Previous work from our laboratory prompted us to study the effects of short-term, acute administration of TRH or its chronic oral administration, on organs, tissues and aging-related metabolic and hormonal markers, in order to acquire more knowledge on effects, dosage and timing of administration according to its circadian cyclicity. In addition, we wanted to verify its antiaging effects on two most fundamental functions, namely gonadal- reproductive and kidney-urinary.
The results demonstrate that short-term, acute, or a chronic, long-term oral administration of TRH to old, aging mice, results into positive changes and rapid correction to more juvenile levels of most typical age-related hormonal, hematologic and metabolic alterations.
Remarkably, 4-month oral treatment with TRH maintains testes function in aging mice. As hinted by the significant increase of testes weight, TRH taken from the drinking water produces a maintenance and/or reconstitution of testes structure and function as shown by active proliferation and formation of mature spermatogonia and intensive spermatogenesis in the follicles. 4-month oral treatment with TRH protects the kidneys from amyloid and hyalin infiltration of both tubuli and glomeruli, which is typical of aging mice. In fact, massive deposits of amyloid and hyalin material are clearly infiltrating the shrunken glomeruli of untreated mice with loss of filtration capacity, while hardly present in TRH-treated mice. Massive hyalin degeneration can also be observed in the tubular vessels of the untreated control mice.
These experiments with intraperitoneal and oral administration of TRH show a most remarkable age-delaying and apparently even age-reversing effect of the neuropeptide TRH. Again, similarly to melatonin, we are confronted with an antiaging agent with a broad spectrum of activities which must be necessarily linked to a most fundamental role in the regulation of metabolic and hormonal functions.
From the Fifth Stromboli Conference on Aging and Cancer, June 2010, Current Aging Sciences, Bentham, 2012, in press.