Pancreatic microcirculation in the monkey with special reference to the blood drainage system of Langerhans islets: light and scanning electron microscopic study

The microcirculation of the pancreas in 20 monkeys (Macaca mulatta) was further studied by scanning electron microscopy (SEM) of vascular corrosion casts and light microscopy (LM) of Chinese ink-injected/cleared tissues. The results revealed that 91% of islets observed received arterial blood from the terminal branches of the intralobular arteries--the afferent arterioles, and 9% received no arterial blood, being entirely supplied by the efferent vessels of the intermediate or large islets. Some islets received blood from the translobular afferent arterioles of the adjacent lobule. Two patterns of islet drainage channels with different features in the monkey were demonstrated in our study. These patterns might be termed as continuous or convergent portal vessels. All islets possessed continuous portal vessels, 7-8 microns in diameter, which ran a short distance (approximately 100 microns) and then drained into the peri-islet acinar region, forming a typical continuous insulo-acinar portal system. About 21% of the islets possessed one or two convergent portal vessels, occasionally more. This was first observed in the monkey. These vessels were relatively long and/or thick and drained into different regions: (1) the acinar region far from the islet in the lobule, forming a convergent insulo-acinar portal system, (2) crossed the interlobular septum into an adjacent lobule where sometimes no islet existed and then drained into the exocrine acinar region, forming a translobar convergent insulo-acinar portal system, (3) drained into an adjacent small islet through the insulo-insular drainage vessels--one part of the drainage system of the islets. Translobular vascular anastomoses observed between the microcirculation of pancreatic lobules in the monkey formed a new arrangement of pancreatic microcirculation-translobular pancreatic microcirculation. The functional and clinical significance of the pancreatic portal circulation and translobular circulation is discussed in this report.

Pancreatic microcirculation in the monkey with special reference to the blood drainage system of Langerhans islets: light and scanning electron microscopic study

The microcirculation of the pancreas in 20 monkeys (Macaca mulatta) was further studied by scanning electron microscopy (SEM) of vascular corrosion casts and light microscopy (LM) of Chinese ink-injected/cleared tissues. The results revealed that 91% of islets observed received arterial blood from the terminal branches of the intralobular arteries--the afferent arterioles, and 9% received no arterial blood, being entirely supplied by the efferent vessels of the intermediate or large islets. Some islets received blood from the translobular afferent arterioles of the adjacent lobule. Two patterns of islet drainage channels with different features in the monkey were demonstrated in our study. These patterns might be termed as continuous or convergent portal vessels. All islets possessed continuous portal vessels, 7-8 microns in diameter, which ran a short distance (approximately 100 microns) and then drained into the peri-islet acinar region, forming a typical continuous insulo-acinar portal system. About 21% of the islets possessed one or two convergent portal vessels, occasionally more. This was first observed in the monkey. These vessels were relatively long and/or thick and drained into different regions: (1) the acinar region far from the islet in the lobule, forming a convergent insulo-acinar portal system, (2) crossed the interlobular septum into an adjacent lobule where sometimes no islet existed and then drained into the exocrine acinar region, forming a translobar convergent insulo-acinar portal system, (3) drained into an adjacent small islet through the insulo-insular drainage vessels--one part of the drainage system of the islets. Translobular vascular anastomoses observed between the microcirculation of pancreatic lobules in the monkey formed a new arrangement of pancreatic microcirculation-translobular pancreatic microcirculation. The functional and clinical significance of the pancreatic portal circulation and translobular circulation is discussed in this report.

