Growth Hormone in Relation to Diabetic Retinopathy

Powell, Elinor D. U.; Frantz, Andrew G.; Rabkin, Mitchell T.; Field, Richard A.

doi:10.1056/nejm196610272751703

Cited by 59 publications

(20 citation statements)

References 17 publications

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“…GH secretion was decreased and the GH response to hypoglycemia absent, as reported previously in monkey [31] and human [30], The absence of a GH response to hypoglycemia after stalk section is not surprising since the response is mediated by the hypothal amus; complete disconnection of the medial basal hypo thalamic area shows the same effect [12. 22].…”

Section: Discussionsupporting

confidence: 68%

Section of the Pituitry Stalk in the Rhesus Monkey

et al. 1980

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The effects of pituitary stalk section on anterior pituitary secretion were studied in 20 female rhesus monkeys. Vascular connections between the hypothalamus and the pituitary gland were permanently interrupted in all but 4 animals. Prolactin levels rose rapidly and remained significantly elevated in all effectively stalk-sectioned animals for as long as the observation period (up to 3 years). Only smaller and transient elevations of prolactin were seen in the animals in which revascularization of the anterior pituitary gland had occurred. Growth hormone and cortisol were significantly decreased after stalk section, and were not released by insulin. Radioimmunoassayable luteinizing hormone (LH) levels decreased following surgery and, by bioassay, LH became undetectable within 5 weeks after stalk section, indicating that gonadotropin-releasing hormone is essential for the viability of the gonadotrope. The results indicate that plasma prolactin concentrations can be used to monitor completeness of pituitary gland isolation from direct hypothalamic influence. Stalk-sectioned monkeys provide good models to study direct pituitary effects of various hormones or drugs.

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Section: Discussionsupporting

confidence: 68%

Section of the Pituitry Stalk in the Rhesus Monkey

et al. 1980

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“…This elevation is at variance with the normal fasting HGH levels in patients with diabetes mellitus recorded by several investigators (3,(41)(42)(43). In most of the reports, however, the heterogeneity of the diabetic and contrast groups and the circumstances of the study which might affect the plasma HGH concentration are not defined (8,9,32,33,44 46).…”

Section: Discussionmentioning

confidence: 71%

Metabolic clearance and production rates of human growth hormone

Taylor¹,

Finster²,

Mintz³

1969

J. Clin. Invest.

115

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A B S T R A C T The metabolic clearance rate (MCR) of human growth hormone (HGH) was determined by the constant infusion to equilibrium technique utilizing HGH-5I. 22 control subjects had a MCR of 229 ±52 ml/min (mean ±sD). No difference was evident between sexes, or between various age groups. Patients with acromegaly demonstrated normal MCR's. Moreover, acute elevations of plasma growth hormone concentrations in normal subjects did not alter the MCR of HGH. The MCR was relatively constant from day to day and within the day when subjects were evaluated in the supine position. In contrast, the assumption of the upright position was associated with a mean 24% decrease in the MCR.These results were contrasted with the MCR of HGH observed in a small number of patients with altered thyroid function or diabetes mellitus. In six patients with hypothyroidism the MCR (131 ±36 ml/min) was significantly decreased (P < 0.001); whereas the MCR in eight patients with hyperthyroidism (240 ±57 ml/min) did not differ from control subjects. The MCR in eight patients with insulin-independent diabetes mellitus (IID) (185 ±41 ml/min) and in eight patients with insulin-dependent diabetes mellitus (IDD) (136 ±31 ml/min) were significantly different from control subjects (P = < 0.05 and P = < 0.001, respectively).These data were interpreted to indicate that the plasma HGH-removing mechanism(s) is not saturated at physiologic plasma HGH of clearance from the plasma, and that the estimation of the MCR of HGH may help clarify the mechanism of abnormal plasma HGH responses to various stimuli.Production rates of HGH (PR) in control subjects (347 ±173 mug/min) were contrasted with hyperthyroid patients (529 ±242 mitg/min, P < 0.05), hypothyroid patients (160 ±69 m/g/min, P < 0.02), lID (245 ±100 m/g/min, NS), and IDD (363 ±153 mug/min, NS). Considerable variability in the determination of the concentrations of immunoprecipitable HGH-l`I and endogenous plasma HGH concentrations was encountered at apparent equilibrium conditions. Since both factors are necessary for the PR calculations, the wide 95% confidence limits of the PR's did not permit a clear interpretation of the significance of these observations. INTRODUCTION Investigators examining the physiologic regulation of plasma human growth hormone (HGH) have been aware that diverse stimuli (1-9) elicit changes in plasma HGH concentrations. Such changes in plasma levels alone, moreover, do not distinguish between the separate contributions of pituitary HGH release and HGH clearance from the plasma, both of which are responsible for a change in plasma concentration.The plasma disappearance of single intravenous injections of radioisotopically labeled HGH has been analyzed to define the distribution and turnover of HGH in humans (10-12). The fractional turnover and production rates of HGH in these studies were derived from calculations which assume first order kinetics and steadystate conditions. Some of the radioisotopic plasma disappearance curves in the literature (10, 11), however, do ...

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“…It was shown by Glick and coworkers (21) and later others (137, 138) using radioimmunoassay, that section of the pituitary stalk in the human prevented GH release in response to hypoglycemia and inhibition of GH secretion following glucose administration, although the response to hypoglycemia is maintained in certain individuals (138). Neoplastic or inflammatory lesions of the hypothalamus and pituitary stalk also produce GH failure (13, 74, 139, 140) and a blunted GH response to arginine has been described in cerebral dwarfs with mental and growth retardation associated with defective release of ACTH and GH (141).…”

Section: Evidence For Neural Control Of Growth Hormone Secretionmentioning

confidence: 98%

Psychologic and Neural Regulation of Growth Hormone Secretion

Brown

Reichlin

1972

Psychosomatic Medicine

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A wide variety of stressful stimuli, both physical and psychologic, cause GH discharge in both man and monkey in a manner reminiscent of the changes in ACTH secretion under similar circumstances. The hypothalamus appears to mediate acute changes in GH release as evidenced by the finding that basal hypothalamic or infundibular lesions and pituitary stalk section blocked the acute GH response to hypoglycemia in rat, monkey and man. Changes in GH release in hypoglycemia, prolonged fasting and exercise after meals are related to caloric homeostasis. GH elevation, after stressful stimuli, may produce metabolic effects related to caloric requirements and has protective effects on tissues. The mechanisms for growth hormone release and adrenal corticoid activation are independent since dissociation of these two responses is found after a variety of stimuli in man and monkey. Growth hormone and adrenal discharge appear to have specific independent psychologic correlates.With the development of the sensitive radioimmunoassay for growth hormone (GH) in human plasma (1-5), detailed experimental studies on growth hormone regulation became possible for the first time (6). A number of findings based on preimmunoassay data (7-9) were confirmed, such as blockade of growth hormone release by hypothalamic lesions and increased release of GH in starvation. In a few instances, previous inferences were not validated. Whereas it had been assumed that

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Growth Hormone in Relation to Diabetic Retinopathy

Cited by 59 publications

References 17 publications

Section of the Pituitry Stalk in the Rhesus Monkey

Section of the Pituitry Stalk in the Rhesus Monkey

Metabolic clearance and production rates of human growth hormone

Psychologic and Neural Regulation of Growth Hormone Secretion

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