Carbon Monoxide Production and Reticulocyte Count in Normal Women

The endogenous production of carbon monoxide (CM) serum bilirubin (SB) and reticulocyte (retic) count was studied in 12 women who were not taking oral contraceptives (OC) 4 of whom were smokers and 10 women who were taking OCs 5 of whom were smokers. Among non-smokers not using OCs CM levels were significantly (p less than .001) higher during the progesterone phase (Pph) of the menstrual cycle than the estrogen phase (Eph). SB levels were not significantly different during Pph and Eph (p more than .05). Total body hemoglobin (TBH) did not change between phases. The rectic count was significantly higher during Pph than Eph (p less than .001). Among smokers not using OCs CM did not significantly differ between the phases (p more than .05) but was significantly lower than those values for non-smokers during Pph (p less than .01) and probably significantly higher during (p less than .05). There were no differences in TBH between the phases and in comparison with non-smokers. The rectic count in smokers was significantly higher during Pph compared to Eph (p less than .01) and was also higher in both phases than values for non-smokers. CM and rectic counts for both smokers and non-smokers were significantly higher during Pph than Eph (p pess than .05 p less than .01 respectively). Among 4 women using a combined OC 1 of whom smoked there were no significant differences between CM levels during treatment and drug-free days. In 6 women using gestagens 4 of whom were smokers and 2 of whom were using parenteral preparations the non-smokers showed larger variations in CM from week to week than smokers. The increase in CM may be due to a change in red cell catabolism. Since CM was higher during Pph among subjects using OCs than among non-smokers during Eph it is suggested that the increase in CM may be related to the activity of gestagens.