Relationship between changes in mitotic activity of the corneal epithelium and body weight of fasting animals

1961 ◽  
Vol 50 (6) ◽  
pp. 1317-1321
Author(s):  
O. T. Movchan
Keyword(s):  
Body Weight ◽  
Mitotic Activity ◽  
Corneal Epithelium

THE EFFECT OF ADRENALECTOMY AND ADRENOCORTICAL HORMONES ON THE HAIR GROWTH CYCLE IN THE RABBIT AND RAT

1958 ◽  
Vol 17 (2) ◽  
pp. 167-NP ◽  
Author(s):  
H. J. WHITELEY
Keyword(s):  
Body Weight ◽  
Mitotic Activity ◽  
Hair Growth ◽  
Inhibitory Action ◽  
Growth Cycle ◽  
Bilateral Adrenalectomy ◽  
Hair Regrowth ◽  
Cycle Growth ◽  
The Difference

SUMMARY The effect of cortisone and adrenalectomy on the hair regrowth cycle of the rat and rabbit was investigated. It was found that bilateral adrenalectomy had no effect on the rate of regrowth of hair or on the quality of the coat in the rabbit, but there was decreased mitotic activity of the follicles on the 2nd and 7th day of the regrowth cycle and increased mitotic activity of the epidermis on the 7th day of this cycle. In the rat bilateral adrenalectomy, apart from causing a generalized wave of hair growth, which was not observed in the rabbit, had no effect on the hair regrowth cycle. The local application of hydrocortisone had a slight inhibitory action in the early stages of the cycle, but i.m. injection of cortisone produced profound inhibition. In the rabbit doses of 12·5 mg/kg body weight caused suppression of the usual regrowth cycle, but in some animals the outercoat hairs were unaffected. There was depression of the mitotic activity of the epidermis on the 7th and 10th days of the cycle. If cortisone was given during different stages of the regrowth cycle growth of undercoat hair was much more inhibited than that of the outercoat hair. Similar results were observed in the rat. These results are discussed and it is postulated that the difference in response between the two types of hair might be related to differences in blood supply of the outercoat and undercoat hairs.

scholarly journals Effects of Internally Administered N-[5-( 4-Aminophenoxy)Pentyl]Phthalimide on Wool Follicles and Skin of Sheep

1980 ◽  
Vol 33 (2) ◽  
pp. 183 ◽  
Author(s):  
RE Chapman ◽  
RDG Rigby
Keyword(s):  
Body Weight ◽  
Cell Division ◽  
Mitotic Activity ◽  
Sebaceous Gland ◽  
Skin Surface ◽  
Skin Thickness ◽  
Sebaceous Glands ◽  
Wool Follicle ◽  
Dark Staining ◽  
Dermal Papillae

When N-[5-(4-aminophenoxy)pentyl]phthalimide was administered to sheep in sufficient quantities to permit manual removal of the fleece (400 mg/kg body weight orally, or 75 mg/kg body weight intravenously during a period of 48 h), cell division ceased in the wool follicle bulbs within 1 day. Dark-staining bodies (autophagic vacuoles) developed concomitantly in the cytoplasm of the bulb cells. The nuclei of cells in the keratogenous zones of the fibres became pycnotic 2 days after dosing and subsequent keratinization of these portions of the fibres was impaired. All the follicles retrogressed prior to day 7 after dosing, and the root ends which formed on the fibres moved towards the skin surface, reaching the level of the sebaceous glands by day 7. At this time mitotic activity recommenced around the dermal papillae in about 50% of the follicles. A small number of tips of new fibres emerged from the skin surface of some of the depilated sheep by day 14. The root ends on the fibres in the fleeces harvested at days 7-15 were fragmented with various degrees of taper. By 21 days, most follicles were growing emergent fibres. Thickening of the epidermis, increase in sebaceous gland size and decrease in skin thickness occurred in some of the depilated sheep.

ON THE DIURNAL CYCLE OF MITOTIC ACTIVITY IN THE CORNEAL EPITHELIUM OF MICE

1958 ◽  
Vol 33 (3) ◽  
pp. 230-237 ◽  
Author(s):  
Raimo Vasama ◽  
Ritva Vasama
Keyword(s):  
Mitotic Activity ◽  
Diurnal Cycle ◽  
Corneal Epithelium
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