Effect of Hypophysectomy and Adrenalectomy on Glucagon and Insulin Concentration

Lan, Vo Van; Yamaguchi, Nobuyuki; García, M.J. López; Ramey, Estelle R.; Penhos, J. C.

doi:10.1210/endo-94-3-671

Cited by 48 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reduced serum insulin and elevated glucagon concentrations observed in our study agree with earlier findings in hypox rats (Van Lan et al 1974). Despite decrease in serum insulin, serum glucose and pancreatic insulin content per gram of tissue were not significantly different from the normal animals, as also reported by Malaisse et al (1968), and the insulin mRNA level was elevated, as demonstrated by ISH and Northern blot analysis.…”

Section: Discussionsupporting

confidence: 92%

See 1 more Smart Citation

The effect of hypophysectomy on pancreatic islet hormone and insulin-like growth factor I content and mRNA expression in rat

Jevdjović

Maake

Zwimpfer³

et al. 2005

Histochem Cell Biol

View full text Add to dashboard Cite

The growth arrest after hypophysectomy in rats is mainly due to growth hormone (GH) deficiency because replacement of GH or insulin-like growth factor (IGF) I, the mediator of GH action, leads to resumption of growth despite the lack of other pituitary hormones. Hypophysectomized (hypox) rats have, therefore, often been used to study metabolic consequences of GH deficiency and its effects on tissues concerned with growth. The present study was undertaken to assess the effects of hypophysectomy on the serum and pancreatic levels of the three major islet hormones insulin, glucagon, and somatostatin, as well as on IGF-I. Immunohistochemistry (IHC), in situ hybridization (ISH), radioimmunoassays (RIA), and Northern blot analysis were used to localize and quantify the hormones in the pancreas at the peptide and mRNA levels. IHC showed slightly decreased insulin levels in the b cells of hypox compared with normal, age-matched rats whereas glucagon in a cells and somatostatin in d cells showed increase. IGF-I, which localized to a cells, showed decrease. ISH detected a slightly higher expression of insulin mRNA and markedly stronger signals for glucagon and somatostatin mRNA in the islets of hypox rats. Serum glucose concentrations did not differ between the two groups although serum insulin and C-peptide were lower and serum glucagon was higher in the hypox animals. These changes were accompanied by a more than tenfold drop in serum IGF-I. The pancreatic insulin content per gram of tissue was not significantly different in hypox and normal rats. Pancreatic glucagon and somatostatin per gram of tissue were higher in the hypox animals. The pancreatic IGF-I content of hypox rats was significantly reduced. Northern blot analysis gave a 2.6-, 4.5-, and 2.2-fold increase in pancreatic insulin, glucagon, and somatostatin mRNA levels, respectively, in hypox rats, and a 2.3-fold decrease in IGF-I mRNA levels. Our results show that the fall of serum IGF-I after hypophysectomy is accompanied by a decrease in pancreatic IGF-I peptide and mRNA but by partly discordant changes in the serum concentrations of insulin and glucagon and the islet peptide and/or mRNA content of the three major islet hormones. It appears that GH deficiency resulting in a ''low IGF-I state'' affects translational efficiency of these hormones as well as their secretory responses. The maintenance of normoglycemia in the presence of reduced insulin and elevated glucagon serum levels, both of which would be expected to raise blood glucose, may result mainly from the enhanced insulin sensitivity, possibly due to GH deficiency and the subsequent decrease in IGF-I production.

show abstract

Section: Discussionsupporting

confidence: 92%

“…To our knowledge, no data are available regarding pancreatic glucagon content in hypox rats. Serum glucagon content in hypox rats has been reported in only one study, where it was found to be elevated (Van Lan et al 1974). Furthermore, we are not aware of any data on islet hormone gene expression in the pancreas of hypox rats.…”

Section: Introductionmentioning

confidence: 73%

The effect of hypophysectomy on pancreatic islet hormone and insulin-like growth factor I content and mRNA expression in rat

Jevdjović

Maake

Zwimpfer³

et al. 2005

Histochem Cell Biol

View full text Add to dashboard Cite

show abstract

“…These studies once again confirm the observation made by Houssay The lower plasma glucose levels 12 wk after hypoX may not have been the primary consequence of hypoglucagonemia, inasmuch as they were present 4 wk after hypoX, at which time both basal and argininestimulated IRG levels were slightly above normal, presumably in response to the hypoglycemia, as observed in rats by Van Lan et al (29). Nevertheless, one can argue that the absence of hyperglucagonemia sufficient to correct the hypoglycemia represents evidence of insufficient A-cell function.…”

Section: Discussionsupporting

confidence: 90%

“…Insulin was determined by the radioimmunoassay of Yalow and Berson (24), as modified by Herbert et al (25). Immunoreactive glucagon (IRG) was measured as described previously (26) with 30K antiserum, which is considered to be reactive with the C-terminal portion of the glucagon molecule (27,28) and which crossreacts only very weakly with gut glucagon-like immunoreactivity (29).…”

