A recent article claims that the use of viagra (sildenafil) reduces the clinical signs of EAE in mice [experimental autoallergiuc encephalitis – a lab animal virus believed to be simiar to MS virus] by preventing axonal loss and promoting remyelination … AHA!
Drug companies have been looking for an excuse to market Viagra to women. Since it is believed more women than men have multiple sclerosis this article might fool some people into thinking that Viagra would help repair of myelin in humans!
Just one problem – for the past 40 years or so, the repair of myelin in laboratory animals has been proven to occur naturally in a week or so. SO – “researchers” would have had the same results with soda crackers. Reminds me of the carnival game of switching walnut shells to find the one with the pea under it!
So what’s up?
HERE IS THE ARTICLE!
Pifarre P, Prado J, Baltrons MA, Giralt M, Gabarro P, Feinstein DL, Hidalgo J, Garcia A.
Sildenafil ameliorates clinical symptoms and neuropathology in a mouse model of multiple sclerosis. Acta Neuropathol. 2011 Apr;121(4):499-508. doi: 10.1007/s00401-010-0795-6. Epub 2011 Jan 15. Institute of Biotechnology and Biomedicine, Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain.
Abstract
Cyclic GMP (cGMP)-mediated pathways regulate inflammatory responses in immune and CNS cells. Recently, cGMP phosphodiesterase inhibitors such as sildenafil(viagra), commonly used to treat sexual dysfunction in humans including multiple sclerosis (MS) patients, have been reported to be neuroprotective in animal models of stroke, Alzheimer’s disease, and focal brain lesion. In this work, we have examined if sildenafil ameliorates myelin oligodendrocyte glycoprotein peptide (MOG35?55)-induced experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. We show for the first time that treatment with sildenafil after disease onset markedly reduces the clinical signs of EAE by preventing axonal loss and promoting remyelination. … results highlight novel actions of sildenafil that may contribute to its beneficial effects in EAE and suggest that treatment with this widely used and well-tolerated drug may be a useful therapeutic intervention to ameliorate MS neuropathology.
NOTE: While lab animals recover, we humans continue to believe that we can expect progressive decline with little hope for recovery, and that we must wait for a chemical miracle … and few try to move.
REFERENCES proving repair of myelin in lab animals.
Hirano A, Levine S and Zimmerman HM (1968) Remyelination in the Central Nervous System after Cyanide Intoxication. J Neuropath Exp Neurol 27:234-245.
By one week after demyelination [in adult rats] we observed remyelination … recently several fine structural studies have established this phenomenon beyond reasonable doubt. p235
Raine CS and Bornstein MB (1970) EAE: A Light and Electron Microscopy Study of Remyelination and Sclerosis in Vitro. J Neuropath Exp Neurol 29:552.
... total demyelination in living mice embryo tissue cultures … tissue fragments began to remyelinate after 8 -10 days and process was well advanced by 18 days.
By three weeks, almost total remyelination.
NOTE: I wrote a letter to the Spanish group, as one of millions who count on research, expressing my dismay with twisting scientific research to satisfy pharmaceutical interests. I take such work as a personal insult.
With corroborating references, I shared the fact demyelination and majority of demyelinated fibres showed evidence of remyelination by 1month.
Although conduction would still be slow in the thinly myelinated fibres, the return of the ability to conduct at all is clearly a necessary first step in the recovery of function in damaged pathways. p301.