Morphometric studies on the testis of Korean ring-necked pheasant (Phasianus colchicus karpowi) during the breeding and non-breeding seasons.
The purpose of this study was to obtain detailed quantitative information on all cell types in the testis interstitium of Korean ring-necked pheasants and to combine these data with changes in the steroidogenic function of the testis during the breeding and non-breeding seasons. For animals collected during the breeding season, their testis weights, sperm production, serum testosterone levels and leuteinizing hormone (LH)-stimulated testosterone secretion were significantly (p < 0.01) increased compared to the non-breeding season. Testes of the pheasants during the non-breeding season displayed a 98% reduction in testis volume that was associated with a decrease in the absolute volume of seminiferous tubules (98% reduction), tubular lumen (100%), interstitium (90%), blood vessels (84%), lymphatic spaces (97%), Leydig cells (79%), mesenchymal cells (51%) and myoid cells (61%) compared to the breeding season. The numbers of Leydig cells, mesenchymal cells and myoid cells per testis in the breeding season were much higher than in the non-breeding season. Although the mean volume of a Leydig cell was 74% lower in the non-breeding season, the mean volumes of myoid and mesenchymal cells remained unchanged. These results demonstrate that there are striking differences in the testicular structure of the Korean ring-necked pheasant during the breeding and non-breeding seasons. Every structural parameter of the Leydig cell was positively correlated with both testosterone serum levels and LH-stimulated testosterone secretion. The correlation of changes in hormonal status with the morphometric alterations of Leydig cells suggests that the Korean-ring necked pheasant may be used as a model to study structure-function relationships in the avian testis.
Tae
H J
HJ
Bio-Safety Research Institute, College of Veterinary Medicine, Chonbuk National University, Chonju, 561-756, Republic of Korea.
Jang
B G
BG
Ahn
D C
DC
Choi
E Y
EY
Kang
H S
HS
Kim
N S
NS
Lee
J H
JH
Park
S Y
SY
Yang
H H
HH
Kim
I S
IS
D000818:Animals; D046094:Galliformes / Q000033:anatomy & histology* / Q000502:physiology*; D007723:Korea; D007986:Luteinizing Hormone / Q000494:pharmacology; D008297:Male; D009929:Organ Size / Q000502:physiology; D012098:Reproduction / Q000502:physiology*; D012621:Seasons; D013094:Spermatozoa / Q000502:physiology; D013737:Testis / Q000033:anatomy & histology* / Q000166:cytology / Q000187:drug effects; D013739:Testosterone / Q000097:blood
D013739:Testosterone; D007986:Luteinizing Hormone