Testicular Response of Non-Breeding Pheasants to Human Chorionic Gonadotropin, Chicken Pituitary Extract, and Photoperiod V. D. PUROHIT and P. K. BASRUR Department of Biomedical Sciences, University ofGuelpb, Ontario, NIG 2W1, Canada
Guelpb,
(Received for publication September 8, 1978)
INTRODUCTION G o n a d a l responses of birds t o avian and m a m m a l i a n g o n a d o t r o p i n s have b e e n r e p o r t e d t o be different (Tanaka et al., 1 9 6 6 ; Imai, 1 9 7 3 ) . Herrick et al. ( 1 9 6 2 ) r e p o r t e d t h a t testes of chicken and t u r k e y r e s p o n d e d differently t o pituitary preparations from these t w o species. F u r t h e r , Ishii and F u r u y a ( 1 9 7 5 ) suggested t h a t different species of birds m a y r e s p o n d differently t o g o n a d o t r o p i n s of a given species. This s t u d y was u n d e r t a k e n t o c o m p a r e t h e testicular
1 Present Address: Endocrine Research Laboratory, College of Medicine, Box 23, Howard University, Washington, DC 20059.
response of non-breeding pheasants t o h u m a n chorionic g o n a d o t r o p i n , chicken p i t u i t a r y extract, and e x t e n d e d p h o t o p e r i o d e x p o s u r e . MATERIALS AND METHODS Non-breeding male Ring-necked p h e a s a n t s , 5—6 m o n t h s old, were treated with 50 IU of h u m a n chorionic g o n a d o t r o p i n (HCG), e x t r a c t of five chicken anterior pituitary glands (CPE) or e x t e n d e d p h o t o p e r i o d exposure of 2 0 h r of light and 4 hr of darkness ( 2 0 L : 4 D ) for 2 0 days. HCG and CPE were injected s u b c u t a n e ously with .2 ml of saline, and t h e birds injected with these p r e p a r a t i o n s were k e p t u n d e r a light regimen of 10 h r of light a n d 1 4 h r of darkness ( 1 0 L : 1 4 D ) . Birds of t h e c o n t r o l g r o u p
TABLE 1. Testicular weights and testosterone levels in the blood plasma of male pheasants subjected to various treatments Treatment
Testicular weight Mean ± SEM (g)1
Testosterone levels Mean ± SEM (ng/100 ml) 1
Light regimen
Injections
10 hr photoperiod
Normal saline (control)
.27 ± .04*
.62 ± .13 a
10 hr photoperiod
Human chorionic gonadotropin (HCG)
.26 ± .03 a
1.11 ± . 2 1 a
10 hr photoperiod
Chicken pituitary extract (CPE)
.55 ± .04b
.89 ± .19 a
10.54 + .45 c
55.59 t .12 b
20 hr photoperiod
Sample size three. a,b,c,b and c significantly different from a and each other (P