Effect of oral contraceptive containing a new progestin (ORG 2969) on plasma renin activity, growth hormone and immunoreactive insulin.

Plasma renin activity (PRA), Growth hormone (GH) and immunoreactive insulin (IRI) were studied in seven healthy subjects during the ovulatory menstrual cycle and during the first and third cycles of oral contraception with 0.05 mg of ethinylestradiol and 0.100 mg or 0.125 mg of a new progestogen, 17 alpha-ethinyl-18-methylene-4-estren-17 beta-ol. The PRA level in the second half of the control cycle was significantly higher than in the beginning of the cycle. At the end of the treated cycles it was significantly higher than at the end of the control cycle. Neither GH nor IRI showed significant changes during the control cycle. GH was significantly higher at the end of the first and third treated cycles than at the end of the control cycle. IRI was significantly higher both in the beginning and at the end of the first treated cycle than the corresponding IRI levels in the control cycle. IRI at the end of the third treatment cycle was not significantly different from corresponding means at the end of the control cycle or the first treated cycle.