Effects of subchronic ifosfamide-mesna treatment on testes and semen characteristics in the rabbit

Alkylating agents-induced gonadotoxicity in prepubertal males: Insights on the clinical and preclinical front

Rising cure rates in pediatric cancer patients warrants an increased attention toward the long-term consequences of the diagnosis and treatment in survivors. Chemotherapeutic agents can be gonadotoxic, rendering them at risk for infertility post-survival. While semen cryopreservation is an option that can be provided for most (post)pubertal boys before treatment, this is unfortunately not an option prepubertal in age, simply due to the lack of spermatogenesis. Over the last couple of years, studies have thus focused on better understanding the testis niche in response to various chemotherapeutic agents that are commonly administered and their direct and indirect impact on the germ cell populations. These are generally compounds that have a high risk of infertility and have been classified into risk categories in curated fertility guidelines. However, with it comes the lack of evidence and the challenge of using informative models and conditions most reflective of the physiological scenario, in short, the appropriate study designs for clinically relevant outcomes. Besides, the exact mechanism(s) of action for many of these "risk" compounds as well as other agents is unclear. Understanding their behavior and effect on the testis niche will pave the way for incorporating new strategies to ultimately combat infertility. Of the various drug classes, alkylating agents pose the highest risk of gonadotoxicity as per previously established studies as well as risk stratification guidelines. Therefore, this review will summarize the findings in the field of male fertility concerning gonadotoxicity of akylating agents as a result of chemotherapy exposure.

Observations on Dag-like defect of spermatozoa induced by treatment of the phytotherapeutic Quassia amara/quassin in the mouse model

Gross alterations in the morphology of spermatozoa, teratozoospermia, invariably render them incapable of fertilisation. One of the contributory factors to teratozoospermia is failure of spermatozoon to shed the cytoplasmic droplet even after their arrival at epididymis. Quassia amara and quassin are of medicinal value with special reference to malaria. Nevertheless, there are also reports implicating Quassia/quassin in male reproductive toxicity. We were interested in finding if its therapeutic application would jeopardise male fertility. So, we tested it for male reproductive toxicity by analysing, among other aspects, abnormal sperm morphologies, and made a systematic analysis of the spermatozoa of treated mice before they are spermiated and until they arrive at the cauda epididymis. The spermatozoa not only failed to shed the cytoplasmic droplet during epididymal transit but swell to a very large size and were angulated, resulting in Dag-like defect or lasso shape. A link between cytoplasmic droplet that was retained and lasso shape of tail was indicated. This article traces the structural changes in spermatozoa that lead to angulation, flexion and coiling of the tail, caused due to retention of cytoplasmic droplet, and explains one of the mechanisms of toxicant-induced teratozoospermia.

Dose related effects of ifosfamide on enterocyte apoptosis in different sites of the rabbit intestine

OBJECTIVE

We investigated the potential dose related apoptotic effect of subchronic administration of the alkylating chemotherapeutic agent ifosfamide in different sites of the small and large rabbit intestine.

MATERIALS AND METHODS

Twenty New Zealand White rabbits received intravenously every week, for 10 weeks, 0 (group S, controls, n = 5), 30 (group A, n = 5), 45 (group B, n = 5) or 60 mg/kg ifosfamide (group C, n = 5). One day after the end of the treatment period, segments of jejunum, ileum, cecum, proximal and distal colon were excised. Intestinal mucosa apoptosis was detected by agarose gel electrophoresis and quantified by DNA fragmentation and standard terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-biotin nick-end labelling (TUNEL) assays by which the percentage of fragmented DNA and the ratio of apoptotic cells per crypt (apoptotic index) were determined, respectively.

RESULTS

At low dose (group A), ifosfamide had minor apoptotic effect on enterocytes, which was enhanced mainly in the small intestine when the dose was increased (group B); at the highest dose tested (group C), this effect was extended to the large intestine. In all groups of animals, the observed crypt cell apoptosis was maximal in the ileum, while minimal in the proximal colon.

CONCLUSIONS

Our results show a dose and intestinal site-dependent induction of enterocyte apoptosis after subchronic ifosfamide administration in the rabbit.