Section: Methodsmentioning

confidence: 99%

The Role of Glucagon Deficiency in the Houssay Phenomenon of Dogs

Nakabayashi

Dobbs

Unger³

1978

J. Clin. Invest.

View full text Add to dashboard Cite

A B S T R A C T Plasma glucose, immunoreactive glucagon (IRG), and insulin were measured in hypophysectomized dogs receiving cortisol and thyroid replacement therapy. 4 wk after hypophysectomy mean fasting plasma glucose levels had declined from 90+2 mg/100 ml to 64+2; fasting and arginine-stimulated insulin and IRG levels were, respectively, -50% lower and unchanged. 12 wk or more after hypophysectomy, despite lower plasma glucose levels, fasting and arginine-stimulated IRG levels were significantly below control dogs. Hypophysectomized and shamhypophysectomized dogs were subjected to total pancreatectomy. Postoperatively, in the sham-hypophysectomized, depancreatized dogs fasting glucose levels ranged from 300-500 mg/100 ml on 8-10 U/day of insulin; IRG levels averaged 215+29 pg/ml. The hypophysectomized, depancreatized dogs required 0-4 U/day and fasting glucose levels under 100 mg/100 ml were not uncommon, even without insulin; fasting IRG levels averaged 63+4 pg/ml (P < 0.001). During arginine infusion in sham-hypophysectomized, depancreatized dogs, IRG levels rose from 215+60 pg/ml to a peak of 404±+112 pg/ml; in hypophysectomized, depancreatized dogs, the base line IRG averaged 44+8 and the peak 110+25 pg/ml (P < 0.05). IRG levels in the venous effluent of the gastric fundus, the major source of nonpancreatic glucagon, reached a peak of 4,898±+-959 pg/ml in the sham-hypophysectomized, depancreatized group during arginine infusion and only 219+128 pg/ml in the hypophysectomized, depancreatized group. In three hypophysectomized, depancreatized dogs, a replacement infusion with glucagon for 10 h promptly increased hyperglycemia by 80-180 mg/100 ml and worsened glycosuria, evidence of a hepatic response to glucagon replacement. It is concluded that hypophysectomy somehow de-

show abstract

“…Barseghian & Levine (1980) have recently shown that physiological amounts of corticosterone strongly inhibit secretion of insulin and potentiate that of glucagon in the isolated perfused rat pancreas preparation. However interpretation of the actions that exogenous glucocorticoids may exert in vivo is complicated by the fact that their metabolic effects will also produce consequential changes in islet function; the consensus is that they stimulate the secretion of insulin under these conditions (Campbell et al 1966;Perley & Kipnis, 1966;Van Lan, Yamaguchi, Garcia, Ramey & Penhos, 1974). In some species prolonged treatment with glucocorticoids precipitates overt diabetes, whereas others, such as cats, dogs and calves tolerate large doses over long periods of time (Abelove & Paschkis, 1954;Comline et al 1970) and rats only become diabetic under these conditions if they have been partially pancreatectomized or are also force fed (Ingle, 1941;Ingle & Thorn, 1941).…”

Section: Discussionmentioning

confidence: 99%

Pancreatic endocrine function in cortisol‐treated thyroidectomized calves.

Bloom¹,

Edwards²,

Fielding³

1981

The Journal of Physiology

View full text Add to dashboard Cite

SUMMARY1. Pancreatic endocrine function has been investigated in thyroidectomized calves given exogenous cortisol (2'0 mg . kg-. day-') in order to produce overt signs of diabetes.2. Whenever this diabetic syndrome was induced it was associated with falling plasma insulin concentrations. A few days later, there was a significant rise in the post-absorptive concentration ofboth pancreatic glucagon and pancreatic polypeptide (PP) in the arterial plasma. Elevated levels of both hormones invariably persisted until the animals were given thyroxine.3. Each of the pancreatic endocrine responses to cortisol was reversed by daily administration ofthyroxine (25 jug . kg-' . day-') and the plasma glucose concentration was restored to normal within a few days.4. Starvation was found to be an extremely effective way of reducing both the plasma glucose and glucagon concentration of diabetic calves without apparently affecting the concentration of either insulin or PP.5. Neurally mediated release of insulin in response to 2-deoxyglucose, but not of either pancreatic glucagon or PP, was found to be defective in diabetic calves and recovered in response to thyroxine.6. These results suggest that the primary defect that leads to the development of this diabetic syndrome in cortisol-treated thyroidectomized calves is failure of insulin release but that this is associated with consequential changes in the rates at which both glucagon and PP are released from the pancreas.

show abstract

Effect of Hypophysectomy and Adrenalectomy on Glucagon and Insulin Concentration

Cited by 48 publications

References 0 publications

The effect of hypophysectomy on pancreatic islet hormone and insulin-like growth factor I content and mRNA expression in rat

The effect of hypophysectomy on pancreatic islet hormone and insulin-like growth factor I content and mRNA expression in rat

The Role of Glucagon Deficiency in the Houssay Phenomenon of Dogs

Pancreatic endocrine function in cortisol‐treated thyroidectomized calves.

Contact Info

Product

Resources

About