It is a new approach to investigate the ultrastructure, function and metabolism of each segment of uriniferous tubule using dual environment culture chambers (DECC). In the present study the DECC culture of proximal tubule cells was undertaken with millcell-HA culture insert in the mixed medium of Ham's F12 and Dulbecco's modified Eagle's medium.A monolayer of proximal tubule cells was obtained in the medium mixed by constant bubling of oxygen at 3 weeks after seeding. Transmission electron microscopy revealed the cuboidal cells with microvilli, abundant mitochondria, vacuoles, lysosomes, and irregular plasma membrane infoldings. Also, the monolayer exhibited active metabolism from the release of ~(14)C-I-carbon dioxide and absorption ability of ~(14)C-I-glucose across the cultured monolayer. In addition, the culture procedure has been introduced in detail.

In the present experiments, the effect of hypertonic NaCl infusion on the renal ultrastructure in rabbits with hypovolemia was examined by electron microscopy. Rabbits were anasthetized with pentobarbital sodium and submitted to control bleeding and held at a mean arterial pressure of 40 mm Hg for 45 minutes. They were then given 6 ml/kg i. v. of 1) isotonic NaCl (300 mosm/L; 2) hypertonic NaCl (2400mosm/L). Only animals receiving hypertonic NaCl had immediate and permanent resto ration of mean arterial pressure and nearly intact ultrastructure of nephron. However, the animals with isotonic NaCl had an ischemic changes of nephron ultrastructure and unrestored mean arterial pressure.

Objective　To analyse the development of mouse kidney. Method　Sterological methods were used in this study.Results　The nephrogenic zone appeared in 14th day's kidney of the fetus development, medulla could be found in the late stage of fetus development kidney and developed after birth. Inner medulla were observed on 21st day after birth, nephrogenic zone disappeared on 7th day after birth. Morphometric analysis proves that medulla developed mainly after birth, cortex volume also developed rapidly after birth, especially after 21st day postnatally, the development of corpuscle number was finished before 7th day postnatally. Conclusion　The development of mouse kidney begins on 14th day of embryo and stops on 21st day after birth, the period of the medulla development is between E 18 days and 21 days after birth.

An ultrastructural analysis of distal nephron has been investigated using morphometric method for rats with hyperthyroidism and hypothyroidism. The cells analysed were distal convoluted tubule cells (DCT cells), distal straight tubule cells (DST cells), intercalated cells (I cells) and principal cells (P cells) of collecting duct. The cells were sampled from superficial cortex. The results revealed that in DCT, DST and P cells the profile area of cells, the surface density of plasma membrane (Sv), the boundary length of cell surface [B(A)], the volume density (Vv) of mitochondria, and the length of microvilli were significantly decreased in the rat with hypothyroidism. However, in the rat with hyperthyroidism there were an obvious increase of profile area of cell and Vv of mitochondria in I cells. The results suggest that thyroid hormone is an important factor for maintaining the normal cellular structure in the distal nephron. The morphometry shows that the changes of DCT, DST and P cells are distinct in the rat with hypothyroidism, and the ultrastructural changes of I cell are obvious in the rat with hyperthyroidism.

Objective To observe apoptosis of renal development in mouse. Methods Light,electron microscopy and TUNEL method were used. Results The apoptosis could be easily found in cells between S like body in nephrogenic zone and in renal corpuscles before birth, especially at 14 18 days prenatally. The apoptotic cells in epithelia of renal tubule or collecting duct could be observed in postnatal renal medulla. In medullary papilla the cell death peaked around postnatal day 7. Electron microscopy revealed that apoptotic cells were ingested by neighboring cells. Some apoptotic cells detached from epithelia into the lumen of tubule or duct. Conclusion This study provides morphologically some evidences of apoptosis in the mouse kidney embryonically and postnatally. The apoptosis in cortex was apparently related to the development of nephrogenic zone and renal corpuscles; and the apoptosis in medulla might play an important role in the development of renal tubular epithelia. [