Effects of caffeine intake during pregnancy and lactation on the skin of rats and offspring and their relationship to maternal serum concentrations of cortisol

The aim of this study was to investigate the effects of maternal caffeine intake during pregnancy and lactation on the skin of rats and their offspring, as well as their relationship to maternal serum levels of cortisol. 24 adult Wistar rats were equally divided into four groups represented by the control and treated with caffeine at doses of 25, 50 and 100mg/kg. The groups received caffeine by orogastric tube during the entire pregnancy and lactation. The control received distilled water as placebo. Different types of hair follicles and the thickness of the epidermis were assessed and quantified. Immunohystochemistry technique using antibody anti-CDC47 was used to evaluate cellular proliferation of the epidermis and hair follicles of the mothers. Also in the mothers, serum levels of cortisol were measured by the chemiluminescence technique. Data were submitted to analysis of variance comparing mediums by Kruskall Wallis Test and SNK. In groups treated with caffeine 25 and 50mg/kg, both mothers and their puppies had focal alopecia and/or hypotrichosis. Despite the higher frequency of macroscopic changes on the mothers, these lesions were diffuse when present on the puppies. Histological analysis showed calcinosis of hair follicles in the mothers and their puppies. But morphometry revealed significant difference in the number of hair follicles from mothers, as well as a significant reduction of cell proliferation of hair follicles in the group treated with 50mg/kg of caffeine. Maternal cortisol levels were significantly elevated in the group treated with 100mg/kg of caffeine. It is concluded that caffeine intake by pregnant and lactating rats can cause skin lesions in both the mothers and their offspring, characterized by alopecia and/or hypotrichosis, regardless of serum levels of maternal cortisol.