1 The a,-adrenoceptor subtypes mediating contractions of the smooth muscle in human prostatic urethra and branches of internal iliac artery were characterized in isometric contraction experiments. 2 Phenylephrine produced concentration-dependent contractions in both the urethra and artery. These responses were competitively inhibited by prazosin, WB4101 and 5-methyl-urapidil, and the slopes of Schild plots for all these antagonists were close to unity. 3 The pA2 values for prazosin were not significantly different between the urethra (9.42 ± 0.11; mean ± s.d.) and artery (9.50 0.27), while the pA2 values for WB4101 and 5-methyl-urapidil in the human prostatic urethra (8.94 0.19 and 8.42 0.14, respectively) were significantly greater than in the branches of human internal iliac artery (7.94 0.21 and 7.43 ± 0.22, respectively; P<0.01).4 Pretreatment with chlorethylclonidine (CEC) at concentrations ranging from 0.1 IJM to 1I00 1M attenuated the maximum contraction to phenylephrine in a concentration-dependent manner in both the urethra and artery. However, the urethra was significantly less affected by CEC than the artery. The pD'2 values (negative logarithm of the molar concentration of antagonist which reduced the maximum contraction to one half) in the urethra and artery were 4.35 ± 0.27 and 5.20 ± 0.37, respectively (P<0.0 1). 5 The present results indicate that there are distinct populations of a,-adrenoceptor subtypes in the human prostatic urethra and branches of the internal iliac artery. The a1-adrenoceptors responsible for the contraction of the human internal iliac artery branches are predominantly ax1-subtype, whereas those in the human prostatic urethra are considered to be not a,3, but atc or possibly O1A or a1A/D-subtype.

Retroperitoneal laparoscopic adrenalectomy is feasible for primary aldosteronism. However, Cushing's syndrome is presently a much more difficult indication than primary aldosteronism for this new operative technique.

Between January 17, 1992 and July 31, 1993, 11 patients with primary aldosteronism, 3 with Cushing's syndrome and 3 with a nonfunctioning adrenal tumor underwent laparoscopic adrenalectomy at our university hospital. In every patient adrenal tumor was removed successfully with adjacent normal adrenal tissue. The initial 10 operations were performed without use of an ultrasonic aspirator or argon beam coagulator, and the subsequent 7 procedures were done with those items. There was no difference between the groups in intraoperative blood loss or operative time. However, the tumors in the former group were significantly smaller than those of the latter group (mean 6.70 gm. versus 13.43 gm., respectively, p < 0.05, t test). For right tumors the argon beam coagulator was useful to resect or coagulate the liver, since adrenal tumors were sometimes tightly attached to the liver and upward retraction sometimes caused liver laceration. In obese patients or those with Cushing's syndrome the ultrasonic aspirator was useful to remove retroperitoneal fat surrounding the adrenal tumor without injury to the small vessels. The mean hospital stay for these 17 patients (11.63 days) was significantly shorter than that of 16 patients with corresponding adrenal tumors undergoing open removal during the last 5 years (17.32 days, p < 0.05 t test). In conclusion, laparoscopic adrenalectomy is feasible for the surgical treatment of primary aldosteronism, Cushing's syndrome and nonfunctioning adrenal tumors. The ultrasonic aspirator and argon beam coagulator may be useful for laparoscopic adrenalectomy.

No abstract

BackgroundPheochromocytomas are rare catecholamine-producing neuroendocrine tumors. Hypertension secondary to pheochromocytoma is often paroxysmal, and patients occasionally present with sudden attacks of alternating hypertension and hypotension. Spontaneous, extensive necrosis within the tumor that is associated with catecholamine crisis is an infrequent complication of adrenal pheochromocytoma, but its pathogenesis remains unclear.Case presentationA 69-year-old Japanese man developed acute-onset episodic headaches, palpitations, and chest pains. During the episodes, both marked fluctuations in blood pressure (ranging from 40/25 to 300/160 mmHg) and high plasma levels of catecholamines were found simultaneously. Radiological findings indicated a 4-cm left adrenal pheochromocytoma. These episodic symptoms disappeared within 2 weeks with normalization of plasma catecholamine levels. Two months later, the patient underwent adrenalectomy. Microscopic examinations revealed pheocromocytoma with a large central area of coagulative necrosis. The necrotic material was immunohistochemically positive for chromogranin A. Granulation tissue was adjacent to the necrotic area, accompanied by numerous hemosiderin-laden macrophages and histiocytes with vascular proliferation. Viable tumor cells, detected along the periphery of the tumor, demonstrated pyknosis, and the Ki-67 labeling index was 2 % in the hot spot. No embolus or thrombus formation was found in the resected specimen harboring the whole tumor. The Pheochromocytoma of the Adrenal gland Scaled Score was 2 out of 20. The patient’s postoperative course was unremarkable for > 7 years.ConclusionsPresumed causal factors for the extensive necrosis of adrenal pheochromocytoma in previously reported cases include hemorrhage into the tumor, hypotension induced by a phentolamine administration, embolic infarction, high intracapsular pressure due to malignant growth of the tumor, and catecholamine-induced vasoconstriction. In the present case, histopathological and clinical findings suggest that under conditions of chronic ischemia due to catecholamine-induced vasoconstriction, an acute infarction occurred after sudden attacks of alternating hypertension and hypotension. Over the subsequent 2 weeks, repetitive massive release of catecholamines from the infarcts into circulation likely accelerated infarction progression by causing repeated attacks of alternating hypertension and hypotension and resulted in the large necrosis. This case highlights the need for physicians to consider acute spontaneous tumor infarction accompanying episodic catecholamine crisis as a rare but severe complication of pheochromocytoma.