Various Levels of Maternal Caffeine Ingestion during Gestation Affects Biochemical Parameters of Fetal Rat Brain Differently

Abstract

Pregnant dams were divided into four groups on day 10 of gestation. Dams of group 1 were fed an 20% protein diet as controls. Dams of groups 2, 3 and 4 were fed a 20% protein diet supplemented with 0.5 mg, 1 mg and 2 mg caffeine/100 g body weight of dams, respectively. Pups were delivered surgically on day 22, and their brains were rapidly removed and analyzed for DNA, protein, cholesterol, zinc and alkaline phosphatase activity. The dams’ brains were analyzed for the same parameters as those of the pups. Plasma and brain caffeine levels were also determined in caffeine-supplemented groups. The pups’ brains in group 2 were heavier than those in group 4. The DNA concentration of group 2 was higher than that of the other groups. The protein concentration of group 4 was higher than that of the other groups. The cholesterol concentration of group 3 and 4 was less than that of the controls. The zinc concentration of group 4 was less than that of group 2. Alkaline phosphatase activity was decreased in groups 3 and 4 compared with either controls or group 2. Dams showed no significant difference among the groups in the same biochemical parameters except for cholesterol concentration that was higher in groups 2, 3 and 4 than in the controls. Plasma and brain caffeine levels of the fetuses and plasma caffeine of the dams in group 4 were higher than those of either group 2 or 3. It is concluded that various amounts of maternal caffeine intake exert different effects on fetal brain growth. In contrast, the effect of caffeine on the dams’ brain is relatively minor.

Can Prenatal Caffeine Exposure Affect Behavioral Inhibition?

“…By what mechanism might early caffeine exposure increase the probability of inhibited behavior? Caffeine exposure has various effects on the developing fetus, such as increased arousal (Devoe, Murray, Youssif, & Arnaud, 1993), decreased brain weight (Palm et al, 1978;Groisser, Rosso, & Winick, 1982;Tanaka & Nakazawa, 1990;Tanaka, Nakazawa, Arima, & Iwaski, 1984;Yazdani, Hartman, Miller, Temples, & Nakamoto, 1988;Yazdani, Joseph, Grant, Hartman, & Nakamoto, 1990), increased deposition of zinc in various brain regions (Nakamoto et al, 1991), increased cerebral tyrosine (Tanaka & Nakazawa, 1990), and .inhibition of myelin synthesis (Fuller & Wiggins, 1981;Yazdani et al, 1988), but it is difficult to predict how these mechanisms would affect behavior. A more direct link to BI is the finding that caffeine consumption increases the concentration of norepinephrine in maternal serum (Kirkinen, Jouppila, Koivula, Vuori, & Pukka, 1983).…”