Also see:
Inflammatory TSH
Growth Hormone and Edema
“Normal” TSH: Marker for Increased Risk of Fatal Coronary Heart Disease
W.D. Denckla, A.V. Everitt, Hypophysectomy, & Aging
Quotes by Ray Peat, PhD:
“On the level of the whole organism, stress causes overactivity of the pituitary, and removal of the pituitary extends life, and retards the hardening of the extracellular connective material (Everitt, et al., 1983).”
“Several of his [Everett] experiments strongly pointed to the prolactin-growth hormone family as the aging factors. Removal of the pituitary caused retardation of aging similar to food restriction.”
“The “little mouse,” and the experiments of Denckla and Everitt, show that a simple growth hormone deficiency or lack of pituitary function can double the life span: Intervention in the many other self-stimulating excitatory pathways can produce additional retardation of the aging process, acting at many levels, from from the extracellular matrix to the brain.”
“Several groups (Powers, et al., 2006; Everitt, et al., 1980; Telford, et al., 1986) have shown that removal of the pituitary gland can greatly extend lifespan, if thyroid hormone is supplemented.”
Mech Ageing Dev. 1983 Jul-Aug;22(3-4):233-51.
The anti-aging action of hypophysectomy in hypothalamic obese rats: effects on collagen aging, age-associated proteinuria development and renal histopathology.
Everitt AV, Wyndham JR, Barnard DL.
Hypophysectomy in young male Wistar rats aged 70 days, like food restriction begun at the same age, retarded the life-long rate of collagen aging in tail tendon fibres and inhibited the development of age-associated proteinuria and renal histopathology. Hypothalamic lesions which increased the food intake of hypophysectomized rats from 7 g to 15 g/day and produced obesity did not alter the rate of either collagen aging or proteinuria development, nor reduce life expectancy, but increased the incidence of abnormal glomeruli. In the intact rats elevation of food intake from 7 g to 15 g/day increased the rate of proteinuria development, but did not affect the rate of collagen aging. Hypophysectomy was found to have a greater anti-collagen aging effect than food restriction, when food intakes were the same in both groups. These studies suggest a pituitary-hormonal effect on collagen aging and a food-pituitary-hormone-mediated effect on the development of age-associated proteinuria.
Biogerontology. 2003;4(1):47-50.
Food restriction, pituitary hormones and ageing.
Everitt AV
Reducing the intake of food in rodents inhibits body growth, retards most physiological ageing processes, delays the onset of pathology and prolongs life. Food restriction (FR) reduces pituitary hormone secretion and in consequence has been called ‘functional hypophysectomy’. Direct life-long comparisons in the rat showed that hypophysectomy (HYP) (a complete absence of pituitary hormones) has a greater anti-ageing action than FR (a partial lack of pituitary hormones) on collagen, kidney and muscle. This suggests that pituitary hormones accelerate ageing. Recent American research on genetic variants of the mouse indicates that pituitary growth hormone (GH) may accelerate ageing and shorten life. Both the Snell and Ames dwarf mice have a deficiency of pituitary GH and live 50% longer than normal mice. The Snell dwarf mouse has retarded ageing of both collagen and immune functions. The Ames dwarf mouse has high antioxidant enzyme activities in liver and kidney. A transgenic human GH mouse is short lived, has a low activity of antioxidant enzymes in liver and kidney and an early development of disease in these organs. It is postulated that FR by reducing the secretion of pituitary hormones, such as GH, diminishes the oxidative damage of certain tissues, thereby delaying the development of age-related diseases in these tissues and by this means extends life.
Mech Ageing Dev. 2006 Aug;127(8):658-9. Epub 2006 Apr 27.
Pituitary removal in adult mice increases life span.
Powers RW 3rd1, Harrison DE, Flurkey K.
Dwarf mutations reduce levels of pituitary hormones and increase life span in mice. But because these dwarf mutations confer life-long hormone deficits that alter development and dramatically reduce fecundity, the relevance of these models to normal aging has been questioned. We examined effects of pituitary hormone withdrawal at different ages using hypophysectomy (surgical removal of the pituitary). Hypophysectomy at 1 month of age extended life span significantly (15%), but hypophysectomy at 9 months of age extended life span to the greatest magnitude (21%) of any age we tested. These results demonstrate pituitary hormone withdrawal can extend life span even if these hormones are removed relatively late in life.
Neuroendocrinology. 1986;43(2):135-42.
The increase of anterior pituitary dopamine in aging C57BL/6J female mice is caused by ovarian steroids, not intrinsic pituitary aging.
Telford N, Mobbs CV, Sinha YN, Finch CE.
We describe how the increase of anterior pituitary dopamine (DA) during aging in female mice is related to altered secretion of ovarian steroids during reproductive senescence. A number of age-correlated neuroendocrine changes in female rodents result from cumulative exposure to ovarian steroids over a lifetime of estrous cycles, or from the altered pattern of ovarian steroid secretion concomitant with reproductive senescence. Pituitary DA has been shown to increase with age in female rats. To examine how the age-correlated increase of pituitary DA may depend on estradiol (E2), we measured pituitary DA and serum prolactin (PRL) in the following groups of female mice: young (7 months) cycling, middle-aged (14 months) cycling and non-cycling, old (17 months) non-cycling, old (17 months) ovariectomized (OVX) at 4 months, and young mice given 0.2 mg E2 valerate or E2 implants. Mice from some of these groups were OVX 1, 4 or 8 weeks before sacrifice. Compared with young controls, 14-month-old cycling or non-cycling mice had 3-fold higher pituitary DA, and 17-month-old non-cycling mice had 5-fold higher pituitary DA. OVX for 2 or 13 months before sacrifice abolished the effect of age; OVX of young mice had no effect on pituitary DA. Three weeks after implantation of E2 into OVX young mice or 7 weeks after injection of E2 valerate in intact young mice, pituitary DA was elevated. The E2-sensitive fraction of pituitary DA does not appear to decrease PRL secretion.(ABSTRACT TRUNCATED AT 250 WORDS)
