Enzyme changes in the gerbil testis produced by the administration of an alkylating agent 'Busulphan' (Myleran, 1,4 dimethanesulphonoxybutane)

Histophysiological changes of the testicular tissue due to busulphan administration in the wild Indian house rat (Rattus rattus)

The results of the present study indicate the antispermatogenic activity of Busulphan or Myleran (1,4-dimethane-sulphonoxy butane) on the testicular tissue of adult male Indian house rat, Rattus rattus. Single oral dose of Busulphan (10 mg/Kg body weight) was administered and its activity was noticed at 10, 40, 70 and 100 days of posttreated animals. Histological observation and quantitative histological study indicates no major alteration in the relative percentages of primary spermatocytes, spermatid and Sertoli cells at 10 days of posttreatment. But there was a gradual decrease in the seminiferous tubular diameter at 40 and 70 days of post treated groups. However, the Leydig and Sertoli cells morphology and number remained normal in all the treatment groups. At 40 days, the normal cellular associations in all the tubules were disrupted. The tubules constituted only spermatogonia, Sertoli cells and some zygotene spermatocytes. At 70 days, repopulation of Type A, Type B spermatogonia, resting and zygotene spermatocytes occurred at this stage. The tubules were still devoid of pachytene spermatocytes, spermatid and spermatozoa. At 100 days, active spermatogenesis was observed in majority of the tubules. The various types of germ cell population were regaining towards normalcy. Histochemical studies clearly revealed that due to busulphan administration there was no major alteration in the intensities of some key enzymes (i.e. delta5 3beta-HSDH and 17beta-HSDH) involved in the biosynthesis of steroid hormones. Only the acid phosphatase activity was slightly depressed within the 40th and 70th days of posttreatment. Sudanophilic lipid materials increased in the interstitium of all the busulphan post treated groups. The changes which were noticed due to busulphan treatment regained normalcy at 100 days of post treated animals. The mode of action of Busulphan on the testicular tissue of adult Indian house rat (Rattus rattus) has been pointed out and discussed.

Toxicological review of busulfan (Myleran)

Busulfan is a bifunctional alkylating agent that appears to be cytotoxic to slowly proliferating or non-proliferating stem cell compartments, although its specific molecular and cellular mechanisms are unknown. It is the drug of preference in treatment of chronic myelogenous or granulocytic leukemia because its cytotoxic activity results in primary damage or destruction of hematopoietic cells. Additional effects resulting from the cytotoxicity of busulfan in hematological and other tissues, as documented by both human and animal model studies, include lethality, sterility, teratogenicity, and alteration of immune function. Busulfan has been shown to be mutagenic to microorganisms, mammalian cells in culture, Drosophila, and rodents. This agent is also considered potentially carcinogenic to humans. Various tissue hyperplasia and preneoplastic cells have been observed in animal model studies with busulfan, and case reports on human patients implicate busulfan as the causative agent in induction of secondary malignancies. Reports from human and animal studies of busulfan's cytotoxicity, teratogenicity, carcinogenicity, and mutagenicity have been reviewed. This information may be useful in a quantitative assessment of the effects of this agent and the identification of significant deficiencies in the data base. Demonstration that busulfan induces mutations in both somatic and germ cells suggests the need to assess its risk to humans.

Studies on the mechanism of action of alpha-monochlorohydrin

After a single oral dose of 100 mg/kg of alpha-chlorohydrine, two distinct phases in the response of the testes to the treatment have been observed: (i) the immediate onset of testicular swelling lasting up to five days, accompanied with a steady increase in the weight of the testes and (ii) thereafter a constant decrease in the testes weight. Changes in the diameter of the seminiferous tubules and the thickness of the basement membrane were observed after the administration of the drug. Multinucleated giant cells were encountered 5 days after drug administration. Alkaline phosphatase, SDH, nucleic acids and proteins showed a fall after treatment with the drug. On the contrary, cholesterol, phospholipids and glycogen showed an increase after its administration. Acid phosphatase showed a fall in the initial stages only, but the activity was higher after 10, 20 and 40 days of the treatment with the drug. The level of plasma and testes testosterone remained normal after chlorohydrin administration. The induction of lesions in hypophysectomised gonadotropin-stimulated animals suggests that the action of chlorohydrin is not mediated through gonadotropins. Alpha-chlorohydrin administered intratesticularly did not evoke any changes in the histo-architecture of the testis.