Plasma Growth Hormone in Men and Women over 70 Years of Age

Laron, Zvi; Doron, M.; Amikam, B.

doi:10.1159/000387283

Cited by 8 publications

(6 citation statements)

References 0 publications

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“…This finding augments past reports that GH responsiveness to other provocative stimuli also declines with age (8,14,15). Immunostaining techniques have revealed a significant decrease in both the size and number of GH-secreting pituitary cells from youth to middle age (29).…”

Section: Discussionsupporting

confidence: 87%

“…The results of several previous studies on the effects of aging on GH secretion have lead to disparate conclusions (7)(8)(9)(10)(11)(12)(13)(14)(15). The disagreement between the reports may have been due to differing techniques for assessing GH secretion and interpretation with respect to age.…”

Section: Discussionmentioning

confidence: 99%

“…Thus, a number of pharmacological stimulation tests have evolved to assess the normalcy of GH secretion (5,6). Previous studies of the effect of age on GH secretion relied on GH levels from single basal specimens (7)(8)(9) or from multiple samples drawn during short periods of the day (10)(11)(12) or after stimulation (7)(8)(9)(13)(14)(15).…”

mentioning

confidence: 99%

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The Influence of Age on the 24-Hour Integrated Concentration of Growth Hormone in Normal Individuals*

Zadik

McCarter

et al. 1985

The Journal of Clinical Endocrinology & Metabolism

611

225

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We examined changes in spontaneously secreted growth hormone with aging by studying the 24-h integrated concentration of GH (IC-GH) of 173 nonobese subjects (height, greater than or equal to 5%; 7-65 yr of age). There was no significant difference in IC-GH on repeat testing of 13 men or in 23 women studied in the follicular and again in the luteal phase of the menstrual cycle. The level of IC-GH was strongly effected by age; children had the highest mean IC-GH, and there was a decline in IC-GH with increasing age after the second decade of life. The correlation of IC-GH with age was highly significant (r = 0.73; P less than 0.0001). There was no difference in IC-GH between males and females when matched for age. The mean IC-GH at Tanner stage 5 of puberty (7.4 +/- 2.0 ng/ml) was higher than that at stages 2-4 (5.7 +/- 1.4; P less than 0.0005) or that in prepubertal children (5.8 +/- 1.4; P less than 0.001). Thus, age and pubertal status must be carefully considered when interpreting the IC-GH for patients suspected of having deficient or excessive secretion of GH.

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Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

The Influence of Age on the 24-Hour Integrated Concentration of Growth Hormone in Normal Individuals*

Zadik

McCarter

et al. 1985

The Journal of Clinical Endocrinology & Metabolism

611

225

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“…Both dopamine and norepinephrine and their agonists have been shown to elevate blood GH levels in rats [5,16,18,19,22], and may act to inhibit somatostatin or to promote GHRF release from the hypothalamus. Previous data in hu mans also indicated that the capacity to increase plasma GH after arginine infusion or insulin-induced hypoglyce mia diminished with age [1,4,13]. Therefore, it appears that the capacity to release GH may be impaired in aging rats and human subjects.…”

Section: Discussionmentioning

confidence: 98%

Effects of CNS Active Drugs and Somatostatin Antiserum on Growth Hormone Release in Young and Old Male Rats

et al. 1981

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The capacity of several potent pharmacological agents to increase growth hormone (GH) release was tested in young (3- to 4-month-old) and old (18- to 20-month-old) male Sprague-Dawley rats. Young and old animals were injected with α-methyl-p-tyrosine (250 mg/kg), a catecholamine synthesis inhibitor, followed 60 min later by the α-adrenergic receptor agonist, clonidine hydrochloride (150 μg/kg). Plasma GH levels increased to greater than 276 ng/ml by 30 and 50 min in young rats, whereas values never exceeded 130 ng/ml (p < 0.01) in old rats. Piribedil methane sulfonate (1 mg/ kg), a dopamine receptor agonist, significantly increased GH in young animals 60 min after injection (p < 0.05), but had no effect in old rats. Morphine sulfate (5 mg/kg) increased plasma GH concentrations in young rats to greater than 400 ng/ml at 30, 50 and 70 min after injection, whereas values in old animals never exceeded 300 ng/ml (p < 0.01). 15 min after injection of somatostatin antiserum No. 774 (5 ml/kg), plasma GH levels increased to greater than 750 ng/ml in both young and old rats. Administration of greater volumes of somatostatin antiserum (8 ml/kg) increased GH levels more in old than in young animals 30 and 45 min after injection (p < 0.01). These results indicate that old male rats have less capacity to increase GH in response to agents that normally enhance GH release. This may be the result of a diminished number or affinity of post-synaptic neurotransmitter receptors, or to an increased release of somatostatin. Since somatostatin antiserum increased GH equally or to a greater extent in old than in young animals, aging rats may release more somatostatin or the pituitary may be more sensitive to the inhibitory effects of this hormone.

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“…In the elderly, mean base levels of growth hormone (GH) are higher in females than in males, as also noted in young people. There appears to be no decrease in the GH content of the pituitary in old age, but the response to stimulation of GH secretion is considerably diminished in both men and women (15). Hypothalamic extracts which have potent GH‐releasing activity in young animals produce only minimal responses in the senescent rat (16).…”

Section: Hypothalamus‐pituitary Relationshipsmentioning

confidence: 99%

Role of the Hypothalamus in the Aging Woman*

Greenblatt

Natrajan

Tzingounis

1979

J American Geriatrics Society

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Relationships between the hypothalamus and the pituitary in the aging woman are discussed under the following subheadings: synthesis and release of follicle-stimulating and luteinizing hormones, estrogen receptors, other releasing factors, neurotransmitters, and the mechanisms of hot flushes and migrainoid headaches. The hypothalamus is the main regulator of pituitary function. In the female the hypothalamic-pituitary axis appears to remain functionally intact well into old age.

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Plasma Growth Hormone in Men and Women over 70 Years of Age

Cited by 8 publications

References 0 publications

The Influence of Age on the 24-Hour Integrated Concentration of Growth Hormone in Normal Individuals*

The Influence of Age on the 24-Hour Integrated Concentration of Growth Hormone in Normal Individuals*

Effects of CNS Active Drugs and Somatostatin Antiserum on Growth Hormone Release in Young and Old Male Rats

Role of the Hypothalamus in the Aging Woman*

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