The ‘pancreotropic’ action of anterior pituitary extracts

Richardson, K. C.; Young, F. G.

doi:10.1113/jphysiol.1937.sp003564

Cited by 65 publications

(9 citation statements)

References 4 publications

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“…(average 9.9); the highest recorded level was twenty-eight in a child whose fasting level was 11 ng. In adults tested in similar manner the maximum level often exceeds 30 …”

Section: Plasma Growth Hormone In Childhoodmentioning

confidence: 97%

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Insulin Secretion in Rats with Elevated Levels of Circulating Growth Hormone Due to MtT-W15 Tumor

1968

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Circulating levels of growth hormone (GH) in "WistarFurth rats bearing the MtT-\V15 tumor are twenty to thirty times higher than normal. The effect of constantly elevated levels of GH on the pancreatic islets was studied. Tumor-bearing rats (TR) and normal controls (C) were pair-fed for seven weeks. In TR, fasting serum levels of GH and insulin were 599 ± 157 ng./ml. and.142 ± 43 /iU./ml., respectively, and only 18.2 ± 1.9 ng./ml. and 26.9 ± 7.9 /iU./ml., respectively, in the controls. The islets of TR were enlarged with an islet/acinar ratio of 3.38 per cent (C: 0.82 per cent). The extracted pancreatic insulin was 9.84 ± 0.9 mU./mg. (C: 5.36 ± 0.4 mU./mg.). Incubated slices or isolated islets of TR pancreas released greater amounts of insulin when submitted to glucose stimulation. Incorporation of labeled leucine into insulin was increased also in TR. An exaggerated insulin response to a glucose load was found in vivo (peak value at 30 min., TR: 183 dt 42.5 fiU./ml; C: 71 ± 17.9 /*U/ml.). None of the TR became diabetic, however, and two to six weeks after removal of the tumors serum GH levels had returned to normal (17.2 /ig./ml.) as had insulin levels both fasting (19.0 /iU/ml.) and following a glucose load (56.4 fiU./mg.). Insulin output by incubated pancreas decreased 50 per cent (26 fiU./mg.). The islet/acinar ratio returned to normal but the insulin content remained high. These re g "ltft mAi.. cate that in animals exposed to hjyh levels of endogenous GH there is an increased responsiveness of the islets to glu-UTABETES J/:bol-OV, lNovember, !Vo8.

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“…(average 9.9); the highest recorded level was twenty-eight in a child whose fasting level was 11 ng. In adults tested in similar manner the maximum level often exceeds 30 …”

Section: Plasma Growth Hormone In Childhoodmentioning

confidence: 97%

“…This value is in keeping with previous observations on normal rat pancreas using Chalkley's technic 29 and by the camera lucida procedure. 30 Tumor-bearing rats had a significantly larger islet volume with a ratio of 3.38. After removal of the tumor the islet/acinar ratio returned toward normal.…”

Section: Body Weight and Food Intakementioning

confidence: 98%

Insulin Secretion in Rats with Elevated Levels of Circulating Growth Hormone Due to MtT-W15 Tumor

1968

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“…In intact rats, the islets can be made to grow by the injection of crude saline extracts of the pituitary gland (Richardson and Young, 27 Haist and colleagues, 21 and in hypophysectomized rats also the injection of crude saline extracts or of purified growth hormone preparations, leads to an increase in islet tissue. 28 The thyroid gland also influences the islets and probably the pituitary thyrotropic material would do likewise.…”

Section: The Source Of Insulinmentioning

confidence: 98%

Insulin: The Banting Memorial Lecture 1952

Best

1952

Diabetes

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“…On grafting it to the neck of a pancreatectomized dog it will not lower the high blood sugar as does a graft of a normal dog pancreas (Houssay and Foglla, 1936). Richardson and Young (1938) and Richardson ( , 1940 have found that the first signs of damage in the Langerhans' islets are a partial or total disappearance of the granules of the beta cells; hydropic degeneration of these cells, increased mitosis in some of the islets, and vacuollzation of the epithelium of the intralobar ducts. When diabetes does not appear the only changes are the vacuolization of the epithelium of the ducts and a small decrease of the granules of the B cells.…”

mentioning

confidence: 99%

The Hypophysis and Secretion of Insulin

Houssay

Foglia

Smyth

et al. 1942

Journal of Experimental Medicine

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The ability of the pancreas, from various types of dogs, to correct diabetic hyperglycemia has been studied (Table XI). The pancreas from one animal was united by a vascular union with the neck blood vessels of another dog which had been pancreatectomized for 20 hours. The time necessary to reduce the blood sugar level to 120 mg. per cent was determined. 1. Pancreas from 6 hypophysectomized dogs produced a normal insulin secretion, showing that an anterior pituitary hormone is not necessary for its production or maintenance. 2. In 14 of 17 normal dogs given anterior pituitary extract for 3 or more consecutive days and presenting diabetes (fasting blood sugar 150 mg. per cent or more) the pancreas showed diminished insulin production. 3. In animals which remained diabetic after discontinuing the injections of hypophyseal extract, the pancreas islands were markedly pathologic and the insulin secretion was practically nil. 4. When hyperglycemia existed on the 2nd to 5th day but fell later, the insulin secretion of 5 dogs was normal in 2, supernormal in 1, and less than normal in 2. Histologic examination showed a restoration of beta cells. 5. In 14 dogs resistant to the diabetogenic action of anterior pituitary extract, as shown by little or no change in blood sugar, the pancreatic secretion of insulin was normal in 6 cases, supernormal in 3, and subnormal in 5 cases. Clear signs of hyperfunction of B cells were observed. In 6 resistant animals a high blood sugar (150 mg. per cent) appeared shortly before transplanting, but insulin secretion was normal in 4, supernormal in 1, and subnormal in 1 case. 6. With one injection of extract and 1 day of hyperglycemia the capacity of the pancreas to secrete insulin was not altered. 7. A high blood sugar level lasting 4 days does not alter the islets. The hypophyseal extract acts, therefore, by some other mechanism. In normal dogs, the continuous intravenous infusion of glucose for 4 days maintained the blood sugar at levels as high as those after pituitary extract. In these animals the B cells were hyperplastic and insulin secretion normal. 8. Anterior hypophyseal hyperglycemia is due at first to extrapancreatic factors which are the most important, and last only during the injections of extracts. Pancreatic factors appear afterwards and are responsible for permanent diabetes. Hypophyseal extract produces histological changes in many tissues and damages the Langerhans islands. The coexistent high blood sugar probably exhausts the B cells and exaggerates their injury. 9. In all cases there is a relation between the cytology of the islet B cells and the insulin secreting capacity.

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The ‘pancreotropic’ action of anterior pituitary extracts

Cited by 65 publications

References 4 publications

Insulin Secretion in Rats with Elevated Levels of Circulating Growth Hormone Due to MtT-W15 Tumor

Insulin Secretion in Rats with Elevated Levels of Circulating Growth Hormone Due to MtT-W15 Tumor

Insulin: The Banting Memorial Lecture 1952

The Hypophysis and Secretion of Insulin

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