), while pituitary hyperfunction, pituitary extracts and especially growth hormone, increase the size and granule content of the B cells in hypophysectomized animals (22,30), and stimulate the secretion of insulin (6), even though they may induce diabetes (2,25). The relationship between anterior pituitary and A cells is less clear.…”