Effects of Maternal Alcohol Consumption on the Allometric Growth of Muscles in Fetal and Neonatal Rats

Abstract

The effect of maternal alcohol consumption during pregnancy as well as the neonatal period on allometric growth of skeletal muscles of fore and himdlimbs was studied in 252 rats (126 males and 126 females). At the inception of the study the dams of alcohol-exposed groups received 10% ethanol (v/v) in water for 2 weeks and 20% ethanol (v/v) for another 3 weeks. They were then bred overnight by introducing 1 male per 4 females into the cage. Following diagnosis of pregnancy, the two alcohol-exposed groups received 30% ethanol (v/v) till delivery. Neonatally the pre- and postnatal alcohol-exposed group continued to receive alcohol till weaning at 21 days of age. The offspring randomly selected (7 males and 7 females) from each group were killed at 3, 5, 7, 9, 11 and 14 weeks of age. The body weights, muscle weights and percentage of body weights contributed by each muscle were significantly smaller in the offspring of the alcohol-exposed groups as compared to the controls. These parameters were significantly higher in the group exposed to alcohol only prenatally as compared to those exposed both pre- and postnatally up to the 7th week of age, and thereafter were similar in the subsequent weeks. Although the alcohol-exposed groups grew faster than the controls from 9 to 14 weeks of age, they were, however, not able to catch up. This demonstrated that allometric growth of muscles of fetal and neonatal rats was adversely affected by maternal consumption of alcohol during pregnancy and neonatally.

Prenatal alcohol exposure and early postnatal changes in the developing nerve-muscle system

“…Thus, the results of the present study clearly indicate that prenatal alcohol exposure suppresses both the hyperplasia of muscle fibers prenatally and hypertrophy of individual fibers postnatally (Ihemelandu, 1984). The degree of retardation of growth varies among different muscles (Nwaogu and Ihemelandu, 1999). Compared with the EDL muscle, the TA is less reduced in weight.…”

“…This may reflect the fact that the third postnatal week in the rat is a critical period of time when a lot of changes take place in the course of development, particularly in relation to the neuromuscular system (Vrbová et al, 1995). This observation also reaffirms that prenatal alcohol exposure produced retardation of growth and a lack of catch-up growth postnatally in the skeletal muscles (Nwaogu and Ihemelandu, 1999). It has been demonstrated that children with FAS have appropriate levels of growth hormone and cortisol (Root et al, 1975;Tze et al, 1976); therefore, it is believed that the growth deficiency in FAS reflects a prenatal insult to cell proliferation that leads to diminished fetal cell numbers and eventually to limitations in size.…”

Using zebrafish in systems toxicology for developmental toxicity testing

“…The malformation of skeletal muscle caused by exposure to alcohol during the embryonic period are also observed in zebrafish (Sylvain et al. ), chick (Chaudhuri ) and rat (Nwaogu and Ihemelandu ). It has also been demonstrated that alcohol exposure during the embryonic period disrupts the expression of sonic hedgehog, an important regulator for the somite formation (reviewed in Christ et al.…”

Foetal Alcohol Syndrome: Growth Rate of Bones in Rats

“…The reason why the humerus should behave differently from femur is not obvious. Nwaogu and Ihemelandu (1999a) reported the same relationship between growth coefficients of biceps brachii (forelimb muscle) a n d quadriceps femoris (hindlimb muscle) in prenatal alcohol exposed rats when compared with the controls. This may probably be a result of different functions performed by forelimb and hindlimbs in support of body weight of animal in a standing position (Ihemelandu and Ibebunjo, 1992).…”