Carbon monoxide production and reticulocyte count in normal women. Effect of contraceptive drugs and smoking.

Endogenous production of carbon monoxide (VCO), serum bilirubin (SB) and reticulocyte (retic) count have been followed during the menstrual cycle in 12 women (4 of them smokers) without contraceptive drugs and in 10 women (5 of them smokers) on contraceptive drugs. During the progesterone phase (Pph), VCO in the non-smokers was 18.2 +/- 2.1 mumol/mmol total body heme (TBH) and day (mean +/- 1 S.E.M.), compared with 10.1 +/- 1.0 during the estrogen phase (Eph). In the smokers, VCO was 10.4 +/- 1.9 during Pph and 12.5 +/- 0.7 during Eph. SB for the non-smokers was 5.2+/- 1.0 mug/ml during Pph and 3.9 +/- 0.5 during Eph, compared with 3.2 +/- 0.8 and 3.9 +/- 1.2, respectively, for smokers. The retic count for the non-smokers was 64.1 +/- 4.7 times 10(3)/mul during Pph and 17.7 +/- 5.1 during Eph. In the smokers the corresponding counts were 93.6 +/- 15.9 and 60.8 +/- 7.6. These results confirm earlier reports that VCO is increased during Pph and indicate that the rise could be due to a change in red cell catabolism, since it is concomitant with a significant increase in retic counts, which has not been found in earlier works on VCO, but which is known from reticulocyte studies. Furthermore, the results may indicate that persistent smoking affects the metabolism of CO and/or heme, since the smokers did not react with any change in VCO during Pph. In subjects using contraceptive drugs, VCO was significantly higher (14.9 +/- 0.6 on combined estrogen-gestagen drugs and 14.5 +/- 1.1 on continuous gestagens, respectively) than during Eph in non-smokers (10.1 +/- 1.0 mumol/mmol TBH and day), which might be taken as the baseline group. This indicates that the increased VCO in subjects on contraceptive drugs may be related to the activity of gestagens, which were concluded in all contraceptive drugs tested.