Of reproductive system

The animal database provides strong evidence that developmental toxicity is a sensitive end point following 2,3,7,8-TCDD exposure. Structural malformations, functional alterations (including impaired development of reproductive system), decreased growth, and fetal/newbom mortality have been observed in several animal species. Limited human data on the developmental toxicity of CDDs is available. Most of these studies examined the occurrence of birth defects in children of males exposed to 2,3,7,8-TCDD. Deficiencies in the human data preclude drawing firm conclusion on the potential of 2,3,7,8-TCDD to induce developmental effects in humans. However, the animal data suggest that 2,3,7,8-TCDD is a likely human developmental toxicant. 

Ema M, Miyawaki E, Kawashima K (2000) Critical period for adverse effects on development of reproductive system in male offspring of rats given di-n-butyl phthalate during late pregnancy. Toxicol Lett, 111 271-278. 

Follicle-stimulating hormone FSH Ovaries, testes Growth of reproductive system... 

Gonads Estrogens (estradiol) Maturation and function of reproductive system in females... 

PILLS Controls of Reproductive Systems by Hormones and Their Analogues... 

Exposure to excessive amounts of lead over a long period of time (chronic exposure) increases the risk of developing certain diseases. The parts of the body which may be affected include the blood, nervous system, digestive system, reproductive system, and kidneys. These effects include anemia, muscular weakness, kidney damage, and reproductive effects, such as reduced fertiHty in both men and women, and damage to the fetus of exposed pregnant women. 

In addition to the weU-defined opioid systems in the central nervous system, the three opioid peptides and their precursor mRNA have also been identified in peripheral tissues. ( -Endorphin is most abundant in the pituitary, where it exists in corticotroph cells with ACTH in the anterior lobe and in melanotroph cells with MSH in the intermediate lobe (59). Enkephalin and pre-pro-enkephalin mRNA have been identified in the adrenal medulla (60) and this has been the source of material for many studies of pro-enkephalin synthesis and regulation. Pre-pro-enkephalin mRNA has also been identified in the anterior and posterior lobes of the pituitary (61). mRNA for all three opioid precursors has been identified in the reproductive system (62—64). POMC... 

Reproductive System. The primary PGs are intimately involved in reproductive physiology (67). PGE2 and PGP2Q, are potent contractors of the pregnant utems and intravenous infusion of either of these compounds to pregnant humans produces a dose-dependent increase in frequency and force of uterine contraction. PGI2 and TXA2 have mild relaxant and stimulatory effects, respectively, on uterine tissue. The primary PGs also play a role in parturition, ovulation, luteolysis, and lactation and have been impHcated in male infertility. 

Finally, a new class of antispermatogenic agents containing the same fundamental structure cited above has been described (76JMC778). 1-Halobenzyl-l J/-indazole-3-carboxylic acids are potentially useful for birth control, and because they act after a single administration they are of interest for the physiological study of the male reproductive system. 

In order to fully appreciate the potential implications of endocrine disruption, it is important to consider the normal role of hormones in controlling the development and functioning of the reproductive systems of the different vertebrate classes. 

In addition to their endocrine disrupting properties, it must be appreciated that many of the chemicals in question possess more general toxic properties, which may be potentiated by metabolism by the organism. Several PAHs, PCBs and PCDDs are carcinogenic, while certain phthalate esters can enhance the excretion of zinc, potentially leading to zinc deficiency. Zinc, an essential element, plays a vital role in spermatogenesis and mature T-cell production. Deficiency may result in abnormalities of the male reproductive system, depletion of spermatogenesis and suppression of the immune system. 

Effects of Oestrogen on the Development and Function of the Male Reproductive System... 

---