Folic Acid Deficiency and Hepatic DNA Synthesis

Reversal of ethanol and indomethacin-induced suppression of hepatic DNA synthesis by 16,16-dimethyl prostaglandin E2

Investigations were undertaken to determine effectiveness of 16,16-dimethyl prostaglandin E2 (dmPGE2) in overcoming the suppressive effects of ethanol and/or indomethacin on hepatic DNA synthesis. Adult litter mate Sprague-Dawley rats were subjected to sham operation or partial hepatectomy. Immediately after partial hepatectomy, and at 8-hr intervals for 24 hr, the rats were given: (a) ethanol with and without dmPGE2 or (b) indomethacin with and without ethanol and/or dmPGE2. DmPGE2 produced a significant increase in DNA synthesis in sham-operated (p less than 0.001) and untreated partially hepatectomized animals (p less than 0.025). Ethanol and indomethacin caused a 6- and 18-fold reduction, respectively, in hepatic DNA synthesis following partial hepatectomy. DmPGE2 overcame the inhibitory effect of ethanol (p less than 0.005) and indomethacin (p less than 0.0005) in partially hepatectomized animals. Mitoses were decreased concomitantly with ethanol and/or indomethacin-induced reduction in DNA synthesis and increased with administration of dmPGE2. It is concluded that dmPGE2 increases hepatic DNA synthesis and regeneration in normal rat liver and overcomes their inhibition when ethanol and/or indomethacin is given after partial hepatectomy. Timing of dmPGE2 administration is crucial. When given 30 min before ethanol, it completely inhibits suppression of regenerative activity; omission of this "priming" dmPGE2 dose results in only 44% of DNA synthesis obtained in control animals.

Host resistance in liver disease--its evaluation and therapeutic modification

We have attempted to review some of the factors involved in host resistance and the variations in the individual responses to the infectious and noxious agents to which we are increasingly exposed. Few treatment modalities are available to favorably influence host resistance, but clearly, this approach to the treatment of liver disease represents an opportunity for the future.

Experimental nutritional folate deficiency in the baboon (Papio cynocephalus)

1. Folate deficiency was produced in baboons by feeding them on a diet which was deficient in folic acid.

2. Loss of body-weight, anorexia, asthenia, gingivitis and diarrhoea were common features of the deficiency.

3. Haematologically, the deficiency was characterized by leucopenia with a greater proportional decrease in the polymorphonuclear neutrophils, thrombocytopenia and in some baboons macrocytic anaemia.

4. Deficient baboons had low serum, erythrocyte and liver folate levels and excreted increased amounts of formiminoglutamic acid. The fall in the serum folate level was more rapid than that of the erythrocytes, occurring mainly during the 1st month of deficiency, while erythrocyte levels decreased gradually over a 5-month period.

5. Serum and liver vitamin B12levels and methylmalonic acid excretion were normal in deficient baboons.