Testes

The purification procedure for the pig testis non-heme iron protein has been published elsewhere (28, 43). The procedure is similar to Procedure B . The isolation of testis mitochondrial fraction, Procedure A , is not recommended due to the low yield of the mitochondria and loss of the non-heme iron protein. The yield of the non-heme iron protein from testis was very much lower than the yield of adrenodoxin from adrenal cortex. This may indicate that testis hydroxylation is less active than adrenal hydroxylation. 

The testicular production of free radicals and the function of the antioxidative defence system have a role in infertility caused by defective sperm func- 

Cadmium-induced acute testicular toxicity and testicular interstitial cell tumours in rats cmild be prevented by low-dose Cd (3.0 juM/kg subcutaneously) pre-treatment (Wahba et al. 1990). 

Parenteral administration of nickel chloride (NiCh) to rats enhanced hpid peroxidation in liver, kidney and lung, but not in brain, heart, spleen or testis, as measured by the thiobarbituric acid reaction for malondialdehyde and related chromogens in fresh tissue homogenates (Sunderman etal. 1985). 

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Mucopolysaccharide levels are increased in many cancer cells this increase is accompanied by a decreased vascular supply. Hyaluronidase [9001-54-17, obtained from bovine testis, dissolves the mucopolysaccharides surrounding a tumor, thereby allowing cytotoxic agents to penetrate the neoplasm with enhanced faciUty. In clinical studies hyaluronidase was given to patients with malignant tumors, alone or in combination with 5- uorouracil [51-21-8], significant decreases in tumormass were observed (55). 

As regards toxicity, pyrazole itself induced hyperplasia of the thyroid, hepatomegaly, atrophy of the testis, anemia and bone marrow depression in rats and mice (72E1198). The 4-methyl derivative is well tolerated and may be more useful than pyrazole for pharmacological and metabolic studies of inhibition of ethanol metabolism. It has been shown (79MI40404) that administration of pyrazole or ethanol to rats had only moderate effects on the liver, but combined treatment resulted in severe hepatotoxic effects with liver necrosis. The fact that pyrazole strongly intensified the toxic effects of ethanol is due to inhibition of the enzymes involved in alcohol oxidation (Section 4.04.4.1.1). 

Recent studies suggest that mercury can cause an instant decrease in the sperm viability of fish at concentrations comparable to those which are permitted in drinking water (1 /rg C ). The bioconcentration of the metal to levels in the testis considerably higher than this from water containing only 1/30 of permitted levels" suggests that current legal limits are much too high. 

Female sexual development and behaviour in mammals occurs by default and requires no ovarian secretion, and it is only in genetic males that the testis can secrete hormones which destroy this female pattern and superimpose that of the male. Sexual differentiation is not so well defined in fish, and larval exposure to both synthetic estrogens and androgens is widely used in aquaculture to produce monosex cultures. Endocrine disruption of sexual differentiation in fish may therefore reflect both the complexity and diversity of such processes between different species. Some care is required in use of the terms hermaphrodite and sex-reversal since a true hermaphrodite has both functional testes and ovaries and a sex-reversed fish is fully functional as its final sex—both produce the appropriate viable gametes. Such functional sex-reversal is not possible in mammals, but in some species of fish it is the normal developmental pattern. In most of the cases of hermaphroditism or sex-reversal reported in the non-scientific press, there is evidence only for a few ovarian follicles within a functional testis. This may be considered as feminisation or a form of intersex, and is very clearly endocrine disruption, but it is certainly neither sex-reversal nor hermaphroditism. In some cases the terms have even been used to infer induction of a single female characteristic such as production of yolk-protein by males. 

However, incidence of testicular cancer is increasing in American blacks and Japansese, both of whom have a low incidence of testis cancer. " Extrapolation of the epidemiological trends suggests that the incidence rate of testis cancer will continue to double every 15-25 years. 

It is widely accepted that men with testicular cancer have a higher incidence of abnormalities associated with impaired spermatogenesis, both in the cancerous testis but also in the contralateral testis. Men diagnosed as having testicular cancer often have very poor semen quality, with sperm concentrations of less than 10 million/ml compared to healthy men with > 50 million/ml." It is thought that gonadal function is abnormal even before testicular cancer develops, ... 

Figure 1 The major hormones involved in growth and funetion of the fetal/neonatal testis illustrating how exogenous, environmental oestrogens eould disrupt the normal balanee of these meehanisms.

Table 1 Sites of androgen and oestrogen reeeptors and aromatase aetivity in the testis and assoeiated duets during fetal/perinatal life in the rat ...

The presence of aromatase in the testis and in sperm further emphasises the likelihood that the local production of oestradiol within the male reproductive... 

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