Silicone rubber nipples: effects of sesame-oil extract on reproduction in mice.

The authors investigated a type of silicone rubber (SR) nipple for toxicity, caused by chemical migrants, on reproduction and pregnancy outcomes. They followed an extraction method (set forth in the 20th revised edition of the United States Pharmacopeia) in which sesame oil was a vehicle. They prepared the extract daily and administered it orally (50 ml/kg of body weight) into pregnant Swiss albino mice from gestation Day 0 until delivery. They gave a control group of mice the pure vehicle that was subjected to the same conditions. The authors recorded pregnancy weight gain, gestation period, litter size, stillbirths, and offspring sex ratio. They performed an enzyme-linked immunosorbent assay for pregnancy hormones (progesterone, estradiol, and prolactin) for each trimester and monitored birth weight, growth rate, and sex hormone levels (follicle-stimulating hormone, luteinizing hormone, and estradiol in females; testosterone in males) in offspring. The authors detected SR-extractable chemicals by means of gas chromatography and mass spectrometry. The decrease in weight gain from Day 6 of gestation until delivery and the shortness in the gestation period were significant in dams (p< or = .05). Newly born pups demonstrated a significantly (p < or = .05) lower body weight that continued with age, and this became highly significant (p< or = .01) from Day 6. Blood hormone levels in dams and offspring indicated no significance. In conclusion, the studied SR nipples indicated leachability, which could affect reproduction, without a manifest endocrine modulation.

Effects of snake venom from Saudi cobras and vipers on hormonal levels in peripheral blood.

OBJECTIVE: Knowledge about the effects of snake venoms on endocrine glands in the Kingdom of Saudi Arabia (KSA) is meager. The aim of the present study is to investigate the acute and chronic envenomation from 4 snakes out of 8 species of Saudi Cobras and Vipers on the tissues of endocrine glands and peripheral hormonal levels in male rats. METHODS: The peripheral blood levels of 4 hormones mainly testosterone, cortisol, insulin and thyroxin were investigated in male Wistar rats following acute and chronic treatment of the rats with poisonous snake venoms at the Department of Physiology, Faculty of Medicine, King Abdul-Aziz University, Jeddah, Kingdom of Saudi Arabia between September 2000 to May 2001. RESULTS: Using radio immunoassay for hormonal analysis, a rise in testosterone levels in peripheral blood was obtained following acute treatment, which is due to the effect of the venoms on vascular permeability and increased blood flow. In contrast, the chronic treatment with venoms resulted in a delayed effect on vascular permeability and testicular degeneration resulting in a decreased blood flow and a significant drop in testosterone concentration. Cortisol levels were no different from the controls during acute treatment but it demonstrates gradual rise following chronic treatment to withstand the stress imposed on the animals. Similar results were obtained for insulin, which showed normal values with acute treatment but decreased levels of chronic treatment suggesting insulin insufficiently. Likewise, the thyroxin levels were decreased with chronic treatment suggesting a toxic effect of the poison on the rich blood supply of the thyroid follicles with a subsequent decrease in blood flow to the tissues and therefore, decreased thyroid hormone levels. CONCLUSION: The effects of venom toxicity on testosterone levels were either normal or stimulatory with acute treatment or inhibitory with chronic treatment depending on the vascular blood flow and testicular degeneration. Cortisol levels were normal at acute treatment but showed a gradual rise reflecting the stress imposed on the animals. The rise in cortisol levels was visualized to potentiate the cardiovascular and metabolic changes. The effects on insulin and thyroxin were similar to those of testosterone level showing normal or stimulatory effect with acute treatment followed by decreased levels of hormones with chronic treatment.