Rat uterus renin-like activity: effect of stimuli and hormones.
1 The characteristics of renin-like activity in rat uterus were studied. The optimum temperature was 50 degrees C and optimum pH 4.0. Potassium (100 mM) enhanced this activity but sodium or calcium had no effect. 2 Uterine renin-like activity was unchanged 24 h after bilateral nephrectomy. 3 Renin-like activity in the uterus increased slowly from birth to 4 weeks of age and faster between the 4th and 8th week. 4 Ovariectomy caused a considerable fall in uterine renin-like activity. 5 The following factors, known to affect renin secretion in the kidney, i.e., hypovolaemia, sodium loading, adrenalectomy, administration of desoxycorticosterone acetate and injection of isoprenaline, had no effect on uterine renin-like activity. 6 Stilboestrol, an oestrogen, caused a significant increase of uterine renin-like activity. Progesterone and testosterone had no significant effect on this activity but blocked the increase caused by stilboestrol. 7 During pregnancy there was a small but significant fall of renin-like activity in the uterus in the first week and a continuous increase throughout the later period of pregnancy. 8 It is concluded that uterine renin-like activity is independent of kidney renin and does not respond to stimuli  affecting kidney renin. Uterine renin activity is hormone-dependent and may be governed by the ratio, oestrogen : progesterone.
D000311:Adrenal Glands / Q000502:physiology; D000367:Age Factors; D000818:Animals; D003900:Desoxycorticosterone / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D004054:Diethylstilbestrol / Q000494:pharmacology; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology; D007668:Kidney / Q000502:physiology; D010053:Ovary / Q000502:physiology; D011247:Pregnancy; D011374:Progesterone / Q000494:pharmacology; D051381:Rats; D012083:Renin / Q000502:physiology*; D012965:Sodium Chloride / Q000494:pharmacology; D013739:Testosterone / Q000494:pharmacology; D014599:Uterus / Q000502:physiology*
D013739:Testosterone; D003900:Desoxycorticosterone; D012965:Sodium Chloride; D011374:Progesterone; D004054:Diethylstilbestrol; D003907:Dexamethasone; D012083:Renin; D007545:Isoproterenol