Long-term use of HU210 adversely affects spermatogenesis in rats by modulating the endocannabinoid system.

Recent societal acceptance of cannabinoids as recreational and therapeutic drugs has posed a potential hazard to male reproductive health. Mammals have a highly sophisticated endogenous cannabinoid (ECS) system that regulates male (and female) reproduction and exo-cannabinoids may influence it adversely. Therefore it is imperative to determine their effects on male reproduction so that men can make informed choices as to their use. Here, an animal model was used to administer HU210, a synthetic analogue of Δ9-tetrahydrocannabinol (THC) and potent cannabinoid receptor (CB) agonist to determine its effects on reproductive organ weights, spermatogenesis, testicular histology and sperm motility. Its effects on the physiological endocannabinoid system were also investigated. Spermatogenesis was markedly impaired with reductions in total sperm count after 2 weeks of exposure. Spermatogenic efficiency was depleted, and Sertoli cell number decreased as exposure time increased with seminiferous tubules showing germ cell depletion developing into atrophy in some cases. Sperm motility was also adversely affected with marked reductions from 2 weeks on. HU210 also acted on the sperm's endocannabinoid system. Long-term use of exo-cannabinoids has adverse effects on both spermatogenesis and sperm function. These findings highlight the urgent need for studies evaluating the fertility potential of male recreational drug users. HU210, a selective agonist for CB1 and CB2 cannabinoid receptors impairs spermatogenesis and sperm motility and deregulates the endocannabinoid system.

Molybdenum-associated pituitary endocrinopathy in sheep treated with ammonium tetrathiomolybdate.

Ammonium tetrathiomolybdate (TTM) has hitherto been the treatment of choice for chronic copper poisoning in sheep, but the long-term consequences have not been evaluated. This study was based on a flock of copper-poisoned sheep which, after apparently successful treatment with TTM, became infertile and progressively unthrifty and eventually died 2-3 years later. The last five surviving animals were subjected to euthanasia and detailed study. Necropsy revealed marked wasting together with depletion of the pituitary and adrenal glands, testicular atrophy and ovarian cystic follicles. Histopathological examination revealed a non-inflammatory atrophy or degeneration of the adenohypophysis with loss of trophic cells; adrenocortical and testicular atrophy and ovarian degeneration. The regressive changes in the anterior lobe of the pituitary were confirmed by immunocytochemical labelling, which revealed a marked depletion of adrenocorticotrophic hormone (ACTH), follicle stimulating hormone (FSH) and luteinizing hormone (LH) in the affected pituitaries by comparison with healthy controls. Excess molybdenum (Mo) retention (P<0.02) was identified by inductively coupled plasma mass spectrometry (ICPMS) in the pituitaries and atomic absorption spectrometry (AAS) in the adrenals and brains of affected sheep. It was concluded that molybdenum introduced systemically as TTM is retained within the brain, pituitary and adrenal glands and is associated with a toxic endocrinopathy. It is postulated that Mo administered as thiomolybdate adversely affects the hypothalamo-adenohypophyseal system by interfering with trophic hormone release, leading to the cessation of reproductive activity and ultimately the failure of intermediary metabolism. Whether Mo exerts its effect centrally or directly on the pituitary was not established.

Metallothionein expression in canine and feline mammary and melanotic tumours.

Moderate to strong immunohistochemical metallothionein (MT) positivity (MT expression) is associated with a poor prognosis in some human tumours. The aim of this study was to determine MT expression in mammary tumours and cutaneous melanomas in dogs and cats. Canine (67) and feline (47) mammary tumours, and cutaneous melanomas (canine 40, feline 26) were immunolabelled with MT monoclonal antibody E9. The overall incidence of MT expression of these tumours was similar to that observed in various human neoplasms. However, a striking interspecies difference was detected. In dogs, MT expression occurred in 100% of benign and 57% of malignant mammary tumours. In cats, however, 30% of malignant mammary tumours expressed MT but benign mammary tumours and cases of fibroadenomatous hyperplasia did not. Moderate to strong MT immunoreactivity was detected in 30% of benign and 25% of malignant cutaneous melanomas in dogs, and in 6% of malignant melanomas in cats. The findings in feline mammary tumours resembled findings reported in human breast cancer, but the cause of tumour-associated MT expression is unknown. Studies are in progress to determine whether the MT state (apo [metal-free] or holo [metal-bound]) accounts for the paradoxical association of MT expression with individual types of tumours and the animal species in which they arise.

Immunocytochemical detection of metallothionein (MT1 and MT2) in copper-enhanced sheep brains.

