Acute effects of caffeine administration on the ultrastructure of the golden hamster parathyroid gland.

This study was conducted to evaluate the acute effects of caffeine on the ultrastructure of the parathyroid glands in golden hamsters. Caffeine was given orally at either 2.5 mg (low dose) or 10 mg (high dose) per 100 g body weight. Caffeine caused a dose dependent decrease of the serum calcium level 2 hours after administration. Transmission electron microscopy of the parathyroid gland revealed that the volume densities occupied by the Golgi complexes and rough endoplasmic reticulum (RER) were found significantly higher 2 hours after receiving high dose of caffeine. Statistical analysis revealed no significant differences regarding to the bone mineral content (BMC) and bone mineral density (BMD). It is considered that the synthesis of parathyroid hormone is stimulated following caffeine administration.