Promoting effects of Chinese pangolin and wild pink medicines on the mammary gland development in immature mice.

The effects of the mixture of crude aqueous extracts from Chinese pangolin and wild pink (C+P), traditional Chinese medicine, on the proliferation and differentiation of mammary gland epithelium in intact and ovariectomized immature mice were investigated by light and electron microscopy and BrdU immunohistochemistry. Although there were no significant differences in mammary gland fat pad and parenchyma areas between the intact experimental groups, the numbers of duct branchings and buds were significantly larger in the C+W treated mice than in the control mice. The ratio of BrdU immunopositive cells to total epithelial cells was higher in C+W treated intact mice. Ultrastructurally, epithelial cells of the mammary buds and ducts possessed an oval and lucent nucleus, and ribosomes increased in number or developed to a greater degree in C+W treated intact mice than in the control mice. Conversely, there were no significant differences in any measurements of mammary gland between the experimental groups of ovariectomized mice. BrdU immunoreactive cells were never seen and the ultrastructure of mammary epihelial cells indicated the inactive cell phase in both ovariectomied mice. In comparison between the intact and overiectomized mice, the mammary fat pad area was larger in the ovariectomized mice than in the intact mice, although another four measurements were larger in the intact groups. These observations suggest that administration with C+W could promote the development of mammary glands via ovary in immature mice.

Strain differences in morphometrical characteristics of rat kidneys.

To clarify the strain differences in the morphology of the rat kidneys, we investigated the morphometrical characteristics of the kidneys of Slc:Wistar, Slc:SD, and F344/NSlc rats. The diameter of the renal corpuscles in female F344/N rats is smaller than that in female Wistar rats. Although sex differences (males>females) were shown in SD and F344/N rats, no effects of castration were detected in any of the groups. Strain-dependent differences in the percentage of renal corpuscles with a cuboidal parietal layer were found in both male and female groups. The highest percentage of them was noted in male Wistar rats. Effects of castration were observed in female Wistar and male F344/N rats, and the values after castration were significantly higher than those in the intact animals. As for the number of proximal convoluted tubular nuclei, no strain differences were detected in either the male or female groups. Although a sex difference was found in SD rats (female>male), no effects of castration were detected in any of the groups. In female F344/N rats, numerous numbers of PAS-positive granules, which were observed in the proximal convoluted and straight tubular epithelia, were noted. Orchiectomy induced an increase of these granules in male SD and F344/N rats, but ovariectomy showed no effects on them in any strains. This is the first study to clarify the strain differences in the morphological characteristics of the kidneys in ordinary rat strains.

Age-related morphological changes in kidneys of SPF C57BL/6Cr mice maintained under controlled conditions.

Age-related morphological changes were examined in the kidneys of inbred C57BL/6Cr mice maintained in a controlled environment. The specific pathogen free status of animals used in the present study was confirmed by microbiological monitoring. Kidneys were histologically and histometrically investigated at 3, 5, 12, 15, 24 and 27-months-old. Kidney weights did not change with age. Renal corpuscles increased in number at 24- and 27-months-old, but diameter remained constant. The percentage of renal corpuscles with a cuboidal glomerular capsule decreased at 24- and 27-months-old. Score indicating glomerular damage increased from 5- to 27-months-old. Changes to the proximal convoluted tubules were severe. Vacuolar degeneration was observed from 12-months-old. Tubular atrophy was observed at 24- and 27-months-old, with number of nuclei per unit area increasing at the same ages. Amyloidosis and scar lesions were observed at 27-months-old. Focal cell infiltration around vessels was found at 24- and 27-months-old. Electron microscopy at 27-months-old revealed expansion of the mesangial matrices and fusion of foot processes in the glomeruli. Enlarged lysosomes with lipid content were observed in the proximal convoluted tubules.

Giant lysosomes in the renal proximal tubules--a morphological characteristic of DBA/2 and DBA/1 mouse kidneys.

The DBA/2Cr mouse is characterized by the presence of giant lysosomes located in the proximal convoluted tubules of males and proximal straight tubules of females. However, it remains unclear whether these giant lysosomes in the proximal tubules are characteristic of DBA/2Cr specifically, or are common to other DBA/2 substrains and DBA/1. The present study investigated the morphology of kidneys from DBA/2CrSlc, DBA/2JJcl, DBA/2NCrj and DBA/1JNCrj mice of both sexes. Giant lysosomes in the renal proximal tubules were found to represent common morphological characteristic of both DBA/2 and DBA/1JN.