The role of metallothionein (MT) in the brain in heavy metal detoxification is relatively unexplored. Brain copper (Cu) elevation although unusual in chronic Cu poisoning in sheep, has been shown to occur after treatment with the chelating agent ammonium tetrathiomolybdate (TTM). The aim of this study was to investigate the expression of MT in TTM Cu-enhanced sheep brains, with immunohistochemical techniques. Brains from TTM-treated, Cu-poisoned sheep were examined for MT immunolabelling with a mouse monoclonal antibody (E9) for MT1 and MT2, and compared with brains from untreated sheep. Brain samples were analysed separately for Cu and zinc (Zn) by atomic absorption spectrophotometry. Markedly increased MT immunoreactivity was found in astrocytes of the cerebellum, thalamus/hypothalamus, cerebrum and medulla oblongata of the high-Cu brains, corresponding to the regional Cu elevations. MT immunolabelling was also found in the pia mater, choroid plexus and ependymal cells. Neurons were rarely labelled. MT induction within astrocytes and at the blood-brain barrier suggests that these are sites of stabilization and possibly transport for Cu and supports the hypothesis that the astrocyte compartment modulates metal homeostasis, conferring protection on vulnerable neurons and effecting damage limitation.

Metal (molybdenum, copper) accumulation and retention in brain, pituitary and other organs of ammonium tetrathiomolybdate-treated sheep.

Ammonium tetrathiomolybdate (TTM) is the treatment of choice for chronic Cu poisoning in sheep and is recommended in Wilson's disease. However, the long-term effects have not been fully evaluated and some evidence questions the long-term safety of the drug. The aim of the present study was to investigate the systemic distribution and retention of Cu and Mo in TTM-treated sheep of different breeds and Cu status. Low-Cu Cambridge sheep were divided into a TTM trial group (3.4 mg/kg, subcutaneously, on three alternate days per month, for 5 months) and a control group, and were killed at the end of the course or 7 months later. High-Cu sheep consisting of a Cu-supplemented (150 mg/kg) Cambridge group and a North Ronaldsay group were administered TTM as before and compared with untreated controls. Brain, liver, kidney, heart, skeletal muscle, pituitary, adrenals, tests and ovaries were retained for metal analysis. Mo accumulated in all organs including brain and pituitary (P < 0.02) in all TTM trial groups and was retained after cessation of treatment, except in liver, kidney and skeletal muscle. Cu was increased (P < 0.02) and retained in the cerebellum and medulla oblongata in the TTM-treated high-Cu Cambridge groups. Brain Cu v. Mo concentrations showed a strongly positive correlation (r. 0.7) in the high-Cu Ronaldsay group 7 months after TTM treatment. It is concluded that TTM is not all excreted but (Mo) is widely distributed and retained in many organs including brain and pituitary. In addition TTM may redistribute some displaced excess liver Cu (Cu-TTM) to the brain. The consequences of these disturbances await clarification.

An educational intervention on promotion of breast feeding complemented by continuing support.

The study, aiming to document the effect of continued support for mothers on frequency of exclusive breast feeding, was carried out by inclusion of breast feeding counselling in the context of well-baby care. One hundred and forty-six mothers who had been exposed to two educational sessions on breast feeding after delivery were given appointments to bring their baby to the paediatric hospital for well-baby care. The mother-infant pairs were followed by the same two residents for 4 months. Mean number of visits was six. A conscious effort was made during all visits to influence the mothers and their close relatives towards exclusive breast feeding. It was observed that in a large proportion of the infants, breast milk was being supplemented with water at the time of the first visit and no further effort was made to change this traditional behaviour. Comparison of the results with a group of mothers who had been exposed to similar educational sessions after delivery but without further support showed a striking increase in frequency of exclusive breast feeding (breast milk and water) in the supported group.

PIP: Researchers enrolled at least 96 primiparous women infant pairs in Instanbul, Turkey into a study intended to examine the effect of continued support of mothers on an educational model to promote exclusive breast feeding. Both the study group and the control group were exposed to the same educational sessions on breast feeding. The mothers received an appointment card during the 1st home visit for a follow up visit at the University Children's Hospital at 2 weeks. The same physician saw the same group of infants monthly for 4 months. The physicians discussed breast feeding and infant feeding with mother for 5-15 minutes. Further they encouraged mothers to telephone or visit whenever a problem occurred. They also suggested bringing a close family member with them, especially the mother in law. Indeed close relatives accompanied mothers on 90% of the visits. The deeply rooted tradition of supplementing breast milk with water manifested itself in 47.9% of the cases at 1 week. Since this was so deeply rooted, the researchers considered breast milk and water as exclusive breast feeding. 85.4% of the study group practiced exclusive breast feeding at 1 month compared to 60.9% for the control group. Even though the percentage of those in the study group who exclusively breast fed was lower at 4 months (60.9%), it was well above the comparable percentage for the control group (5%). Moreover by 4 months only 4.2% of case infants were completely weaned compared to 34.8% of the control infants. These results indicate that continuing support for mothers who breast feed plays an key role in promotion of breast feeding. Further it is preferable if the continuing support comes from the same health worker.