Morphology of pancreatic microcirculation in the monkey: light and scanning electron microscopic study

The morphology of the microcirculation of the pancreas in 20 monkeys (Macaca mulatta) was studied by scanning electron microscopy (SEM) of vascular corrosion casts and light microscopy (LM) of China ink-injected/cleared tissues. The principal results were that 1) insulo-acinar portal vessels were found between the endocrine and exocrine parts in the pancreas. The blood flows from the endocrine to the exocrine part. 2) Depending on the different microvascular arrangement, there were two patterns of microcirculation in the islet: in 66% of islets the direction of microcirculation was from cortex to core, and in 44% from core to cortex. 3) Islets could be categorized in three classes on the basis of size: the small islets (40-100 microns in diameter), the intermediate islets (101-240 microns in diameter), and the large islets (241-340 microns in diameter). 4) Insulo-insular portal routes were observed in the pancreas of the monkey. Some intermediate or large islets were connected to an adjacent small islet by one or two, occasionally more, efferent vessels. These small islets received no arterial branch and were entirely supplied by the portal vessels--the efferent vessels of intermediate or large islets. The authors suggest this new pattern to be termed the insulo-insular portal system. 5) A single centrally located intralobular artery as the exclusive vessel supplied each pancreatic lobule of the monkey, there being no anastomosis between the intralobular arteries and any of their branches. This anatomic feature might be the morphological basis of the pancreatic microcirculatory disturbance and microvascular impairment occurring during acute pancreatitis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical trial of indapamide in the management of central diabetes insipidus]

To investigate antidiuretic effect of indapamide, ten patients with central diabetes insipidus (CDI) were observed with the treatment of 2.5-7.5 mg of indapamide per day. After the third day of therapy, their mean daily urine output reduced by about 50%, and urine osmolality increased 1.36 times. No further change was seen in urine volume and urine osmolality on the sixth day of treatment. This antidiuretic effect was similar to that of 50-75 mg dihydrochlorothiazide per day. No adverse reaction was observed in blood pressure and serum potassium concentration during indapamide therapy. These data suggest that indapamide may be a new drug in the management of CDI.

[The diagnosis and management of adrenal "incidentaloma"]

We reported seven patients with adrenal "incidentaloma", diagnosed with ultrasonography and/or computed tomography and confirmed by operation and pathological examination. Three of them were pathologically diagnosed as pheochromocytoma and one each as mixed cell adenoma, bilateral adrenocortical adenoma, leiomyoma and adrenocortical carcinoma. Only one "incidentaloma" had cortisol-secreting function. The diagnosis and management of adrenal "incidentaloma" were discussed.

[Immunohistochemical localization of CEA,EMA and keratin in salivary mucoepidermal carcinoma]

Localizations of CEA,EMA and keration in 19 cases of mucoepidermal carcinomas were investigated using the indirect immunoperoxidase technique.The results showed CEA was negative in normal salivary glands and showed faint reaction in glands near carcinoma tissue.Keratin and EMA were localized in some myoepithelial cells.The positive rates in carcinoma tissue were 78.9%,89.5% and 84.2%,respectively.The positive rates and staining intensity of CEA and EMA in carcinoma tissue gradually decreased with the decline of tumor differentitation,but that of keratin showed no variation.the author consider that CEA and EMA could become good indices in clinically diagnosing mucoepithelial carcinoma and determining tumor differentiation type cell in mucoepidermal carcinoma and have a potential to multiply express the tumor elements of epithelium and/or mesenchyma.

[Study on risk factors of tissue hypoxia in patients with diabetic retinopathy]

Risk factors of tissue hypoxia was investigated in 26 patients with diabetic retinopathy (DMR), who compared with 62 patients without DMR. significant higher incidence of DMR was found in patients with poor diabetic control (HbA 1 greater than or equal to 10%), with orthostatic hypotension (OH), with peripheral neuropathy and with atherosclerosis respectively. Erythrocyte 2,3-diphosphoglycerate (2,3-DPG) was lower (P less than 0.05) and venous oxygen tension in pedal dorsum (PvO2) higher (P less than 0.05) in DMR patients than those in uncomplicated DMR patients and normal subjects. There was a rank correlation between DMR severity and PvO2 (r = 0.429, P less than 0.05), which imply that decreased blood oxygen utilization may be related to diabetic microangiopathy. These data suggested that abnormal changes of HbA 1 and 2,3-DPG, decrease of peripheral blood oxygen utilization, atherosclerosis, OH and neuropathy might be risk factors of tissue hypoxia in DMR patients.