Effect of age on immunocytochemical staining characteristics of adenohypophyseal cells in Mongolian pony mares and stallions.
OBJECTIVE
To determine the effect of age on immunocytochemical staining characteristics of adenohypophyseal cells of Mongolian pony mares and stallions.


METHODS
35 Mongolian ponies.


METHODS
Pituitary glands from 1- to 22-year-old horses of both sexes were collected at a commercial slaughterhouse in China and allocated into 7 groups according to age and sex: prepubertal stallions (n = 5; 1 to 2 years old), young stallions (6; 3 to 7 years old), middle-aged stallions (4; 10 to 12 years old), old stallions (5; 15 to 22 years old), young mares (3; 3 to 7 years old), middle-aged mares (5; 10 to 12 years old), and old mares (7; 15 to 22 years old). Pituitary glands were processed for microscopy, and sections were immunocytochemically stained for various pituitary hormones. The percentages and cell areas of 6 types of adenohypophyseal cells were determined by use of morphometry.


RESULTS
Age-related alterations in adenohypophyseal cells were detected in horses > 15 years old. Percentage of somatotrophs decreased with age regardless of sex, and percentage of lactotrophs increased with age in stallions. In old mares, percentage of follicle-stimulating hormone cells increased, whereas cell area of follicle-stimulating hormone and luteinizing hormone cells decreased. Differences between sexes for percentage of somatotrophs and lactotrophs, and cell area of follicle-stimulating hormone and luteinizing hormone cells were not evident in old horses.


CONCLUSIONS
Differences among percentages and cell areas of pituitary cell types in old horses may be associated with degeneration of the sex organs.
Tan
J H
JH
Department of Veterinary Anatomy, College of Agriculture, Osaka Prefecture University, Sakai, Japan.
Sasaki
F
F
D000324:Adrenocorticotropic Hormone / Q000032:analysis; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D005260:Female; D005640:Follicle Stimulating Hormone / Q000032:analysis; D013006:Growth Hormone / Q000032:analysis; D006736:Horses / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007986:Luteinizing Hormone / Q000032:analysis; D008297:Male; D010903:Pituitary Gland, Anterior / Q000166:cytology* / Q000502:physiology; D011388:Prolactin / Q000032:analysis; D012727:Sex Characteristics; D013972:Thyrotropin / Q000032:analysis
D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D013006:Growth Hormone