Er der nogen der har den originale artikel de refererer til? Jeg kan ikke finde den... Kunne godt tænke mig at læse en forklaring på det han siger med at "skade udviklingen af de celler der danner testosteron". Han må mene at cannabis beskadiger Leydig's celler, men jeg har ikke set noget evidens for at det rent faktisk sker i virkeligheden.
Citat:
The dopaminergic and serotonergic fibers seem to be particularly important. The two gonadotropins, LH and FSH, secreted by the pituitary gland are of major importance to reproduction in the male. Both gonadotropins appear to respond to a single releasing factor from the hypothalamus, GnRH, which is sensitive to catecholamine neurotransmitters. The THC-induced block of GnRH release results in lowered LH and FSH which is responsible for reduced testosterone production by the Leydig cells of the testis.
NIDA Res Monogr. 1984;44:46-64.og
Citat:
In mice, chronic administration of crude marihuana extract (CME), delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN) (50 mg kg-1 body weight for 15 and 35 days) impaired spermatogenesis at both mitotic and meiotic stages. Although the total number of step 7 spermatids was unaltered, mature spermatozoa recovered from the cauda epididymidis showed severe abnormalities in morphology. Body weight and sex organ weights were not affected markedly but the adrenal gland was hypertrophied. Leydig cell nuclear area was increased by CME and CBD and reduced by CBN. Cannabis deranges several stages of the spermatogenic cycle, most of the activity of the crude extract being attributable to CBN and CBD.
Andrologia. 1991 Mar-Apr;23(2):151-6.
Men de niveauer der skal til for rent faktisk at inducere de ændringer er meget høje, og når man kigger på in vivo data fra mennesker ser det anderledes ud:
Citat:
The object of this study was to establish possible influences of long-term cannabis usage on plasma testosterone levels. The plasma testosterone levels of 66 male Pakistani who for years had smoked cannabis daily or drank cannabis regularly where measured after chronic and acute intake of the drug and compared with a material of 41 normal controls, i.e. persons who did not use cannabis. An evaluation of the results showed that there were no significant differences between the two groups. No influence of long-term cannabis usage on plasma testosterone levels was found. Furthermore we wished to find out wether long-term heroin abuse showed an effect on plasma testosterone levels. The concentrations of testosterone in the plasma of 102 heroin addicts assigned to a Methadone Program were measured and compared with the values of 29 male healthy students as controls. Plasma testosterone levels were found to be significantly decreased in heroin addicts as compared to controls.
Beitr Gerichtl Med. 1990;48:57-66.