Late reproductive analysis in rat male offspring exposed to nicotine during pregnancy and lactation.

We previously observed that nicotine, administered to rats (Wistar) during pregnancy and lactation periods, provokes, in the progeny, late morphofunctional alterations in Leydig cell, body weight increase in adulthood (90 days post partum, dpp) as well as seminiferous epithelium injury. Aiming to investigate whether the spermatogenic damage previously observed in adult progenies from pregnant and lactating nicotine-exposed rat dams are maintained or whether it is worsened in older rats, we analyzed the morphological testicular alterations after up to two complete periods of spermatogenesis (53 days each), spermatic parameters, and sperm DNA fragmentation. Pregnant and lactating rats were nicotine-exposed (2 mg/kg/day) through an osmotic minipump implanted on the first day of pregnancy and replaced after birth. Absolute Control (no minipump) and Sham Control (minipump without nicotine) groups were established. The offspring were killed at 90, 143, and 196 dpp. Significant alterations in morphometric and stereological testicular parameters, such as concentration of sperm number, daily sperm production, and plasma and intratesticular levels of cholesterol and testosterone were not observed in nicotine-exposed rats. Testicular histopathological analysis showed small intraepithelial vacuolization and an accentuated germ cell desquamation in exposed rats. However, the offspring from nicotine-exposed dams exhibited higher frequency of morphologically abnormal spermatozoa and lower sperm motility in comparison with control groups. In addition, nicotine-exposed groups showed a significant reduction in sperm mitochondrial activity and an increased sperm DNA fragmentation (Comet assay). These results indicate a late reproductive damage in the male progeny caused by maternal nicotine exposure, related to the decrease in sperm quality.

Effects of prenatal and lactation nicotine exposure on rat testicular interstitial tissue.

Nicotine is largely consumed as a component of cigarettes. It induces apoptosis, interferes with endocrine function by changing the sex hormones secretion and leads to male infertility. Testosterone is produced from cholesterol by Leydig cells (LC), with the participation of testicular macrophages (MO). Thus, to investigate whether nicotine administration to pregnant and lactating rats changes cholesterol and sexual hormone levels and LC and MO populations of offspring, female rats received nicotine (2 mg/kg/day) through osmotic minipumps from the first day of pregnancy up to the end of weaning. At 1, 30, 60 and 90 days post-partum (dpp) the plasma cholesterol and testosterone levels were obtained, as well as the biometric, histopathological and stereological testicular parameters. Nicotine reduced the body weight, cholesterol levels and lipid droplet number in foetal LC at 1 dpp. The number of apoptotic LC did not change in the offspring of nicotine group at any age studied. No alterations in the numerical densities of MO and LC occurred at 60 and 90 dpp. Hypertrophy of mature LC and increase in cholesterol and testosterone levels were noted at 90 dpp. In conclusion, nicotine when administered to rats throughout pregnancy and lactation induces morphofunctional alterations of foetal and mature LC and affects cholesterol and testosterone levels.