Effects of sex hormones on the development of giant lysosomes in the proximal tubules of DBA/2Cr mouse kidney.

The DBA/2Cr mouse strain is characterized by giant lysosomes that are located in the proximal convoluted tubules of males and in the proximal straight tubules of females. In the present study, we used light microscopy and electron microscopy to investigate the effects of sex hormones on the development of these giant lysosomes. In the proximal convoluted tubules of males, giant lysosomes (large vacuolar structures observed under light microscopy) disappeared after orchiectomy but reappeared after testosterone treatment. No changes were observed after ovariectomy or estradiol treatment. In the proximal straight tubules of females, giant lysosomes (periodic acid Schiff-positive giant granules observed under light microscopy) disappeared after ovariectomy but reappeared after estradiol treatment. After orchiectomy and testosterone treatment, the giant lysosomes did not appear. However, a number of small lysosomes (smaller than a nucleus), which were periodic acid Schiff-positive, increased after orchiectomy and decreased after testosterone treatment. These findings suggest that lysosomes in DBA/2Cr mice are regulated by testosterone or estradiol as follows: (1) in the proximal convoluted tubules, the development of lysosomes is stimulated by testosterone but not by estradiol; (2) in the proximal straight tubules, development of lysosomes is stimulated by estradiol and inhibited by testosterone.

A simple method for the specific detection of Ren-1 renin.

BACKGROUND: Ren-1 and Ren-2 renin are expressed in the kidneys of all mice and in the submandibular gland of several mouse strains. The present study determined the usefulness of modified periodic acid silver-methenamine (PAM) staining for the specific detection of Ren-1 renin. METHODS: Conventional paraffin sections were prepared from kidneys of ICR, BALB/cA, C57BL/6Cr, C3H/HeN, DBA/2Cr, angiotensin II type 1a receptor gene knockout (AT1aKO) mice, Wistar rats and a human, and submandibular glands of C57BL/6Cr and DBA/2Cr mice. Sections were analyzed for the presence of renin using PAM and immunohistochemistry. PAM reactions were terminated at generally or weakly intense (weak PAM staining; W-PAM). In addition, kidneys of DBA/2Cr mice were fixed using various fixatives (formalin, PFA, PLP, Zamboni's, Bouin's, or Carnoy's) and treated using identical procedures. RESULTS: Although PAM-positive reactions were observed in juxtaglomerular (JG) cells, W-PAM reactions were particularly specific for these cells. These findings were observed in all mouse strains. Immunohistochemistry using mirror sections suggested that a W-PAM-positive reaction detected renin. This hypothesis was confirmed by the results from AT1aKO mice. Briefly, W-PAM detected an expansion of renin-positive areas in AT1aKO mice. Rat and human kidneys and mouse submandibular glands were negative for W-PAM. Levels of JG cell detection by W-PAM were similar in samples fixed in formalin, PFA, PLP, or Zamboni's. CONCLUSIONS: The present findings show that W-PAM can identify Ren-1 renin, but not Ren-2, rat or human renin. The W-PAM method is useful for the specific detection of Ren-1 renin.

Life span and renal morphological characterization of the SAMP1//Ka mouse.

The senescence-accelerated-mouse prone 1 (SAMP1) is considered to be a model of accelerated senility and it also develops severe kidney damage. The SAMP1//Ka mouse is a specific pathogen free (SPF) subline of SAMP1. The present study examined the life span of the SAMP1//Ka mouse and morphologically investigated the kidneys of this animal at 3, 4, 5, 9, 12, 15, 18 and 24 months of age. Males survived for an average of 25 months and females for 28 months. The median lifespan was 18 months for males and 20 for females. Focal cell infiltration and thickening of the basement membrane in the glomerular capsules or tubules appeared from 4 months of age. At 12 months old, glomerular lesions with expansion of the mesangial matrix and thickening of the basement membrane as well as scar lesions in the outer cortex appeared, and amyloid was deposited in the interstitium or glomeruli from 18 months of age. Morphometrically, although the area of the kidney sections was increased at 24 months of age, the diameter of the renal corpuscles, the number of nuclei of the proximal convoluted tubules and the percentage of renal corpuscles with a cuboidal glomerular capsule did not change with age. The results of the present study indicate that the life span of the SAMP1//Ka is increased and that their age-related renal changes differ from those of the original SAMP1.