Delayed onset of pulmonary hypertension associated with an appetite suppressant, mazindol: a case report.

The use of the appetite suppressant agents aminorex and fenfluramine derivatives has been reported as a risk factor for the development of pulmonary hypertension. A 29-year-old female developed pulmonary hypertension suspected to be due to an amphetamine-like appetite suppressant agent, mazindol ((+/-)-5-(p-chlorophenyl)-2,5-dihydro-3H-imidazo [2,1-a] isoindol-5-ol). She was admitted to Sapporo Medical University Hospital with dyspnea due to severe pulmonary hypertension. Twelve months prior to admission, she had taken mazindol continuously for a period of 10 weeks. As yet, her pulmonary hypertension has not completely improved. This is the first reported case of mazindol-associated pulmonary hypertension, which developed after a long latent interval, and it suggests that mazindol is also a risk factor for the development of pulmonary hypertension, making long-term follow-up necessary for patients taking this anorectic agent.

Differences in autonomity of growth hormone secretion in patients with acromegaly.

Thirteen patients with acromegaly were subjected to the examination of autonomity in growth hormone (GH) secretion. TRH (500 mug iv), arginine (0.5 g/kg of body weight iv infusion), LH-RH (100 mug iv) and L-dopa (500 mg orally) were administered, and plasma GH was measured. Among them, 11 patients showed some response in plasma GH to at least one agent, but the other 2 cases showed no response to any of the above 4 agents. In the former 11 cases, the patients were regarded as belonging to the less autonomous type and in the latter 2, to the more autonomous type in GH secretion. Six cases (4 cases of the less autonomous and 2 cases of the more autonomous type) received an administration of 500 mug of synthetic somatostatin parenterally. Following administration of somatostatin, the patients of both types showed significant GH decrease, although GH decrease in the more autonomous type was smaller than that of the less autonomous type. These results would suggest that there might be no acromegalics secreting GH FROM THE PITUITARY WITH COMPLETE AUTONOMITY, AND THE DIFFERENCE OF AUTONOMITY IN ACROMEGALIC PATIENTS MIGHT DEPEND EITHER ON THE DIFFERENCE IN SENSITIVITY AND/OR THE NUMBER OF RECEPTORS IN THE PITUITARY RATHER THAN THOSE IN HYPOTHALAMUS TO EXOGENOUS STIMULI.

Responsiveness of growth hormone release in acromegalics after irradiation or hypophysectomy.

Effects of X-ray irradiation to the pituitary and transfrontal hypophysectomy were evaluated on the responsiveness of plasma growth hormone (GH) to exogenous stimuli in 8 patients with acromegaly. As exogenous stimuli, arginine, TRH, LH-RH and L-dopa were administered. In 2 out of 3 patients treated with Liniac irradiation, the responsiveness to arginine was essentially unchanged, while in the third patient positive response to arginine disappeared after therapy. Of 2 patients who received a combination of hypophysectomy and Liniac irradiation, the responsiveness to arginine, TRH, LH-RH and L-dopa did not change in 1 patient, but in the other it was observed that negative response to L-dopa became positive after the treatment, remaining the unchanged responsiveness to arginine, TRH, and LH-RH. In 3 hypophysectomized patients, little change in responses to the above 4 stimuli was observed. In summary, out of 22 pairs of responses (pre- and post-therapy) examined 20 were not altered. In 11 pairs of responses (pre- and post-irradiation) particularly, 10 were essentially unchanged. It might be concluded that the responsiveness of GH to exogenous stimuli in acromegalics would not be affected by irradiation or transfrontal hypophysectomy.