Vasopressin and oxytocin responses to acute and chronic osmotic stimuli in man.

The regulation of both arginine vasopressin (AVP) and oxytocin secretion was studied during rapid and prolonged osmotic stimuli in normal adult volunteers. In five subjects given an intravenous infusion of 0.85 mol NaCl at 0.05 ml/kg per min over 2 h there was a significant (P less than 0.05) rise only in plasma AVP, with no significant change in plasma levels of oxytocin. In six further subjects 5 days of restriction to 500 ml fluid daily resulted in significant increases of both plasma and 24-h urinary AVP, whereas there was no change in corresponding oxytocin levels. During another 5-day period in which the same subjects were given an additional 200 mmol sodium as well as having their fluid intake restricted to 1000 ml daily, there were again significant rises in plasma and 24 h urinary AVP with no change in corresponding oxytocin levels. We conclude that, in man, AVP is selectively secreted in response to both dehydration and high sodium intake, whilst even after the stimulus of rapidly increasing plasma osmolality during intravenous infusion of hypertonic saline the rise in oxytocin is not statistically significant. It therefore appears unlikely that oxytocin has a significant role in the physiological control of fluid balance in man.

The effect of LHRH agonist therapy in the treatment of endometriosis (English experience).

The preliminary findings of a comparative study of buserelin and danazol in the treatment of endometriosis are presented. Eighty patients with laparoscopically proven symptomatic endometriosis have been allocated at random to open treatment with intra-nasal buserelin or oral danazol. Forty-five patients have been assessed after completion of seven months treatment. Changes in endometriotic lesions have been examined by second laparoscopy and scored according to a modification of the criteria of the American Fertility Society (AFS). Both treatments were associated with reductions in modified AFS scores reflecting partial resolution of the condition. Adverse effects were reported with the use of both drugs, but appeared to be more extensive during therapy with danazol. Further evaluation and post treatment follow up are required.