Reproduction, physiological processes

Among vertebrate species, the neuro-endocrine-immime system is responsible for many complex, inter-related physiological processes including neuronal, homeostatic, reproductive and immune functions. There are four main types of hormone polypeptides, eicosanoids, steroids and thyroid hormones. Reflecting the inter-dependency of the neiiro-endocrine and immune systems, hormones, neuropeptides and other neiirotransmitters are known to be produced by some immune cells and play a role in the regulation of the immune system, while endocrine and nervous tissues express receptors for many substances produced by the immune system. The major focus of interest in endocrine disruption has... 

The egg and reproductive system thus present an elegant model for the study of a number of areas of physiological interest, especially the ultrastructure and cytochemistry of the spermatozoa, ova and embryonic envelopes (see p. 166), as well as the physiological processes involved in egg hatching and the subsequent activation of the released oncosphere. 

For the purposes of this chapter, reproductive toxicity will refer to any manifestations of xenobiotic exposure, including endocrine disruption (see discussion below), reflecting adverse effects on any of the physiological processes and associated behaviors and/or anatomical structures involved in animal reproduction or development (Figure 36.1). This is a fairly broad definition which encompasses developmental toxicity, as well as any toxic... 

Reproduction studies have to be extensive because of the diversity of physiological processes that may be affected, and because the consequences of error in this field are potentially horrific. Tests include... 

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