Histostereological Teratogenic Effects of In-utero Exposure to Alcohol on the Fetal Liver in Albino Rats (Rattus norvegicus)

Abstract

In-utero exposure to alcohol has been shown to perturb the normal development of the fetal liver. Though data exist on the alcohol teratogenicity to the fetal viscera, there is paucity of data on the anatomical histo-stereological effects of alcohol when administered in varying doses and at different gestational periods. The broad objective of this study was therefore to evaluate the histo-stereological effects of prenatal exposure to varying doses of alcohol on the fetal liver when exposed at different gestational periods in albino rats. In carrying out the study, animal experimentation was done in SAFARI animal house while tissue processing was done in the Department of Human Anatomy, JKUAT. A static-group experimental study design was adopted where 30 albino rats (dams) weighing between 200 to 230gm from a pure colony were used as the experimental model. These 30 dams were broadly organized into two study groups namely control (n=3) and experimental (n=27) group. The 27 rats in the experimental group were further assigned into three study groups of nine (9) rats each according to study dosages as (i) low alcohol group (2g/kgbwt), (ii) medium alcohol group (3.5g/kgbwt) and (iii) high alcohol group (5g/kgbwt). These 9 rats in each of the three study groups were further subdivided into three study groups with 3 rats each according to trimesters as (i) 3 rats in TM1, (ii) 3 rats in TM2 and (iii) 3 rats in TM3. All rats in trimester 1(TM1) study groups received alcohol treatment from gestational day (GD) one all through to gestational day 20 (GD 1-20), those in TM2 study category received alcohol treatment from GD 7-20 while those in TM3 received alcohol treatment from GD 14-20. In addition, all the rats received standard rodent pallets and water ad libitum throughout the gestational period and were humanly sacrificed on the 20th day of gestation. A total of 90 fetuses (three fetuses having the lowest, median and highest fetal weight from each animal) had their livers harvested, fixed in 10% formaldehyde and processed for histological and stereological analysis. Data was collected using structured datasheets and photomicrographs. The data was then analyzed using STEPnizer software and SPSS version 23 where One-way Analysis of Variance (ANOVA), followed by Tukey’s post hoc multiple comparison tests were done. The results were expressed as mean ± standard error of the mean (SEM) for all values. The findings were then presented in form of bar graphs and tables. A significant reduction (P<0.05) in the fetal weights, CRL and head circumference were observed. Varying histo-morphological changes of the liver including constriction of the central vein, dilatation of the liver sinusoids and reduction in hematopoietic tissues among others were observed too. A significant increase (P=0.001) in total liver volume and volume densities were also observed. In conclusion, the present study revealed that alcohol consumption during pregnancy is teratogenic and has a wide array of fetal teratogenic outcomes. In addition, alcohol caused hepatomegaly in time and dose dependent manner. It is therefore recommended that expectant mothers should abstinence from alcohol consumption.